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The need for affordable housing in developing countries requires the development and use of new structural systems that allow easy, fast, and cheap construction while providing a sufficient seismic performance to protect the life and belongings of the population. In this regard, structural wall systems based on ferrocement have proved to be a feasible option to meet these criteria. Ferrocement is a construction system composed of mortar (i.e., cement, sand, and water) and thin and closely spaced steel reinforcement (i.e., small rebars, welded mesh, hexagonal wire mesh, metal fibers, etc.). This dataset corresponds to the hysteretic response of a ferrocement wall subjected to an increasing in-plane fully-reversed cyclic load test, following the loading protocol given by the ASTM Standard E2126-11. The dataset is composed of the forces and displacements read at the top section of the wall specimen. Finally, a nonlinear finite element model of the ferrocement wall, developed using SeismoStruct software, is also included along with the equivalent numerical simulation of the experimental test. This dataset can be potentially used for the calibration of hysteretic models with high pinching levels and the structural identification of ferrocement walls.

Introduction: Autoclaved Aerated Concrete (AAC) is a lightweight and energy‐efficient material which makes it one of the most convenient materials to be used in infill walls. Accordingly, AAC walls are becoming more and more favored infill systems in earthquake‐prone regions. Although the infills are not considered primary components in seismic design, they are highly susceptible to be damaged under seismic actions in in‐plane (IP) and out‐of‐plane (OOP) directions. Objective: Past post‐earthquake site surveys indicated that the failure of infill walls may result in severe casualties, injuries, and economic losses. In addition, damage to infills may hinder the functionality of critical buildings, which are expected to be in service after earthquakes. The application of horizontal bed‐joint reinforcement between infill courses is one of the promising solutions to increase the seismic resilience of infill walls. Methodology: This paper presents the experimental performance investigation of AAC infill walls with flat‐truss bed‐joint reinforcement being subjected to lateral loading in IP and OOP directions. The specimens represent relatively thin infills with a thickness of 150 mm, which are generally used in indoor environments. To consider the seismic actions in the IP direction, two full‐scale infill wall specimens (one unreinforced reference and one with flat‐truss reinforcement) built in reinforced concrete frames were first tested under reversed cyclic IP displacement reversals and then tested under the cyclic OOP displacements. Conclusions: The results revealed that the use of flat‐truss reinforcement enhanced the OOP strength, ultimate displacement, and energy dissipation capacity of infill walls that have been subjected to cyclic IP displacements previously. [ABSTRACT FROM AUTHOR]

This work presents a comprehensive strategy for analysing the complex seismic response of five Italian historical URM buildings, corresponding to different periods until 1920s. One distinctive feature of historical buildings is the need for integrating global modelling and local response of structural portions, due to possible activation of local failure modes interacting with the overall dynamic building response. Global behaviour is analysed via pushover and dynamic analyses of 3D equivalent-frame models. An original approach is adopted for assessing local out-of-plane mechanisms, accounting for their dynamic response to input time histories, filtered by the global response of the 3D model. [ABSTRACT FROM AUTHOR]

