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33 results on '"Laboratoire d'Etudes de Mécanique Sismique (EMSI)"'

1. Efficiency of viscoelastic interstructural connections to prevent earthquake induced pounding

Author

V. Crozet, Ioannis Politopoulos, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
[SPI]Engineering Sciences [physics], business.industry, Earth and Planetary Sciences (miscellaneous), Structural engineering, Geotechnical Engineering and Engineering Geology, Active control, business, Viscoelasticity, Geology, Civil and Structural Engineering
Abstract

This work deals with the efficacy of viscoelastic connections in preventing pounding without undesirable adverse effects on the coupled structures. To this end, the earthquake response of two oscillators, coupled with optimally designed passive viscoelastic and active devices as well as with rigid connections, was studied. A particular attention was given to two issues: (a) the upper limit of the device force and (b) the capacity of the device in reducing the interstructures displacement to avoid collision. The main conclusion of the paper is that, in general, there is no substantial benefit from the use of viscoelastic connections as a means to prevent pounding.

Published
2020
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2. Modular implementation framework of partitioned path-following strategies: Formulation, algorithms and application to the finite element software Cast3M

Author

Benjamin Richard, Ibrahim Bitar, Giuseppe Rastiello, Hugo Luiz Oliveira, Alain Millard, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Mécanique Systèmes et Simulation (LM2S), Laboratoire de Modélisation et d’Analyse de la Performance des Structures (IRSN/PSN-EXP/SES/LMAPS), Service d'Expertise des équipements et des Structures (IRSN/PSN-EXP/SES), and Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

Subjects
Formalism (philosophy), Computer science, business.industry, General Engineering, Modular design, Displacement (vector), Domain (software engineering), Set (abstract data type), Nonlinear system, [SPI]Engineering Sciences [physics], Software, Focus (optics), business, Algorithm
Abstract

International audience; Damaging, cracking, and strain localization mechanisms often lead to unstable structural responses characterized by snap-backs(i.e., the force and the displacement decrease simultaneously). The usual nonlinear Newton-based solution algorithms with displacement/force control cannot capture the complete equilibrium curve in a numerical context. This shortcoming can be circumventedusing path-following formulations. They rely on two hypotheses: (i) the decomposition of loading into two parts, one knownand the other unknown (only its direction is imposed); (ii) the use of path-following equations so that the unknown load (forceor displacement) contribution can be determined indirectly. Collecting the essential concepts and the formalism of path-followingarc-length methods, we design a unique framework into the Cast3M toolbox, capable of receiving existing and new path-followingequations without significant modifications. Three path-following constraints were chosen to demonstrate its applicability: a constrainton the combination of the displacement increment at a given set of nodes, a constraint on the maximum strain incrementover the computational domain, and a constraint on the maximum elastic predictor of the damage/plastic criterion function over thecomputational domain. Two- and three- dimensional strain localization simulations show that the proposed framework behaves ina stable and convergent manner, even in the presence of multiple severe snap-back instabilities. The proposed study proves helpfulbecause the user can focus on developing new path-following equations into the Cast3M toolbox. The developments discussed inthis manuscript will be made available to the users/developers community with Cast3M 2021 (release date: April 2021).

Published
2021
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3. Influence of Input Motion's Control Point Location in Nonlinear SSI Analysis of Equipment Seismic Fragilities: Case Study on the Kashiwazaki-Kariwa NPP

Author

Cyril Feau, Fan Wang, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Propagation of uncertainty, business.industry, Process (computing), Structural engineering, 010502 geochemistry & geophysics, Motion control, 01 natural sciences, law.invention, Nonlinear system, [SPI]Engineering Sciences [physics], Geophysics, Fragility, Geochemistry and Petrology, law, Soil structure interaction, Nuclear power plant, Sensitivity (control systems), business, Geology, 0105 earth and related environmental sciences
Abstract

The aim of this case study is to evaluate the influence of input seismic motion control point on the fragility curves of some nuclear power plant’s equipment considering (1) a strong soil–structure interaction problem and (2) the variability of the input seismic signals. To this end, a current engineering methodology was implemented for computation efficiency, based on a simplified model representing the largely embedded Unit 7 reactor building of the Kashiwazaki-Kariwa NPP (Japan). Seismic signals were generated with NGA GMPE according to the July 2007 NCOE scenario. In the process, soil non-linearity caused by each seismic signal was taken into account using the equivalent linear method. A study on the uncertainty propagation through the simplified soil–structure system is also presented. It allowed the implementation of an empirical sensitivity analysis to confirm the main results, which suggest that defining the control point of the input motion at the soil surface as prescribed in the French nuclear practice is not appropriate and may lead to biased outcomes when performing non-linear soil–structure fragility analysis. Instead, it should be defined at the “outcropping bedrock” level.

Published
2020
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4. Use of response envelopes for seismic margin assessment of reinforced concrete walls and slabs

Author

Nicolas Ile, Alberto Frau, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Nuclear and High Energy Physics, Engineering, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 0211 other engineering and technologies, Shell (structure), 020101 civil engineering, 02 engineering and technology, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 0201 civil engineering, Structural element, Margin (machine learning), elliptical envelope, General Materials Science, Geotechnical engineering, Safety, Risk, Reliability and Quality, Waste Management and Disposal, 021110 strategic, defence & security studies, Basis (linear algebra), business.industry, Mechanical Engineering, Linear elasticity, walls, Linearity, Structural engineering, Finite element method, Stress field, Nuclear Energy and Engineering, seismic, business
Abstract

International audience; Seismic safety evaluations of existing nuclear facilities are usually based on the assumption of structural linearity. For the design basis earthquake (DBE), it is reasonable to apply a conventional evaluation of the seismic safety of building structures and carry out a linear elastic analysis to assess the load effects on structural elements. Estimating the seismic capacity of a structural element requires an estimation of the critical combination of responses acting in this structural element and compare this combination with the capacity of the element. By exploiting the response-spectrum-based procedure for predicting the response envelopes in linear structures formulated by Menun and Der Kiureghian (2000a), algorithms are developed for the seismic margin assessment of reinforced concrete shell finite elements. These algorithms facilitate the comparison of the response-spectrum-based envelopes to prescribed capacity surfaces for the purpose of assessing the safety margin of this kind of structures. The practical application of elliptical response envelopes in case of shell finite elements is based on the use of layer models such as those developed by Marti (1990), which transfer the generalized stress field to three layers under the assumption that the two outer layers carry membrane forces and the internal layer carries only the out-of-plane shears. The utility of the assessment approach is discussed with reference to a case study of a 3D structure made of reinforced concrete walls.

Published
2017
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5. Shake table tests of structures subject to pounding

Author

Thierry Chaudat, Ioannis Politopoulos, V. Crozet, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
floor response spectra, [SPI]Engineering Sciences [physics], shake table test, pounding, business.industry, Earth and Planetary Sciences (miscellaneous), Earthquake shaking table, Subject (documents), Structural engineering, Geotechnical Engineering and Engineering Geology, business, Geology
Abstract

Pounding between adjacent structures during earthquakes may significantlymodify their response in terms of forces and displacements. In addition, it hasa considerable influence on acceleration and thus on floor response spectra.Therefore, pounding may be unfavorable to the response of equipment. Despiteextensive research in this field, the effects of pounding on structures are difficultto quantify accurately. This article presents results of shake table tests carried outon two representative scale adjacent structures subject to pounding. Besidesinvestigating the effects of the gap between structures and the excitation signal,this study examines also the effect of tying the two structures together by meansof rigid links to suppress pounding. The results of the experimental campaign arethen compared with those of numerical simulations. Analyses and experimentalresults show good agreement regarding both impact forces and interstorey drifts

Published
2019
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6. CastLab: an object-oriented finite element toolbox within the Matlab environment for educational and research purposes in computational solid mechanics

Author

Romili Paredes, Cédric Giry, Francesco Riccardi, Giuseppe Rastiello, Chaymaa Lejouad, Eliass Zafati, Santosh Kakarla, Benjamin Richard, Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Modélisation et d’Analyse de la Performance des Structures (IRSN/PSN-EXP/SES/LMAPS), Service d'Expertise des équipements et des Structures (IRSN/PSN-EXP/SES), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

