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Summary: A complex variable solution is derived for the ground movements around a tunnel considering the lining at different positions in the drilled hole in a linear elastic half‐plane. The soil displacements for three different convergence patterns are presented and compared. It is shown that the surface settlement trough will become flatter and wider when the lining moves upwards; the horizontal displacements are more concentrated in the region below the lining; and the region influenced by displacements is wider. Most calculated settlement troughs can be well represented by Gaussian curves with simple parameters, but the obtained width parameters are larger than the traditional empirical values. The rigorous solution can be used as a simple tool to understand the fundamental mechanism of the lining buoyancy problem and as a benchmark for numerical procedures based on more sophisticated models. The importance of buoyancy effect on the displacement field should be taken into account. [ABSTRACT FROM AUTHOR]

For the seismic design of a structure, horizontal ground shaking is usually considered in two perpendicular directions, even though real horizontal ground motions are complex two-dimensional phenomena that impose different demands at different orientations. While the issue of ground motion dependence on the orientation of the recording devices has been the focus of many significant developments during the last decade, the effects of directionality on the characteristics of the structure have received less attention. This work presents a proposal to calculate the probability of exceedance of elastic spectral displacements accounting for structural typology and illustrates its relevance by means of its application to two case-study buildings. In order to ease its implementation in seismic design codes, a simplification is developed by means of a detailed statistical analysis of the results obtained using four sets of real hazard curves. The framework presented herein is considered to represent an important contribution to the field of performance-based earthquake engineering, permitting improved treatment of directionality effects within seismic risk design and assessment. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An equilibrium problem for an elastic body is considered. It is assumed that the body has a thin elastic inclusion and a thin rigid inclusion. We analyze a junction problem assuming that the inclusions have a joint point. Different equivalent problem formulations are discussed, and existence of solutions is proved. A set of junction conditions is found. We investigate a convergence to infinity and to zero of a rigidity parameter of the elastic inclusion. A delamination of the elastic inclusion is also investigated. In this case, inequality-type boundary conditions are imposed at the crack faces to prevent a mutual penetration between crack faces. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article discusses the optimum design parameters of superelastic-friction base isolator (S-FBI) for seismic protection of highway bridges against near-field earthquakes. It states that base isolation system utilizes sliding bearing and shape memory alloy (SMA) device for passive structural control. It mentions the use of nonlinear time-history analyses to assess the effects of various design parameters including natural period of isolated bridge, yield displacement of SMA device, and the friction coefficient of sliding bearings, and that temperature effect for SMA's superelasticity is investigated. It shows that S-FBI system is an effective means in mitigating the response of highway bridges under near-field earthquakes while temperature has significant effect in SMA's superelasticity.

In general, internal cells are required to solve elastic problems with a centrifugal load in non-homogeneous materials using a conventional boundary element method (BEM). However, in this case, the merit of the BEM, which is the ease of data preparation, is lost. In this study, it is shown that two-dimensional elastic problems with centrifugal load in non-homogeneous materials with variable mass density can be solved without the use of internal cells using the triple-reciprocity BEM. A body force distribution is interpolated using boundary integral equations. A new computer program is developed and applied to solve several problems. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We test the performance of a three-dimensional finite element, named HC3 , which generalizes the high-continuity (HC) finite element proposed by Aristodemo in 1985 for two-dimensional elastic problems. The HC3 finite element is based on a quadratic B-spline interpolation of the displacement field in three-dimensional linear elasticity. The main feature of this interpolation technique, which can be considered as a particular case of the Bézier interpolation, consists in its capability in reproducing displacement fields of 𝒞1 smoothness with a computational cost equivalent to a linear interpolation, i.e. with a single knot for each element. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this article, a particular off-center bracing system is introduced. In this system, the tensile diagonal strut is not straight. When the load is applied, the original geometry changes and thus causes the system to harden. Based on this behavior, a step-by-step analytical method is developed. Using this method, a Geometrically Nonlinear Analysis Program (GNAP) is designed to analyze the elastic force-displacement relation. Extension of this program to dynamic analysis led to a Dynamic Nonlinear Analysis Program (DNAP). The object of this article is to show that such bracing systems will lead to less seismic force on such structures compared to classic concentric bracing systems. On the other hand, it will be shown that the bracing system causes semi-uncoupling of structure, and that the probable excursions in the nonlinear range during severe earthquakes will not cause significant deterioration in its strength and stiffness. [ABSTRACT FROM AUTHOR]