This paper presents detailed experimental and analytical investigations into the influence of textile-reinforced mortar (TRM) strengthening on the in-plane and out-of-plane response of unreinforced heritage masonry (URM) elements. The URM wall elements consist of hydraulic lime mortar and fired-clay bricks, and the TRM reinforcement employs mortar-embedded layers of alkali age-resistant glass meshes. Apart from the material characterisation tests on mortars, bricks, and TRM coupons, the experimental programme includes axial compression tests on wallettes, diagonal compression tests on square panels, as well as four-point bending tests on rectangular panels. In the latter, the bending loads are applied either parallel or perpendicular to the bed joints in order to assess the joint layout effect on the behaviour. With the aid of digital image correlation, the in-plane and out-of-plane enhancement in stiffness, strength, and ductility of the masonry elements due to the TRM strengthening is quantified, while the TRM influence on the crack patterns and failure modes is also examined. The results show that the number of mesh layers has a significant influence on the behaviour for the out-of-plane bending tests but plays a less pronounced role in the in-plane shear cases. Modified analytical models for the in-plane shear and out-of-plane bending capacities of reinforced masonry elements, of the type examined in this study, are also proposed and assessed alongside existing codified procedures. The application of current code provisions results in overly conservative estimates. In contrast, the proposed analytical approaches for determining the in-plane and out-of-plane strength provide close prediction of the experimental capacities from this study as well as those from a wider collated database of previous tests, and are therefore suitable for implementation in practical assessment and rehabilitation guidelines. • Experimental assessments for TRM strengthened masonry elements are presented. • Heritage masonry with fired-clay bricks and hydraulic lime mortar is considered. • Masonry elements with and without glass textile reinforced mortar layers are tested. • In-plane shear and out-of-plane bending tests as well as material tests are reported. • The stiffness, strength, and ductility of TRM masonry elements are quantified. • Improved analytical models for the in- and out-of-plane capacities are proposed. [ABSTRACT FROM AUTHOR]

Curved beams are used so much in the arches and railway bridges and equipments for amusement parks. There are few reports about the curved beam with the effects of both the shear deformation and rotary inertias. In this paper, a new finite element model investigates to analyze In-Plane vibration of a curved Timoshenko beam. The Stiffness and mass matrices of the curved beam element was obtained from the force-displacement relations and the kinetic energy equations, respectively. Assembly of the elemental property matrices is simple and without need to transformation matrix because of using the local polar coordinate system. The natural frequencies of curved Euler-Bernoulli beam with large thickness are not sufficiently accurate. In this case, using the curved Timoshenko beam element is necessary. Moreover, the influence of vibration absorber is discussed on the natural frequencies of the curved beam.

• The axisymmetric and in-plane transient dynamic responses of poroelastic media are investigated. • The extended precise integration method and the integral transform theorem are applied to obtain the solution. • Various suddenly applied load forms in different coordinates are involved in the transient analysis. • Effect of transversely isotropic parameters on the dynamic behavior is discussed. Based on the integral transform theorem and the extended precise integration method (EPIM), this paper investigates the axisymmetric and in-plane transient dynamic responses of multilayered transversely isotropic (TI) poroelastic media. First, the governing equations are transformed into ordinary differential equations by virtue of the integral transform technique. It can be found that the transformed equations of the axisymmetric problem are similar to those of the in-plane problem. Then, we introduce the boundary conditions and apply the EPIM to obtain the transient dynamic solution in the transformed domain. The actual solution is further gotten by the numerical transform inversion. Various suddenly applied load forms are considered in this work, including concentrated point loads, line loads, uniform strip loads and circular loads. Several numerical examples are provided to verify the proposed theory and to investigate the differences of the transient problems in cylindrical coordinates and Cartesian coordinates. The influences of transverse isotropy and load forms on transient behaviors are also analyzed. [ABSTRACT FROM AUTHOR]

The material and structural performance of calcium silicate (CS) brick masonry has received relatively little attention in the past, although this material is often used for the construction of low-rise buildings in Central and Northern Europe. Upon the occurrence of induced seismicity in the north of the Netherlands, an extensive testing programme has been conducted since 2014 at Delft University of Technology. The paper presents the outcomes of eight quasi-static cyclic tests performed within this program on CS brick masonry walls under vertical and lateral in-plane loads. Different dimensions, boundary conditions and applied pre-compression loads were considered. Overall, the tests allowed to characterise the in-plane behaviour of CS brick masonry walls. The results confirmed the influence of the shear ratio (i.e. the ratio between the effective height and the length of the wall) on the wall response in terms of prevailing failure mode, initial stiffness, force and deformation capacity, energy dissipation. Besides, the experimental outcomes stressed the difficulty in estimating the effective stiffness and near collapse drift capacity. Additionally, an empirical equation is proposed to predict the peak lateral force. The equation, calibrated against the tests presented in this paper, was validated against an extended dataset of tests performed on CS masonry walls. The equation, which does not need any input of material parameters and is applicable irrespectively of the expected failure mode, can be used to estimate the force capacity of CS masonry walls when no or limited data on the material properties are available. [ABSTRACT FROM AUTHOR]