Subjects
Object-oriented programming, Computer science, business.industry, General Engineering, 02 engineering and technology, 01 natural sciences, Finite element method, Toolbox, 010101 applied mathematics, [SPI]Engineering Sciences [physics], 020303 mechanical engineering & transports, 0203 mechanical engineering, Computational mechanics, Solid mechanics, Feature (machine learning), Key (cryptography), 0101 mathematics, MATLAB, Software engineering, business, computer, Software, ComputingMilieux_MISCELLANEOUS, computer.programming_language
Abstract

International audience; The Matlab environment has become widely used among the computational mechanics community, not only for research purposes but also to teach either undergraduate or graduate classes. This paper aims to present a new toolbox devoted to computational mechanics and in particular to solid mechanics. Both recent and well-established numerical formulations have been implemented in it. One of its strengths resides in the fact that it was developed within an object-oriented framework. This key feature makes the CastLab toolbox easy-to-use and with extensive capabilities for customized user developments. After a brief description of the theoretical background related to the problems that can be solved by means of the toolbox, several representative case-studies are presented. These examples have been selected to illustrate not only the numerical efficiency of the toolbox, which is of primary importance for research purposes, but also its strong educational and pedagogic potential.

Published
2019
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7. SMART 2013: Lessons learned from the international benchmark about the seismic margin assessment of nuclear RC buildings

Author

François Voldoire, Maxime Fontan, Thierry Chaudat, Salim Abouri, Nicolas Bonfils, Jacky Mazars, Benjamin Richard, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), EDF (EDF), OXAND, Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), ANR-13-IS02-0001,SMArT,Satisfaisabilité Modulo Arithmétique et Théories(2013), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Peak ground acceleration, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Shear walls assembly, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 0201 civil engineering, Seismic analysis, 021105 building & construction, Cast3M, Aftershock, Civil and Structural Engineering, SMART, business.industry, Seismic loading, Torsion (mechanics), Numerical models, Structural engineering, shaking table tests, Reinforced concrete, Nuclear power plant, Seismic safety margins, Earthquake shaking table, business, Geology, Reinforced Concrete
Abstract

International audience; In this paper, the main findings and conclusions drawn from the second international benchmark named SMART 2013 and jointly organized by the French Sustainable Energies and Atomic Energy Commission (CEA) and Electricité De France (EDF) within the framework of a wide research program entitled “Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effects” (SMART) are presented. A 1:4-scaled reinforced concrete (RC) specimen, representing a part of a nuclear auxiliary building and designed according to French guidelines for a PGA level equal to 0.2 g, was subjected to shaking table tests; results of this experimental campaign are used as reference data for this benchmark. The input ground motions considered in the seismic loading sequence are mainly natural bi-axial signals (main shock and aftershock) recorded during the Northridge earthquake that took place in California, USA in 1994 and have a PGA (Peak Ground Acceleration) about 1.8 g. These high-intensity seismic loadings allow assessing the relevancy of nonlinear numerical models when they have to deal with strong nonlinearities due to concrete cracking. The results produced by the 42 teams which participated in the international benchmark show that (i) the dynamic behavior of the specimen is well captured when dealing with the design level, (ii) the displacement are underestimated when dealing with the beyond design behavior, (iii) the peak frequency shifts are well captured and (iv) the damaging effect of the Northridge aftershock is almost null. Last, seismic safety margins of the specimen are quantified by two mechanical indicators; the results confirm the fact that the RC specimen which was designed according to the codes applicable in the French nuclear industry, exhibits noticeable good performance level regarding collapse prevention.

Published
2018
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8. Floor response spectra of a partially embedded seismically isolated nuclear plant

Author

Ioannis Politopoulos, Ion Sergis, Fan Wang, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Engineering, Soil–structure interaction, Embedment, business.industry, Foundation (engineering), Soil Science, Seismic isolation, Structural engineering, Nuclear power, Geotechnical Engineering and Engineering Geology, Spectral line, Finite element method, law.invention, [SPI]Engineering Sciences [physics], law, Soil structure interaction, Nuclear power plant, Rocking excitation, Floor response spectra, business, Excitation, Civil and Structural Engineering
Abstract

International audience; This paper deals with the effects of foundation embedment on the floor response spectra of big base isolated structures such as nuclear power plants. Analyses of a finite element model, representative of a real nuclear power plant, have been carried out. It has been demonstrated that, in agreement with previous work, base rocking excitation, induced by soil–structure interaction, may amplify the non-isolated modes׳ response and thus it must not be overlooked.

Published
2015
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9. A new semi-active control based on nonlinear inhomogeneous optimal control for mixed base isolation

Author

Ioannis Politopoulos, Sette Diop, Duc Chuan Vu, Human Genetics Division (Mp 808), Laboratoire des signaux et systèmes (L2S), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
021110 strategic, defence & security studies, Engineering, Computer simulation, business.industry, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Building and Construction, Interval (mathematics), Optimal control, Displacement (vector), 0201 civil engineering, Damper, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Nonlinear system, [SPI]Engineering Sciences [physics], Autoregressive model, Mechanics of Materials, Control theory, Base isolation, business, Civil and Structural Engineering
Abstract

International audience; This paper presents a control algorithm for seismic mixed base isolation, combining passive isolators and semi-active viscous dampers. The objective is to limit base displacement while avoiding undesirable amplification of the response of the non-isolated modes. To this end, the proposed algorithm takes into account the constraints on the damping coefficient of the semi-active damper and information on the excitation. It is based on the approximate iterative solution, at each control time step, of a nonlinear inhomogeneous constrained optimal control problem. An autoregressive model is used to obtain, at each control time step, a prediction of the upcoming excitation in a short time interval ahead. Numerical simulation results demonstrate the efficacy of the above method, especially in improving floor response spectra, and its superiority with respect to clipped-optimal algorithms.

Published
2018
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10. Dissipations in reinforced concrete components Static and dynamicexperimental identification strategy

Author

Thomas Heitz, A. Le Maoult, Frédéric Ragueneau, Cédric Giry, B. Richard, CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de mécanique et technologie (LMT), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Damping ratio, RC beam, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Computer science, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Damping, 0201 civil engineering, Atomic energy commission, Set (abstract data type), 021105 building & construction, TAMARIS, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering, business.industry, Structural engineering, Dissipation, Reinforced concrete, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Nonlinear system, Identification (information), IDEFIX, Earthquake shaking table, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, business
Abstract

International audience; Despite their now well documented drawbacks, viscous damping based models to describe the dissipationsoccurring in reinforced concrete (RC) structures during seismic events are popular among structural engineers.Their computational efficiency and their convenient implementation and identification are indeed attractive. Ofcourse, the choice of a viscous damping model is, most of the time, reasonable, but some questions still arisewhen it comes to calibrate its parameters how do these parameters evolve through the nonlinear time-historyanalysis? How do they interact when several eigenmodes are involved? To address these questions, the IDEFIXexperimental campaign (French acronym for Identification of damping-dissipations in RC structural elements) hasbeen carried out on RC beams set up on the Azalee shaking table of the TAMARIS experimental facility operatedby the French Alternative Energies and Atomic Energy Commission (CEA). First, this experimental campaign ispositioned within an overview of related experimental campaigns in the literature. Second, the IDEFIX experimental campaign is presented. In particular, noticeable results are given by examples of first post-treatments,including an improved so-called areas method, which lead to very different identified damping ratio depending on the method used.