The calculation of the derivatives of the state variables with respect to material parameters using the direct differentiation method is developed for the case of a finite strain finite element analysis in corotational formulation for material behaviour including hypo-elasticity and non-linear isotropic and kinematic hardening plasticity. The sensitivity analysis for the case of flexible-to-flexible contact, required in indentation testing, has been included. The derivatives obtained in a rotating-stretching bar problem are compared to results obtained by the finite difference method in order to verify the suitability of the corotational formulation in sensitivity analysis for dealing with rigid body rotations. Material parameter identification using a gradient-based numerical optimization procedure is assessed with respect to stability by using pseudo-experimental indentation curves, obtained from modelling with known material parameters, and superposed with artificial noise. The effect of the load history on parameter identification is investigated. [ABSTRACT FROM AUTHOR]

The general theory of linearized elasticity with eigenstrain is considered with applications to continuous, discrete and discretized structures. It is shown that any eigenstrain can be uniquely decomposed into impotent and nilpotent constituents. The proven theorem on decomposition is based on the concepts of functional analysis, in particular, with respect to Hilbert functional spaces. This unique decomposition allows for the individual and independent control of stress, strain and displacement (e.g. shape control). The associated algorithm avoids the cumbersome solution of boundary-value problems with eigenstrain in connection with these control problems. Decomposition of eigenstrain opens the practically important opportunity to fully separate the control of strain and stress produced by force loading. [ABSTRACT FROM AUTHOR]

A cohesive damage zone model is presented for a circular crack in a quasi-brittle material. Analytical expressions are derived for the size of the cohesive zone, the opening displacement under loading and the residual displacement after unloading. [ABSTRACT FROM AUTHOR]

Presents a study which evaluated the transverse strain of hyperelastic solids as a function of its longitudinal using a constitutive equation for compressible hyperelastic materials. Presentation of the equations; Strain energy function and stresses for hyperelastic materials; Application to compressible rubber-like materials under simple tension and/or compression conditions.

Focuses on study which investigated the characteristics of the elastic modulus of polymeric coatings, other bulk materials and the capabilities of the dynamic mechanical analyzer (DMA) used. Reason that the measurement of coating mechanical properties is important; Information on the DMA 7e which is controlled with the Pyris Series software; How the DMA indentations were compared with those from the Hystitron Tribscope, a nanoindentation instrument.

Pure AISI 316L steel is investigated after solution heat treatment (1050 °C/H2O) and structural sensitization (650 °C). Two quite different intergranular corrosion tests are used to determine the degree of structural sensitization due to the precipitation of secondary phases along the grain boundaries (mainly the M23C6 and σ-phase): the oxalic acid etch test and the electrochemical potentio-kinetic reactivation test. Generally, the dissolution of chromium-rich carbides (M23C6) is provoked by oxalic acid etch tests, whereas the chromium-depleted zones, in the vicinity of chromium-rich carbides (M23C6), are attacked by electrochemical potentio-kinetic reactivation tests. Both intergranular corrosion tests are used to determine the maximum degree of structural sensitization. Thus structural analysis by carbon replicas reveals the Laves phase, and both the M23C6 and (Cr,Mo) x(Fe,Ni) y phases. The results of intergranular corrosion tests are related to the findings of the structural analysis. [ABSTRACT FROM AUTHOR]

The aim of the work is to make a comparison between the European and Japanese approaches to design Seismic‐Resistant Steel Frames (MRFs) in high seismicity areas. Therefore, the design rules for both the seismic codes are analyzed and compared. These design rules are applied to design a benchmark structure in DC3 ductility class (according to the new prEN1998) and following the Route 3 procedure (according to the Building Standard Law in Japan, BSL). The examined structural typology is a Spatial Moment Resisting Frames with regularity in plan and elevation configuration. The Japanese approach is divided in two stages. The first one regards the Allowable Stress Design (Elastic analysis) in which all the parts of the structure must be kept elastic; service and damage limitation requirements are in demand. The second stage regards the Ultimate Strength Design (Plastic Analysis) in which no‐collapse requirement and the protection of the human life are in demand. The seismic performance of the designed structures is evaluated by means of pushover analyses. [ABSTRACT FROM AUTHOR]

A new, Eurocode‐compliant design approach based on the Direct Strength Method (DSM) combined with EN 1993‐1‐3 was developed for the design of thin‐walled cold‐formed steel sections. The new design approach transfers cross‐sectional resistance according to DSM, based on numerical elastic buckling analyses on the gross cross‐section, into the global stability check according to EN 1993‐1‐3. Experimental investigations on various perforated and unperforated cold‐formed sections in compression and bending serve to verify the new design approach. In addition, a numerical model was developed, it was calibrated on the test results and used for further parametric analyses on the load‐carrying capacity of cold‐formed sections. [ABSTRACT FROM AUTHOR]