Significant advances in the field of innovative solutions for the seismic retrofit of existing buildings can be made by coordinating experimental testing with the development of reliable numerical models. In this work, numerical models based on the Distinct Element Method are employed to simulate the in-plane lateral response of unreinforced masonry piers strengthened with a novel retrofit solution consisting of modular steel frames fastened to the external surface of masonry walls. All masonry in-plane failure mechanisms as well as the contribution of the retrofit system are explicitly included in the modeling strategy. The developed numerical models, validated on available experimental data, are employed to achieve a comprehensive insight into the performance benefits of the proposed retrofit solution, numerically accounting for different masonry typologies, vertical overburden stresses, and pier aspect ratios, as well as alternative retrofit layouts and detailing. Time, size and mass scaling, and dynamic relaxation procedures, combined with the use of monotonic loading schemes, provided a significant reduction of computational effort, enabling the parametric study to be carried out in a reasonable amount of time. Overall, the results quantify the performance benefits of the investigated retrofit method, with particularly noticeable improvements in pier drift ratio capacities. The achieved outcomes serve as a benchmark for the development of design guidelines, facilitating the proper assessment of the retrofit contribution in real-practice applications. • The in-plane performance of a steel retrofit solution for URM buildings is studied. • Numerical models based on DEM are built and validated against experimental data. • A parametric study is performed on a set of in-plane loaded masonry piers. • Masonry typology, pier length, vertical load and retrofit details are addressed. • A set of metrics is employed to assess the benefits provided by the retrofit. [ABSTRACT FROM AUTHOR]

The need for affordable housing in developing countries requires the development and use of new structural systems that allow easy, fast, and cheap construction while providing a sufficient seismic performance to protect the life and belongings of the population. In this regard, structural wall systems based on ferrocement have proved to be a feasible option to meet these criteria. Ferrocement is a construction system composed of mortar (i.e., cement, sand, and water) and thin and closely spaced steel reinforcement (i.e., small rebars, welded mesh, hexagonal wire mesh, metal fibers, etc.). This dataset corresponds to the hysteretic response of a ferrocement wall subjected to an increasing in-plane fully-reversed cyclic load test, following the loading protocol given by the ASTM Standard E2126-11. The dataset is composed of the forces and displacements read at the top section of the wall specimen. Finally, a nonlinear finite element model of the ferrocement wall, developed using SeismoStruct software, is also included along with the equivalent numerical simulation of the experimental test. This dataset can be potentially used for the calibration of hysteretic models with high pinching levels and the structural identification of ferrocement walls., (© 2024 The Authors.)

• Nine one-bay-one-story frames were tested under reversed cyclic lateral displacement excursions. • The combined in-plane and out-of-plane response of AAC infilled frames were investigated. • The in-plane drift capacity were found to be significantly reduced by the out-of-plane loads. • A new system was tested to eliminate the interaction between the frame and AAC infill walls. Performance of infill walls in reinforced concrete (RC) frames is generally questionable under the combined action of in-plane and out-of-plane seismic demands. Despite the vast number of tests investigating the behavior of brick masonry infill walls in RC frames, past research is limited for infill walls made of Autoclaved Aerated Concrete (AAC) blocks. In the first part of the study, six single-bay single-story half-scaled RC frames were tested under the action of in-plane cyclic displacement excursions and/or out-of-plane pressure. It was found that the presence of out-of-plane pressure can significantly reduce the deformation capacity of RC framed AAC infill walls. Afterwards, a new innovative system is proposed to protect the infill walls from in-plane induced forces while providing out-of-plane support. Sliding connectors placed inside the AAC blocks were used to isolate the infill wall from earthquake-induced frame deformations, while providing out-of-plane support. In order to test the beneficial effect of the proposed system, three additional tests were conducted. The proposed system managed to reach in-plane deformation demand of 2% without cracking and preserving its out-of-plane stability. [ABSTRACT FROM AUTHOR]