Published
2018
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11. A discrete anisotropic damage constitutive law with an enhanced mixed-mode kinematics: Application to RC shear walls

Author

Ejona Kishta, Cédric Giry, Benjamin Richard, Frédéric Ragueneau, Mikel Balmaseda, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), and ANR-11-RSNR-0022,SINAPS@,Séisme et Installation Nucléaire -Améliorer et Pérenniser la Sûreté(2011)

Subjects
Materials science, Constitutive equation, 02 engineering and technology, Classification of discontinuities, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], 01 natural sciences, Displacement (vector), Discontinuity (geotechnical engineering), 0203 mechanical engineering, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Shear wall, General Materials Science, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, business.industry, Mechanical Engineering, Mechanics, Structural engineering, Finite element method, 010101 applied mathematics, Cracking, 020303 mechanical engineering & transports, Mechanics of Materials, Fracture (geology), business, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire
Abstract

The concept of displacement discontinuities embedded into standard finite elements allows efficient modeling of regions exhibiting localized strains, e.g. fracture of quasi-brittle materials. The present paper addresses the issue of fine cracking representation and the formulation of an enhanced anisotropic model to capture anisotropic cracking failure of reinforced concrete specimens. A damage-based constitutive law accounting, in a natural manner, for particular crack families orientation is used. This latter is enhanced with a mixed-mode strong discontinuity kinematics providing a discrete model expressed in terms of the displacement jump. The formulation and the finite element implementation are described. A shear wall under cyclic loading is studied. The results obtained are compared to the experimental ones. It is shown that the proposed model succeeds in reproducing accurately the anisotropic cracking and the unilateral effect.

Published
2017
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12. Toward an integrated seismic risk assessment for nuclear safety improving current French methodologies through the SINAPS@ research project

Author

Thomas Chartier, Ejona Kishta, Julie Régnier, Nadim Moussallam, Frédéric Ragueneau, Cédric Guyonnet-Benaize, Fabian Bonilla, Marc Nicolas, François Voldoire, Silvano Erlicher, Pierre-Yves Bard, Vincent Perron, Fabrice Hollender, Fabien Banci, Irmela Zentner, Panagiotis Kotronis, Alain Le Maoult, Nikolaos Theodoulidis, Benjamin Richard, Angkeara Svay, Stéphane Grange, Aurore Laurendeau, Fernando Lopez-Caballero, M. Lancieri, Catherine Berge-Thierry, Régis Cottereau, Laboratoire de mécanique des sols, structures et matériaux (MSSMat), Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Laboratoire de Détection et de Géophysique (CEA) (LDG), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA-CESTA), Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, EDF (EDF), Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), AREVA, Groupe AREVA, Laboratoire sols, solides, structures - risques [Grenoble] (3SR), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), EGIS, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Equipe-projet MOUVGS (Cerema Equipe-projet MOUVGS), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), Séismes et Vibrations (IFSTTAR/GERS/SV), Communauté Université Paris-Est-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), SINAPS@ ANR-11-RSNR-0022,SINAPS@,SINAPS@: Séisme & Installations Nucléaires: Assurer et Pérenniser la Sûreté, CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Laboratoire sols, solides, structures - risques [Grenoble] (3SR ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Risques, Vulnérabilité des structures et comportement mécanique des matériaux (RV ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), ANR-11-RSNR-0022,SINAPS@,Séisme et Installation Nucléaire -Améliorer et Pérenniser la Sûreté(2011), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), and Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est

Subjects
Nuclear and High Energy Physics, Engineering, 010504 meteorology & atmospheric sciences, Design strategy, 010502 geochemistry & geophysics, 7. Clean energy, 01 natural sciences, Civil engineering, Construction engineering, Seismic analysis, law.invention, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], law, Vulnerability assessment, Multidisciplinary approach, Nuclear power plant, General Materials Science, Seismic risk, Safety, Risk, Reliability and Quality, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, business.industry, Mechanical Engineering, Seismic hazard, Nuclear Energy and Engineering, 13. Climate action, business, Risk assessment
Abstract

International audience; The Tohoku earthquake and associated tsunami in March 2011 caused a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant, where level 7 (International Atomic Energy Agency (IAEA) – INES scale) meltdown at three reactors occurred. The underestimation of the seismic and tsunami hazards has been recognized and the seismic margins assessment of the nuclear plants remains a priority for the whole nuclear community. In this framework a five-year research project called SINAPS@ (Earthquake and Nuclear Installations: Ensuring and Sustaining Safety) is currently on-going in France. A reliable estimate of seismic margins is possible only if all uncertainties, epistemic and aleatory, are effectively identified, quantified and integrated in the seismic risk analysis. SINAPS@ brings together a multidisciplinary community of researchers and engineers from the academic and the nuclear world. SINAPS@ aims at exploring the uncertainties associated to databases, physical processes and methods used at each stage of seismic hazard, site effects, soil and structure interaction, structural and nuclear components vulnerability assessments, in a safety approach: the main objective is ultimately to identify the sources of potential seismic margins resulting from assumptions or when selecting the seismic design level or the design strategy. The whole project is built around an “integrating” work package enabling to test state-of-the-art practices and to challenge new methodologies for seismic risk assessment: the real case of Kashiwazaki-Kariwa Japanese nuclear plant, shocked by the severe earthquake in 2007 provided a rich dataset which will be used to compare with the predictions. The present paper proposes for each step of the seismic risk analysis a review of the state of practice in France in the nuclear field and then precise the objectives and research strategy of SINAPS@ to overcome identified limitations or weaknesses. Scientific issues are illustrated through preliminary results of the project.

Published
2017
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13. Strong discontinuity analysis of a class of anisotropic continuum damage constitutive models – Part II: Concrete material application

Author

Frédéric Ragueneau, Benjamin Richard, Cédric Giry, Ejona Kishta, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Engineering, Induced anisotropy, Constitutive equation, 0211 other engineering and technologies, 02 engineering and technology, 0203 mechanical engineering, Robustness (computer science), [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], General Materials Science, Anisotropy, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, Civil and Structural Engineering, Mathematical logic, Continuum (measurement), business.industry, Continuous modelling, Mechanical Engineering, Mathematical analysis, Structural engineering, 16. Peace & justice, Condensed Matter Physics, 020303 mechanical engineering & transports, Mechanics of Materials, Jump, business
Abstract

On the basis of the strong discontinuity analysis, a discrete model expressed in terms of traction vector-displacement jump has been constructed from a continuous model expressed in terms of stress–strain law. In the first part of the paper, this approach has been extended to a class of anisotropic continuum damage constitutive models [1] . In this second part of the paper, the proposed class of discrete anisotropic damage constitutive models is particularized. More precisely, a micromechanical-based anisotropic damage constitutive model is derived. This model accounts in a natural manner for particular crack families orientation. The aims of this paper are (i) to illustrate the capabilities of the proposed discrete enhanced model in reproducing the induced anisotropy appearing in quasi-brittle materials when cracking and (ii) to assess the numerical robustness of the time integration scheme. For this purpose, two numerical examples at the material point level are exposed after a brief presentation of the time integration scheme. The correspondence between the continuous and the discrete model as well as the induced anisotropy features are emphasized.

Published
2017
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14. Beam-particle approach to model cracking and energy dissipation in concrete: Identification strategy and validation

Author

Frédéric Ragueneau, Maxime Vassaux, Benjamin Richard, Cécile Oliver-Leblond, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Cracking, Identification, Materials science, 02 engineering and technology, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], 0203 mechanical engineering, Energy Dissipation, Lattice (order), [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], General Materials Science, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, business.industry, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Building and Construction, Structural engineering, [PHYS.MECA]Physics [physics]/Mechanics [physics], Dissipation, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], [INFO.INFO-NA]Computer Science [cs]/Numerical Analysis [cs.NA], Beam-particle model, 010101 applied mathematics, 020303 mechanical engineering & transports, Test case, Peak load, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, [SPI.GCIV.MAT]Engineering Sciences [physics]/Civil Engineering/Matériaux composites et construction, business, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire
Abstract

International audience; This paper focuses on the application of a beam-particle model to study the failure of concrete under complex loading. The formulation of the model is based both on lattice models and discrete elements models in order to capture cohesion, failure and frictional contact of the crack surfaces. To correctly describe the elastic phase, the peak load and the post-peak phase, the failure criteria is discussed and heterogeneities are introduced. The calibration of this model is detailed and illustrated. Finally, several test cases are analysed in order to validate the model.

Published
2016
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15. SMART 2013: Experimental and numerical assessment of the dynamic behavior by shaking table tests of an asymmetrical reinforced concrete structure subjected to high intensity ground motions

Author

Thierry Chaudat, François Voldoire, Benjamin Richard, Nicolas Bonfils, Salim Abouri, Stefano Cherubini, Pierre-Etienne Charbonnel, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), EDF (EDF), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Structures & Simulations, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
021110 strategic, defence & security studies, Engineering, business.industry, media_common.quotation_subject, Seismic loading, 0211 other engineering and technologies, Torsion (mechanics), 020101 civil engineering, Numerical assessment, 02 engineering and technology, Structural engineering, Reinforced concrete, Asymmetry, 0201 civil engineering, Nonlinear system, [SPI]Engineering Sciences [physics], Earthquake shaking table, business, Aftershock, Civil and Structural Engineering, media_common
Abstract

International audience; As part of a large research program launched and funded by the French Atomic Energy and Sustainable Energies Commission (CEA) and Electricité De France (EDF), partially supported by the International Atomic Energy Agency (IAEA) and entitled ‘‘Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effect (SMART)”, a series of shakingtable tests on a ¼-scale 3-story reinforced concrete model characterized by a strong asymmetry has been carried out in July 2013. The seismic loading was composed of three test sequences having different peak ground accelerations (PGA): the design level signal (PGA equal to 0.2 g), the Northridge main shock signal (PGA equal to 1.78 g) and a Northridge aftershock (PGA equal to 0.33 g). In this paper, the main experimental results, compared with outputs from a numerical study carried out by CEA, are presented and discussed. The following conclusions were reached for each seismic test sequence: (i) only small nonlinearities appeared and both displacement and acceleration-based quantities were properly estimated by the model; (ii) the specimen exhibited moderate nonlinearities in case of PGA higher than 4 or 5 times the design PGA; displacements were numerically underestimated whereas maximum acceleration-based quantities were captured rather well; (iii) the fact that no additional damage was monitored during this seismic sequence was pointed out only by the experimental measurements but also by the numerical outputs, leading to show that this aftershock signal did not induce any further damage. Given the aforementioned observations, it was possible to carry out a robustness analysis based upon two damage indicators: the eigenfrequency shift and the inter-story drift. Apart from the issues of the most meaningful robustness indicator and the choice of damage thresholds that came up, it is shown that the specimen can be qualified as being robust.

Published
2016
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16. Model updating techniques for damage detection in concrete beam using optical fiber strain measurement device

Author

Xavier Chapeleau, Bojana Rosić, V. le Corvec, P.-E. Charbonnel, E. Merliot, Dominique Siegert, Julien Waeytens, Louis Marie Cottineau, R. Vidal, Laboratoire Instrumentation, Simulation et Informatique Scientifique (IFSTTAR/COSYS/LISIS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Statistical Inference for Structural Health Monitoring (I4S), Département Composants et Systèmes (IFSTTAR/COSYS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Lille Nord de France-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Lille Nord de France-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Lille Nord de France, Advitam, Numerical Engineering & Consulting Services [Sceaux] (NECS), Structure et Instrumentation Intégrée (IFSTTAR/COSYS/SII), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM), Communauté Université Paris-Est-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Département Composants et Systèmes (IFSTTAR/COSYS), PRES Université Lille Nord de France-PRES Université Nantes Angers Le Mans (UNAM)-Université de Lyon-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Lille Nord de France-PRES Université Nantes Angers Le Mans (UNAM)-Université de Lyon-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), and PRES Université Lille Nord de France-PRES Université Nantes Angers Le Mans (UNAM)-Université de Lyon-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)

Subjects
Engineering, Optical fiber, business.industry, Bayesian probability, Constitutive equation, Statistical model, 02 engineering and technology, Structural engineering, Inverse problem, 021001 nanoscience & nanotechnology, Finite element method, law.invention, Tikhonov regularization, 020303 mechanical engineering & transports, [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], 0203 mechanical engineering, law, Structural health monitoring, 0210 nano-technology, business, Algorithm, Civil and Structural Engineering
Abstract

The article aims at detecting and quantifying early structural damages using deterministic and probabilistic model updating techniques. To achieve this purpose, local information in a form of optical strain measurement is employed. The strategy consists in updating physical parameters associated to damages, such as Young’s modulus, in order to minimize the gap between the numerical strain obtained from finite element solves and the strain sensor outputs. Generally, the damage estimation is an ill-posed inverse problem, and hence requires regularization. Herein, three model updating techniques are considered involving different type of regularization: classical Tikhonov regularization, Constitutive Relation Error based updating method and Bayesian approach. An illustration of these three approaches is proposed for localizing and quantifying an early damage in a real 8 meter post-tensioned concrete beam. Numerical results show that all the methods properly localize the damaged area and give similar estimation of the damage level

Published
2016
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17. International Benchmark on Numerical Simulations for 1D, Nonlinear Site Response (PRENOLIN): Verification Phase Based on Canonical Cases

Author

Gaetano Falcone, Fabrice Hollender, Alborz Ghofrani, Mahdi Taiebat, Michael Musgrove, Pierre-Yves Bard, Evangelia Garini, George Gazetas, Daniela Boldini, Luca Verrucci, Kohei Watanabe, Luis Fabian Bonilla, Aneta Richterova, Alex Nieto-Ferro, Peter Moczo, Annamaria di Lernia, Long Chen, Jian Shi, Boris Jeremić, Federico Pisanò, Stavroula Kontoe, Céline Gélis, Steve Kramer, James R. Gingery, Angelo Amorosi, Evelyne Foerster, Domniki Asimaki, Joseph Harmon, Julie Régnier, Sebastiano Foti, Jozef Kristek, Alessandro Pagliaroli, Giuseppe Tropeano, Anna Chiaradonna, Youssef M. A. Hashash, Silvana Montoya-Noguera, Maria Paola Santisi d'Avila, Francesco Silvestri, Susumu Iai, Florent Demartin, Nathalie Glinsky, Marco Ebrille, Fernando Lopez-Caballero, Suwal Sajana, Etienne Bertrand, Deborah Sicilia, Amalia Giannakou, Graeme McAllister, E. Diego Mercerat, Pedro Arduino, Hiroshi Kawase, Giuseppe Lanzo, Ahmed Elgamal, Marianne Marot, Régnier, Julie, Bonilla, Luis‐fabian, Bard, Pierre‐yve, Bertrand, Etienne, Hollender, Fabrice, Kawase, Hiroshi, Sicilia, Deborah, Arduino, Pedro, Amorosi, Angelo, Asimaki, Domniki, Boldini, Daniela, Chen, Long, Chiaradonna, Anna, Demartin, Florent, Ebrille, Marco, Elgamal, Ahmed, Falcone, Gaetano, Foerster, Evelyne, Foti, Sebastiano, Garini, Evangelia, Gazetas, George, Gélis, Céline, Ghofrani, Alborz, Giannakou, Amalia, Gingery, James R., Glinsky, Nathalie, Harmon, Joseph, Hashash, Youssef, Iai, Susumu, Jeremić, Bori, Kramer, Steve, Kontoe, Stavroula, Kristek, Jozef, Lanzo, Giuseppe, Lernia, Annamaria di, Lopez‐caballero, Fernando, Marot, Marianne, Mcallister, Graeme, Diego Mercerat, E., Moczo, Peter, Montoya‐noguera, Silvana, Musgrove, Michael, Nieto‐ferro, Alex, Pagliaroli, Alessandro, Pisanò, Federico, Richterova, Aneta, Sajana, Suwal, Santisi d'Avila, Maria Paola, Shi, Jian, Silvestri, Francesco, Taiebat, Mahdi, Tropeano, Giuseppe, Verrucci, Luca, Watanabe, Kohei, Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Equipe-projet MOUVGS (Cerema Equipe-projet MOUVGS), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), Séismes et Vibrations (IFSTTAR/GERS/SV), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Disaster Prevention Research Institute, Kyoto University [Kyoto], Département de sismologie (DS (UMR_7580)), IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Laboratoire de mécanique des sols, structures et matériaux (MSSMat), Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Régnier, J., Bonilla, L.F., Bard, P.Y., Bertrand, E., Hollender, F., Kawase, H., Sicilia, D., Arduino, P., Amorosi, A., Asimaki, D., Boldini, D., Chen, L., Chiaradonna, A., Demartin, F., Ebrille, M., Elgamal, A., Falcone, G., Foerster, E., Foti, S., Garini, E., Gazetas, G., Gélis, C., Ghofrani, A., Giannakou, A., Gingery, J.R., Glinsky, N., Harmon, J., Hashash, Y., Iai, S., Jeremić, B., Kramer, S., Kontoe, S., Kristek, J., Lanzo, G., di Lernia, A., Lopez-Caballero, F., Marot, M., Mcallister, G., Mercerat, E.D., Moczo, P., Montoya-Noguera, S., Musgrove, M., Nieto-Ferro, A., Pagliaroli, A., Pisanò, F., Richterova, A., Sajana, S., Santisi d'Avila, M.P., Shi, J., Silvestri, F., Taiebat, M., Tropeano, G., Verrucci, L., Watanabe, K., Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Disaster Prevention Research Institute (DPRI), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Centre National de la Recherche Scientifique (CNRS), Kyoto University, Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Geochemistry & Geophysics, Peak ground acceleration, Earthquake, Wave propagation, Computation, 0211 other engineering and technologies, 0404 Geophysics, 02 engineering and technology, Seismic, 010502 geochemistry & geophysics, Civil Engineering, 01 natural sciences, 0905 Civil Engineering, Viscoelasticity, Ground response analysis, Geochemistry and Petrology, Applied mathematics, Boundary value problem, seismic response analysis, numerical modelling, ComputingMilieux_MISCELLANEOUS, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Mathematics, Geophysics, Computer simulation, business.industry, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Structural engineering, Dissipation, Nonlinear system, geophysics, geochemistry and petrology, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, business
Abstract