Highlights • Development of an innovative masonry infill system with sliding joints. • In-plane cyclic tests on full-scale RC infilled frames with solid panel and with opening. • Interpretation of the in-plane seismic experimental performance. • Comparison between the proposed innovative and a traditional infill solution. • Very promising results on the in-plane seismic performance of the proposed system. Abstract Within the European FP7 Project "INSYSME", a new seismic-resistant clay masonry infill system was conceived with the purpose of controlling damage in the masonry and reducing detrimental effects of the panel-frame interaction, through a combined use of sliding joints inserted in the masonry and deformable joints at the wall-frame interface. Although the idea behind the proposed solution stems from principles already implemented in the past, the originality of this work lies in the innovative development of the materials and of the construction details of the components. In order to assess the seismic performance of this new system, in-plane cyclic tests on one-storey one-bay RC frames with two different infill configurations (one solid and one with a central opening) have been performed within the framework of a wider experimental campaign and are discussed here. These in-plane test results have proved the ability of the proposed solution in limiting the level of damage along with the attainment of a wide margin towards the life safety requirements in comparison with traditional infill systems. Although design and construction optimization of the solution still needs to be further implemented, the results of the in-plane tests appear very promising about its use as an efficient seismic resistant non-structural component in RC buildings. [ABSTRACT FROM AUTHOR]

This paper proposes a practice-oriented platform for numerical simulation of Unreinforced Masonry (URM) buildings. It is based on introducing a new two-dimensional discrete model compatible with most existing structural analysis softwares. The proposed platform comprises of two individual two-dimensional macro-elements, a basic macro-element for modeling the piers and spandrels and a rigid-interface macro-element for modeling the nodal regions. A complete set of constitutive equations and behavioral specifications is proportionally characterized and discussed for the basic macro-element based on its phenomenology and the past experimental studies. The proposed approach provides a rather simple and efficient platform for linear or nonlinear static and dynamic analyses by considering the in-plane behavior of the URM panels. The validation of the proposed analytical platform is conducted using the results of the past experimental tests on a considerable number of piers, spandrels and a perforated wall. The comparisons indicate that the predicted failure mode and hysteretic behavior as well as the ultimate strength and displacement capacity of these specimens are in a satisfactory agreement. In particular, derivation and interpretation of the results in the proposed approach are straightforward and simple; hence, engineers can use this approach for seismic design or retrofit studies. The proposed platform can be further developed and effectively used for modeling a large building or numerous buildings. [ABSTRACT FROM AUTHOR]