© 2016 Seismological Society of America. All rights reserved. PREdiction of NOn-LINear soil behavior (PRENOLIN) is an international benchmark aiming to test multiple numerical simulation codes that are capable of predicting nonlinear seismic site response with various constitutive models. One of the objectives of this project is the assessment of the uncertainties associated with nonlinear simulation of 1D site effects. A first verification phase (i.e., comparison between numerical codes on simple idealistic cases) will be followed by a validation phase, comparing the predictions of such numerical estimations with actual strongmotion recordings obtained at well-known sites. The benchmark presently involves 21 teams and 23 different computational codes. We present here the main results of the verification phase dealing with simple cases. Three different idealized soil profiles were tested over a wide range of shear strains with different input motions and different boundary conditions at the sediment/bedrock interface. A first iteration focusing on the elastic and viscoelastic cases was proved to be useful to ensure a common understanding and to identify numerical issues before pursuing the nonlinear modeling. Besides minor mistakes in the implementation of input parameters and output units, the initial discrepancies between the numerical results can be attributed to (1) different understanding of the expression “input motion” in different communities, and (2) different implementations of material damping and possible numerical energy dissipation. The second round of computations thus allowed a convergence of all teams to the Haskell–Thomson analytical solution in elastic and viscoelastic cases. For nonlinear computations, we investigate the epistemic uncertainties related only to wave propagation modeling using different nonlinear constitutive models. Such epistemic uncertainties are shown to increase with the strain level and to reach values around 0.2 (log10scale) for a peak ground acceleration of 5 m=s2at the base of the soil column, which may be reduced by almost 50% when the various constitutive models used the same shear strength and damping implementation.

Published
2016
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18. SMART 2008: Overview, synthesis and lessons learned from the International Benchmark

Author

Nicolas Bonfils, Salim Abouri, Thierry Chaudat, Benjamin Richard, François Voldoire, Paolo Martinelli, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, EDF (EDF), Structures & Simulations, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Torsion, Engineering, Earthquake engineering, Research program, Computation, 0211 other engineering and technologies, Frequency shift, 020101 civil engineering, 02 engineering and technology, Shear walls assembly, Civil engineering, International benchmark, 0201 civil engineering, Seismic analysis, [SPI]Engineering Sciences [physics], Reinforced concrete, Seismic margins, Shaking table tests, Civil and Structural Engineering, 021105 building & construction, business.industry, Probabilistic logic, Industrial engineering, Earthquake shaking table, business
Abstract

International audience; This paper reports the main results and conclusions of an International Benchmark jointly organized within the framework of a wide research program launched by the French Atomic Energy and Sustainable Energies Commission (CEA), Electricité De France (EDF) entitled ''Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effect (SMART)". This research program included first an experimental campaign on reduced scaled specimen and shaking table tests, and second, a Benchmark exercise based on the contest of numerical methods and methodologies referring to the experimental results from the tests. The objectives of the Benchmark exercise were to compare the results obtained by conventional seismic assessment methods with those obtained by best-estimate methods, to compare the methodologies of taking into account uncertainties in the numerical analyses when a probabilistic assessment should be performed and to create an event allowing the international community in earthquake engineering to discuss the aforementioned topics of common interest. According to the analysis of the results, it turned out that (a) conventional methods are clearly able to provide relevant seismic assessment at the design level; (b) when dealing with overdesign seismic loadings, advanced best-estimate methods seem to be able to capture several key indicators such as the frequency shift of the peak of the response spectra; and (c) the blind nonlinear computations demonstrate a high robustness level of the specimen based on both structural and local damage indicators (frequency shift and inter-story drift, respectively).

Published
2016
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19. Regularised crack behaviour effects on continuum modelling of quasi-brittle materials under cyclic loading

Author

Alain Millard, Maxime Vassaux, Frédéric Ragueneau, Benjamin Richard, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Laboratoire de Mécanique Systèmes et Simulation (LM2S)

Subjects
Materials science, Mechanical Phenomena, 0211 other engineering and technologies, 02 engineering and technology, [SPI.MAT]Engineering Sciences [physics]/Materials, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Crack closure, Brittleness, [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], 0203 mechanical engineering, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], medicine, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Virtual test, Cyclic loading, Shear wall, General Materials Science, cyclic loading, 021101 geological & geomatics engineering, Continuum (measurement), business.industry, Mechanical Engineering, virtual testing, [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique, Stiffness, Structural engineering, regularised stiffness recovery, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], [INFO.INFO-NA]Computer Science [cs]/Numerical Analysis [cs.NA], 020303 mechanical engineering & transports, Mechanics of Materials, hysteresis effects, concrete, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, medicine.symptom, [SPI.GCIV.MAT]Engineering Sciences [physics]/Civil Engineering/Matériaux composites et construction, business, damage, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire
Abstract

International audience; A continuum model for quasi-brittle materials able to reproduce mechanical phenomena related to cyclic loading is proposed. Specific care is taken to reproduce progressive stiffness recovery and hysteresis effects caused respectively by crack closure and friction. A virtual testing approach is set up to analyse the evolution of microscopic quantities during uni-axial cyclic tests and to justify an original and efficient modelling of these phenomena. Thus , a reg-ularised formulation of the homogenised multiple contact problem induced by the non-simultaneous closure of microscopic cracks is presented. The proposed continuum model is validated by means of member-scale simulations of reversely loaded reinforced concrete shear walls .

Published
2015
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20. SMART 2008: Shaking table tests on an asymmetrical reinforced concrete structure and seismic margins assessment

Author

Mathieu Corus, François Voldoire, Salim Abouri, Thierry Chaudat, Paolo Martinelli, Benjamin Richard, Nicolas Bonfils, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, EDF R&D (EDF R&D), EDF (EDF), EDF Septen, Dynamic and Earthquake Engineering Group, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique des Structures Industrielles Durables (LAMSID - UMR 8193), EDF (EDF)-EDF (EDF)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Structures & Simulations, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), and EDF (EDF)-EDF (EDF)

Subjects
Torsion, Engineering, media_common.quotation_subject, Shear walls assembly, Asymmetry, Seismic analysis, [SPI]Engineering Sciences [physics], medicine, Seismic margins, Geotechnical engineering, media_common, Civil and Structural Engineering, business.industry, Torsion (mechanics), Stiffness, Reinforced concrete, Shaking table tests, Structural engineering, Nonlinear system, Amplitude, Earthquake shaking table, medicine.symptom, business, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire
Abstract

International audience; The paper reports the main findings of a series of shaking table tests on a 3-story ¼-scale reinforced concrete model characterized by strong asymmetry, representative of a nuclear building. The specimen was subjected to 13 bi-directional input ground motions with increasing maximum acceleration from 0.05 to 1.0 g, which induced significant torsion and a nonlinear response. The tests were conducted on the AZALEE shaking table (Saclay, France) as part of a wide research program launched by the French Atomic Energy and Sustainable Energies Commission (CEA), Electricité De France (EDF) and the International Atomic Energy Agency (IAEA), titled, ''Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effect (SMART)." Based on the analysis of the test results, the following conclusions were drawn: (a) moderate damage occurred on the specimen (mainly close to the geometric singularities) as revealed by the crack patterns observed at the end of the seismic test sequence; (b) the model responded mainly in the torsional mode; (c) an important specimen stiffness reduction was observed with a shift of the first peak frequency almost equal to 50%; (d) the seismic margins assessment carried out with two distinct failure criteria (frequency shift and inter-story drift) showed an important specimen robustness for high seismic amplitude as well.

Published
2015
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21. Experimental and numerical study of a half-scaled reinforced concrete building equipped with thermal break components subjected to seismic loading up to severe damage state

Author

Benjamin Richard, Amandine Ma, Frédéric Ragueneau, Alberto Frau, Cédric Giry, Olivier Loiseau, Nicolas Ile, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire de Mécanique et Technologie (LMT), and École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Deformation (mechanics), business.industry, Seismic loading, Constitutive equation, 0211 other engineering and technologies, Torsion (mechanics), [SPI.MECA.VIBR]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Vibrations [physics.class-ph], 020101 civil engineering, 02 engineering and technology, Bending, Structural engineering, 0201 civil engineering, 021105 building & construction, Representative elementary volume, [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques, Earthquake shaking table, [SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures, business, [SPI.GCIV.GCN]Engineering Sciences [physics]/Civil Engineering/Génie civil nucléaire, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering, Thermal break
Abstract

A half-scaled reinforced concrete (RC) structure designed with an irregular shape to exhibit coupling torsional/bending effects and equipped with thermal break components was subjected to seismic tests. The aim of the experimental campaign was to analyze the influence of the thermal break components on the overall behavior of the mock-up in order to close the gap between the thermal and the seismic requirements in case of strongly irregular RC structures. The analysis of the experimental results is supported by experimental/numerical comparisons using an homogenized constitutive law to describe the behavior of a representative volume element (RVE) of RC. The observations show that the thermal break components do not significantly modify the dynamic behavior of the RC structure and ensure almost the full load transfer between the shearwalls and the connected slabs.

Published
2015
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22. Experimental and Numerical Investigation of Torsionally Irregular RC Shear Wall Buildings with Rutherma Breakers

Author

Frédéric Ragueneau, Stefen Scheer, Alain Le Maoult, Seref Diler, Benjamin Richard, Ahmet Yakut, Gabriela M. Atanasiu, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
[SPI]Engineering Sciences [physics], Data acquisition, Seismic tests, business.industry, Slab, Foundation (engineering), Shear wall, Earthquake shaking table, Structural engineering, Spandrel, business, Geology, Structural element
Abstract

A challenging prototype building having irregularly placed shear walls in plan has been designed and tested on the AZALEE shaking table at the TAMARIS laboratory in CEA/Saclay. The research project, called ENISTAT, was funded by the SERIES project via Transnational Access to the CEA/Saclay facility in France. The project has three main objectives: (1) Study the behaviour of the mock-up under increasing bi-directional horizontal synthetic earthquake records; (2) Attempt to evaluate the experimental results using modern experimental techniques for data acquisition; (3) Implement & monitor the performance of a new structural element that allows for wall-slab connection to reduce thermal energy losses. Rutherma elements were used only at the second floor level as a connection member between the shear walls and the slab. After initial low level tests, seismic tests having PGA’s of 0.1, 0.2, 0.4, 0.6 and 0.8 g were applied consecutively. During the first three tests, i.e. up to 0.4 g, no significant damage was observed in the structural members except minor hairline cracks on the spandrel beams. At the 0.6 g test, more cracks in beams were observed without any major crack in walls. During the 0.8 g test, separation of the shear wall member from the foundation was observed on the flexible side. No damage on the Rutherma breakers was observed.

Published
2015
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23. Estimation of Modal Properties of Low-Rise Buildings Using Ambient Excitation Measurements

Author

K. K. Wijesundara, Caterina Negulescu, Evelyne Foerster, University of Peradeniya, Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-09-RISK-0009,URBASIS,SISmologie URBAine: évaluation de la vulnérabilité et des dommages sismiques par méthodes innovantes(2009), European Project, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Damping ratio, Engineering, Article Subject, business.industry, Mechanical Engineering, Acoustics, Structural engineering, [PHYS.MECA]Physics [physics]/Mechanics [physics], Masonry, Geotechnical Engineering and Engineering Geology, Condensed Matter Physics, Displacement (vector), lcsh:QC1-999, Modal, Mechanics of Materials, Normal mode, 11. Sustainability, Time domain, business, Continuous wavelet transform, Excitation, lcsh:Physics, Civil and Structural Engineering
Abstract

International audience; Continuous wavelet transform (CWT) has recently emerged as a promising tool for identification of modal properties through ambient excitation measurements of structures. However, it is difficult to obtain an accurate estimation of damping ratio directly from time-frequency decomposition of ambient vibration measurements using CWT. The main objective of this study is to introduce a new method called two-step procedure in the estimation of damping ratios using ambient vibration measurements. The two-step procedure involves the development of random decrement (RD) signature from the ambient vibration measurements, which is equivalent to the damped free vibration response of a structure under a given initial displacement and subsequently decomposition of time domain RD signature into time-frequency domain using CWT. The secondary objective of the study is to show that CWT is capable of identifying the natural periods and mode shapes of low-rise buildings using ambient vibration measurements. Furthermore, the two-step procedure is validated with two practical applications in a five-storey reinforced concrete structure with masonry infill walls and a three-storey masonry structure. Finally, a conclusion can be drawn that the two-step procedure yields a reasonably good estimation of damping ratio.

Published
2015
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24. Contribution numérique pour l’optimisation d’un mode opératoire de soudage – Identification d’une source de chaleur équivalente

Author

Christis Z. Chrysostomou, Nicolae Taranu, Lluis Torres, Alper Ilki, Philippe Mongabure, Mehdi S. Saiidi, Mihaela Anca Ciupala, Iman Hajirasouliha, Yaser Jemaa, Nicholas Kyriakides, Yasser Helal, Kypros Pilakoutas, Maurizio Guadagnini, Mihai Budescu, Reyes Garcia, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Engineering, business.industry, Beam-Column Joints Post-Tensioned Metal Straps, Full scale, Inter-Story Drift, Building and Construction, Structural engineering, Seismic Strengthening, Geotechnical Engineering and Engineering Geology, Civil Engineering, Shaking Table Tests, Substandard RC Buildings, Beam-Column Joints, Post-Tensioned Metal Straps, [SPI]Engineering Sciences [physics], Seismic tests, Forensic engineering, Engineering and Technology, Earthquake shaking table, TH, business, Reinforcement, Strapping, Civil and Structural Engineering
Abstract

The effectiveness of a novel Post-Tensioned Metal Strapping (PTMS) technique at enhancing the seismic behavior of a substandard RC building was investigated through full-scale, shake-table tests during the EU-funded project BANDIT. The building had inadequate reinforcement detailing in columns and joints to replicate old construction practices. After the bare building was initially damaged significantly, it was repaired and strengthened with PTMS to perform additional seismic tests. The PTMS technique improved considerably the seismic performance of the tested building. While the bare building experienced critical damage at an earthquake of PGA = 0.15 g, the PTMS-strengthened building sustained a PGA = 0.35 g earthquake without compromising stability.\ud \ud