Eight half-scale brick masonry walls were tested to study two important aspects of confined masonry (CM) walls related to its seismic behavior under in-plane and out-of-plane loads. Four solid wall specimens tested to investigate the role of type of interface between the masonry and tie-columns, such as toothing varying from none to every course. The other four specimens with openings were tested to study the effectiveness of various strengthening options around opening to mitigate their negative influence. In the set of four walls, one wall was infilled frame while the other three were CM walls of different configurations. The experimental results were further used to determine the accuracy of various existing models in predicting the in-plane response quantities of CM walls. Confined masonry walls maintained structural integrity even when severely damaged and performed much better than infill frames. No significant effect of toothing details was noticed although toothing at every brick course was preferred for better post-peak response. For perforated walls, provision of vertical elements along with continuous horizontal bands around openings was more effective in improving the overall response. Several empirical and semi-empirical equations are available to estimate the lateral strength and stiffness of CM walls, but those including the contribution of longitudinal reinforcement in tie-columns provided better predictions. The available equations along with reduction factors proposed for infills could not provide good estimates of strength and stiffness for perforated CM walls. However, recently proposed relations correlating strength/stiffness with the degree of confinement provided reasonable predictions for all wall specimens. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper deals with the in-plane dynamics of Horizontally Curved Beams (HCBs) supported by a visco-elastic foundation under the excitation induced by a moving mass. What has been included as worthy of detailed exposition is the inevitable contribution of the inertial actions of the mass object into the problem formulation. By taking into account the effect of Coriolis acceleration, centrifugal force and rotary inertia, the governing coupled non-linear differential equations of equilibrium for a simply supported HCB are derived. In the proposed solution, a new system of linear ordinary differential equations is distilled from the governing differential equations of motion, which can be solved utilizing standard numerical techniques. The capability as well as the reliability of the proposed semi-analytical solution is also examined through an extensive parametric study. On that account, non-dimensional parameters are defined to advantage as input data in response calculations and to better interpret the outcomes. To this aim, the Dynamic Amplification Factor (DAF) spectra are introduced with particular attention to the influential parameters such as subtended (central) angle and radius of the HCB, mass and speed of the moving object along with the number of contributing modes. The significance of allowing for the contribution of moving mass inertia is demonstrated in the dynamic response of HCBs, focusing on highly curved elements under the action of a heavy mass at high speeds. It is shown that, in a wide range of design parameters, the simplified moving-force solution would not work to satisfaction if utilized in the analysis of HCB-moving mass dynamics. However, the moving mass framework takes care of all the essential effects induced due to a moving object running on an HCB. In addition, on the basis of the multiple nonlinear regression analysis, simplified expressions have been established which are advantageous in that they supply a means to predict the DAFs in a more practical manner. The findings of the present investigation imply that the influence of additional inertial terms is of fundamental importance in a wide range of design parameters. Therefore, emphasis is placed on implementing the moving mass method, as a more rigorous and reliable representative of the real-world dynamic response of HCBs in comparison with the unsafe results obtained from the moving force approach. Attention is also accorded to the influence of cross-ties in conjunction with the torsional stiffness of rail-tie connection on the in-plane dynamics of HCBs. Also, the results indicate that sharply-curved HCBs, especially at high velocities, are apt to higher DAFs under the action of an in-plane moving inertial load. [ABSTRACT FROM AUTHOR]

This study focuses on the evaluation of seismic safety of unreinforced masonry buildings in Turkey by using fragility curves generated for two behavior modes of load bearing walls: in-plane and out-of-plane. During generation of fragility curves, a force-based approach has been used. There exist two limit states in terms of base shear strength for in-plane behavior mode and flexural strength for out-of-plane behavior mode. To assess the seismic vulnerability of unreinforced masonry buildings in Turkey, fragility curves generated for in-plane behavior were verified by the observed damage during the 1995 Dinar (Turkey) earthquake and fragility curves generated for out-of-plane behavior were verified by the observed damage during the 2010 Elazığ (Turkey) earthquake. The verification results reveal that the proposed fragility-based procedure can provide an alternative for the seismic safety evaluation of unreinforced masonry buildings in Turkey. Using this procedure, it becomes possible to investigate a large population of masonry buildings located in regions of high seismic risk in a short period of time. The obtained results are valuable in the sense that they can be used as a database during the development of strategies for pre-earthquake planning and risk mitigation for earthquake prone regions of Turkey. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the formulation and validation of a macroelement capable of simulating the in-plane response of unreinforced masonry (URM) piers and spandrels. The modeling approach adopted was originally developed for the in-plane analysis of reinforced concrete walls in the 1980s, and involves placing nonlinear shear springs in series with rotational springs to simulate both shear and flexure response. For this study, the modeling approach was extended to explicitly address the in-plane failure modes unique to URM. Specifically, the proposed macroelement includes an axial spring, three shear springs, and two rotational springs to simulate the axial, bed joint sliding, diagonal tension, and rocking/toe crushing failure modes observed during past URM pier tests. The validation of this macroelement involved comparison with 21 past experimental studies of URM pier behavior, and focused primarily on ultimate strength and failure mode simulation. Overall the macroelement properly simulated 67% of the reported failure modes and provided strength estimates with an average absolute error of 19.1%. These errors are primarily attributed to the variability of URM response as well as the uncertainty associated with using default material properties in the absence of reported material properties. Following the ‘calibration’ of the default diagonal tension strength of masonry, the average absolute error was reduced to 11.9%; however, the number of failure modes predicted remained unchanged. Finally, the proposed macroelement was used to carry out parametric studies of vertical stress, aspect ratio, and boundary conditions. [Copyright &y& Elsevier]