Published
2014
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25. CAST3M modelling of a spent fuel assembly bending during a handling accident Rod failure risk evaluation from the experimental results of spent fuel rod bending test

Author

Philippe Mongabure, Caroline Guerin, P. Bouffioux, Thomas Laporte, C. Vaille, C. Cappelaere, Alain Miquet, Laboratoire de Mécanique Systèmes et Simulation (LM2S), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Laboratoire d'Etudes de Mécanique Sismique (EMSI)

Subjects
0209 industrial biotechnology, Engineering, business.industry, Mechanical Engineering, Nozzle, Constitutive equation, Stiffness, 02 engineering and technology, Bending, Structural engineering, Curvature, Industrial and Manufacturing Engineering, Spent nuclear fuel, Cracking, [SPI]Engineering Sciences [physics], 020303 mechanical engineering & transports, 020901 industrial engineering & automation, 0203 mechanical engineering, medicine, General Materials Science, medicine.symptom, business, Beam (structure)
Abstract

International audience; The fuel handling operating rules exclude any accidental risk. However in the framework of the PRECCI R&D project, the bending of a spent fuel assembly resulting from its locking during a translation displacement is taken into account. This enabled us to develop an approach based on experiments and calculations that allows us to simulate the behaviour of an assembly under such loading. This study was carried out in CEA laboratories with the funding and the technical support of EDF. A three points bending test on a spent fuel rod segment was performed at the Laboratory for Mechanical Behaviour of Irradiated Materials (LCMI). From the experimental strength-displacement curve, a maximum failure strain, a maximum failure curvature and an equivalent constitutive equation were determined. CAST3M modelling of the fuel rod taking into account the elasto-plastic behaviour of the clad and the cracking of the UO2 fuel pellets was verified by the experimental results. Consequently, the identification of the respective contributions of the clad and of the pellets to the rod global behaviour was made possible. A two dimensional assembly with beam elements was modelled with CAST3M. The properties of the beams modelling the different parts of the assembly (top and bottom nozzle, grids) were chosen and adjusted according to their materials (zirconium alloys, steel) in order to obtain stiffness, tensile and shear behaviour, sliding and holding functions close to the experimental ones. Assembly bending calculations were performed. In order to obtain a rod integrity estimator, their maximum calculated strains and curvatures as a function of the bending angles can be compared to the failure experimental ones.

Published
2014
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26. A robust CRE-based approach for model updating using in situ measurements

Author

François Louf, P. í. Charbonnel, Ch. Le Noac'h, Pierre Ladevèze, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, ASTRIUM, EADS - European Aeronautic Defense and Space, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
In situ, Engineering, Constitutive equation, 02 engineering and technology, in situ measurements, Residual, Lack Of Knowledge, 01 natural sciences, [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], 0203 mechanical engineering, Model updating, Simple (abstract algebra), General Materials Science, Lack of knowledge, 0101 mathematics, Aerospace, Simulation, Civil and Structural Engineering, Series (mathematics), business.industry, Mechanical Engineering, Process (computing), Computer Science Applications, 010101 applied mathematics, 020303 mechanical engineering & transports, Modeling and Simulation, [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Mechanics of the structures [physics.class-ph], business, Algorithm, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

International audience; This paper presents a systematic approach for comparing a numerical model to test results performed in situ on a structure with time-dependent behavior. A crucial issue for an engineer is to be able to assess the quality of models, based on a series of measurements. Dealing with in situ measurements as experimental reference for model updating involves two major difficulties: the excitations can be multiple and affected by large disturbances. The validation process we propose is based on the mechanical concept of Constitutive Relation Error (CRE) and aims at reducing the Lack Of Knowledge (LOK) attached to both the excitation forces and the parameters of the numerical model. The updated values can be computed inside confidence intervals that correspond to the lower contours of the CRE-based residual to minimize. The proposed method will be illustrated with a numerical example taken from the aerospace industry and applied for correcting a simple Ariane 5 model by comparison with flight measurements.

Published
2013
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27. Experimental characterization and modeling of energy dissipation in reinforced concrete beams subjected to cyclic loading

Author

Nicolas Ile, Benjamin Richard, R. Crambuer, Frédéric Ragueneau, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Damping matrix, Computer science, business.industry, Three point bending tests, Constitutive equation, Bending, Structural engineering, Dissipation, Damping, Vibration, Reinforced concrete, Nonlinear system, [SPI]Engineering Sciences [physics], Vector field, Bouc–Wen model of hysteresis, Damage model, business, Civil and Structural Engineering, Reverse cyclic loading
Abstract

The way of modeling the damping phenomenon in nonlinear time history analysis is still an opened question and remains a motivating challenge in the scientific community. The well-known approach lies in considering non-physical viscous forces that are proportional to the velocity field. A damping matrix must be defined and its identification is not based on physical considerations. This study aims at exploring the possibility of identifying a local constitutive model in order to account for damping in a natural way. To reach this objective, an experimental campaign based on reinforced concrete beams subjected to reverse three-point bending tests is presented. These results allow identifying in an accurate way the hysteretic scheme used to take into account the hysteretic phenomenon. In particular, an ad hoc hysteretic scheme is shown to be consistent in terms of energy dissipation. Numerical free vibration tests are then carried out in order to demonstrate that the use of a viscous damping can be avoided if the local constitutive concrete model accounting for hysteretic phenomenon is accurately identified.

Published
2013
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28. A semi-active controller tuning and application to base seismically-isolated structures

Author

Sette Diop, C-S Teodorescu, Ioannis Politopoulos, Messaoud Benidir, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire des signaux et systèmes (L2S), and Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)

Subjects
0209 industrial biotechnology, State variable, Earthquake engineering, Engineering, Friction, Floor spectra, 0211 other engineering and technologies, 02 engineering and technology, Magnetorheological Dampers, Damping, Seismic protection, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Semi active, 020901 industrial engineering & automation, Control theory, Ball (mathematics), Response spectrum, 021110 strategic, defence & security studies, Structures dynamics control, Semi-active control, business.industry, Base isolation, Seismic isolation, Time limit, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Nonlinear system, business, Aseismic control
Abstract

International audience; This paper proposes a modified version of Leitmann and co-authors' classical result on the stabilization of uncertain nonlinear systems. In particular, for usual models of structure dynamics in earthquake engineering it is shown that applying a specific control law drives the state variables into a ball around the origin (arbitrarily chosen) in finite time as long as the radius of the ball is not lower than a limiting value. In addition estimates of this limiting ball radius and the time limit for arbitrary ball radius are provided. The semi-active control thus provides the control designer with interesting design parameters. It is also an attempt to explicitly use pseudoacceleration floor response spectrum as a performance criterion. Though not limited to twodegree- of-freedom structures, this semi-active control is applied to these plant models for simplicity and illustrated through simulations.

Published
2013
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29. A robust nonlinear semi-active control for base seismically-isolated structures

Author

Ioannis Politopoulos, Messaoud Benidir, Sette Diop, C.S. Teodorescu, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire des signaux et systèmes (L2S), and Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)

Subjects
0209 industrial biotechnology, Variable structure control, State variable, Engineering, Friction, Floor spectra, 0211 other engineering and technologies, Vibration control, 02 engineering and technology, Magnetorheological Dampers, Damping, Seismic protection, [SPI.AUTO]Engineering Sciences [physics]/Automatic, 020901 industrial engineering & automation, Control theory, Ball (mathematics), Active noise control, 021103 operations research, business.industry, Semi-active control, Structures dynamics control, Base isolation, Seismic isolation, Nonlinear system, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, Robust control, business, Aseismic control
Abstract

This paper proposes a robust nonlinear semi-active control for base seismically-isolated structures. The control is based upon an extension of works of Leitmann et al. on the stabilization of nonlinear systems with uncertain models. For usual models of structure dynamics it is shown that applying a specific control law drives the state variables into a ball of specified radius in finite time. The radius of the ball may be arbitrarily chosen as long as it is not lower than a limiting value. In addition, estimates of this limiting ball radius is provided. The time to reach the ball is also provided. The semi-active control thus provides the control designer with interesting design parameters. The efficacy of proposed semi-active control is illustrated by its application to simple models of structures focusing in particular to the attenuation of excitation transmitted from floor to equipment mounted on them.