The paper describes the derivation of fragility curves useful for the seismic risk analyses of existing unreinforced masonry buildings inserted in aggregate. The L-shaped examined aggregate consists of three adjacent structural units that may mutually interact during seismic events. The seismic assessment is focused on the corner unit. The effects of different connection types between the adjacent units on the structural response were investigated. The seismic vulnerability of the masonry aggregate was assessed through nonlinear dynamic analyses (NDA) performed according to the multi-stripes approach. Both the in-plane and out-of-plane mechanisms were analyzed. The in-plane response of the corner unit is assessed through a 3D equivalent frame model of the entire aggregate, while the evaluation of its out-of-plane response makes use of the rigid-block assumption. Although evaluated in a separate way, the NDAs performed on the latter are based on the time histories derived from the global 3D model. The results are then processed in order to derive fragility curves, firstly, of the single failure mechanisms and, then, of the overall combined behavior. To this aim, various performance conditions are examined. For the reference building, the damage limit state is mainly governed by the in-plane behavior, while the collapse limit state by out-of-plane mechanisms. Moreover, the higher the connection level between adjacent structural units, the higher the interaction between in-plane and out-of-plane mechanisms at the collapse limit state. • Procedure for derivation of fragility curves by NLDA accounting for both in-plane and out-of-plane mechanisms. • The 3D equivalent frame model of the aggregate considers the interaction between buildings by proper joints. • Rigid block NLDAs of the OOP response use time histories derived from the 3D model of the aggregate. • For the corner building, damage limit state is governed by IP response while collapse by OOP mechanisms. • The higher the connection between structural units, the higher the interaction of IP and OOP at collapse. [ABSTRACT FROM AUTHOR]

Bio-inspired self-similar hierarchical honeycombs are multifunctional cellular topologies used for resisting various loadings. However, the crushing behavior under large plastic deformation is still unknown. This paper investigates the in-plane compressive response of selective laser melting (SLM) fabricated hierarchical honeycombs. The effects of hierarchical order, relative density as well as constituent material are evaluated. The results show that at small deformation, the AlSi10Mg alloy hierarchical honeycombs show great advantages over the elastic modulus and compressive strength than 316L steel hierarchical honeycombs. As the relative density and hierarchical order increase, the failure mechanism of AlSi10Mg alloy honeycombs gradually changes from a bending-dominated mode to a fracture-dominated mode; whereas all the 316L steel honeycombs fail due to the distortion of original unit cells. At large deformation, the AlSi10Mg alloy honeycombs behave with brittle responses, while the 316L steel honeycombs exhibit ductile responses, showing a negative Poisson's ratio behavior and gradient deformation of hierarchical unit cells. The addition of unit cell refinements improves the elastic modulus of AlSi10Mg alloy honeycombs and advances the densification of 316L steel honeycombs. In addition, the effect of constituent material on the compressive response of hierarchical honeycombs has been discussed. This study facilitates the development and future potential application of multifunctional ultra-light sandwich structures. [ABSTRACT FROM AUTHOR]