Published
2013
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30. Continuum damage mechanics based model for quasi brittle materials subjected to cyclic loadings: Formulation, numerical implementation and applications

Author

Benjamin Richard, Frédéric Ragueneau, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Materials science, Tension (physics), business.industry, Mechanical Engineering, Constitutive equation, Concrete modeling, Structural engineering, Plasticity, Compression (physics), Cracking, [SPI]Engineering Sciences [physics], Brittleness, Damage mechanics, Mechanics of Materials, Hardening (metallurgy), Thermodynamics, General Materials Science, Cyclic loading, business, Nonlocal
Abstract

International audience; In this paper, a new constitutive model for quasi-brittle materials subjected to cyclic loadings is presented. The main features are the asymmetry between tension and compression, permanent strains and unilateral effect, ensuring not only the relevancy but also the reliability of numerical predictions. The hysteretic effects are also included in the model since their importance for seismic applications has been emphasized in the literature. The numerical implementation of the model is presented, and local tests are shown for validation. Reinforced concrete structures subjected to cyclic loading are considered to highlight the efficiency of the model.

Published
2013
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31. A methodology for robust updating of nonlinear structural models

Author

André Orcesi, Lucas Adelaide, Benjamin Richard, Christian Cremona, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Département Structures et Ouvrages d'Art (IFSTTAR/SOA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Paris-Est, Direction de la Recherche et de l'Innovation, and Ministère de l'Ecologie, de l'Energie, du Développement durable et de la Mer

Subjects
Engineering, STRUCTURE, 020101 civil engineering, Context (language use), 02 engineering and technology, computer.software_genre, PROPRIETE MECANIQUE, 0201 civil engineering, [PHYS.MECA.STRU]Physics [physics]/Mechanics [physics]/Structural mechanics [physics.class-ph], 0203 mechanical engineering, APPROCHE PROBABILISTE, Feature (machine learning), Reliability (statistics), Civil and Structural Engineering, Parametric statistics, Structural mechanics, business.industry, Probabilistic logic, Bayesian network, Nonlinear system, 020303 mechanical engineering & transports, MAINTENANCE, MECANIQUE, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], Data mining, business, computer
Abstract

Robust updating of parametric probabilistic models in the context of nonlinear structural mechanics represents a great challenge. A framework based on the combined use of structural reliability theory and Bayesian networks is proposed. The methodology is applied to practical engineering problems in the field of civil engineering. This approach appears as being useful to better estimate mechanical properties of an existing structure and may avoid carrying out in situ destructive tests. One of the major feature is that only in situ information available at the member scale (displacements, rotations, etc.) are required. Several structural cases are discussed to point out the main features of the methodology.

Published
2012
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32. Experimental and numerical investigation of the earthquake response of crane bridges

Author

Thierry Chaudat, Georges Nahas, Cyril Feau, George S. Kamaris, Ioannis Politopoulos, Charlie Mathey, Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire de Mécanique et Technologie (LMT), and École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Engineering, Work (thermodynamics), Similarity (geometry), business.industry, Structural engineering, Overhead crane, Degrees of freedom (mechanics), Bridge (nautical), [SPI]Engineering Sciences [physics], TA, Earthquake shaking table, business, Scale model, Beam (structure), ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering
Abstract

International audience; The experimental and numerical response of crane bridges is studied in this work. To this end, an experimental campaign on a scale model of an overhead crane bridge was carried out on the shaking table of CEA/Saclay in France. A special similarity law has been used which preserves the ratios of seismic forces to friction forces and of seismic forces to gravity forces, without added masses. A numerical model, composed of beam elements, which takes into account non-linear effects, especially impact and friction, and simulates the earthquake response of the crane bridge, is presented. The comparison of experimental and analytical results gives an overall satisfactory agreement. Finally, a simplified model of the crane bridge, with only a few degrees of freedom is proposed.

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33. Experimental validation of an anisotropic delay damage model for impact on reinforced concrete structures

Author

Marion Chambart, Rodrigue Desmorat, Fabrice Gatuingt, Daniel Guilbaud, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etudes de Mécanique Sismique (EMSI), Service d'Etudes Mécaniques et Thermiques (SEMT), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Modélisation des Systèmes et Structures (DM2S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, autre, and AUTRES

Subjects
Digital image correlation, Materials science, business.industry, Isotropy, 02 engineering and technology, Structural engineering, Plasticity, 021001 nanoscience & nanotechnology, [SPI.GCIV]Engineering Sciences [physics]/Civil Engineering, 020303 mechanical engineering & transports, 0203 mechanical engineering, Flexural strength, Reinforced solid, Dynamic loading, [SPI.GCIV.DV]Engineering Sciences [physics]/Civil Engineering/Dynamique, vibrations, 0210 nano-technology, business, Failure mode and effects analysis, Beam (structure)
Abstract

International audience; Impact problems on reinforced concrete structures are usually computed with models coupling plasticity and isotropic damage. The induced damage anisotropy observed for quasi-brittle materials such as concrete is often reproduced considering different variables for tension and compression (not consistent with the thermodynamic framework). Introducing viscosity for both damage and plasticity evolutions enables to reproduce the strength enhancement due to rate effects. Such kinds of models present the main advantage to describe precisely each phenomenon locally observed (different rate effects in traction and compression, compaction under confined loadings ...) but require a large number of parameters. Anisotropic damage is quite relevant to describe the micro-cracking pattern and the failure conditions of quasi-brittle materials and structures. In concrete, a state of micro-cracks orthogonal to the loading direction in tension and parallel to it in compression is easily described by a second order damage variable. This anisotropic delay-damage model, used in this work, introduces only few parameters (7 including elasticity parameters E and ν) compared to the ones mentioned higher. The efficiency and the validation of such an approach is illustrated with its application on impacted reinforced concrete beams and dynamic Brazilian tests. The test has been performed with the drop-weight tower ORION of the CEA Saclay for two kinds of beam geometries in order to exhibit flexion and shear rupture. 1 INTRODUCTION The challenge of understanding the behavior of civil engineering structures under dynamic loading is usually linked to security issues but also some economic problems. Advances in instrumentation continue to improve our understanding on these subjects, so one continues around the world to develop impact tests on reinforced concrete structures. The civil engineering is one area where the tests are the most numerous. Indeed, it's only repeating the experiments and varying the parameters that we managed to understand the behavior of structures. But few cases where experiments are conducted on real structures with the stresses actually envisaged, are available. Moreover these experiments do not always provide more information than mockup models. Therefore, we find in the literature a large number of tests on simple structures such as slabs or beams. The philosophy of these kind of tests is to demonstrate on simple structures (beams, slabs) a number of local and global phenomena to allow modeling of more complex cases. Tests developed in the Dynamics Laboratory (DYN) of the CEA Saclay during this work include in this perspective. Two types of tests on a drop-weight tower were made: dynamic Brazilian tests and impact tests on beams. The dynamic Brazilian tests are relatively uncommon in the literature ((Tedesco, Ross, and Kuennen 1993) made the first dynamic Brazilian tests on split Hopkinson bars), but very interesting. A fast digital camera has been used in addition to more traditional, but precise and efficient, instrumentations (accelerometer, displacement measurement by camera, force sensors). The recorded images are analyzed by Digital Image Correlation with the software CORRELI developed at the LMT Cachan (Besnard, Hild, and Roux 2006). The impact tests on beams were designed to study the transition from a ductile failure mode (flexural) to a brittle fracture mode (shear cone). The two factors influencing this study are the slenderness of the beam and the transverse reinforcement (stirrups). An anisotropic delay-damage model has been developed during this work and it is presented in the last section. Finally this model is used to model the tests realized on the drop-weight tower.

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