Self-centric cyclic resistance of reinforced concrete shear wall with Shape Memory Alloy: Numerical and experimental large-scale model

Abstract

Over several decades, numerous researches have been routed to forge ahead in enhancing the building performance against dynamic loads. Nowadays, smart materials such as Shape Memory Alloy (SMA) have found profound impact in many applications of civil engineering. Nickel titanium alloy (NiTi) is one of the most famous among types of SMA. The current paper studies the behavior of shear wall, representing one of the most efficient lateral bracing element, structured by NiTi subjected to cyclic loading. Due to the unique characteristics of NiTi particularly in capacity to restore its original shape after unloading, the improvement in shear wall displacement recovery, wall ductility, hysteric behavior and inter-story drift ratio is presented. For this purpose, experiment study on large scale shear walls with aspect ratio 1.9 is conducted to investigate the effect of the intensity of NiTi on cyclic response. Two ordinary walls, as reference structures, and two hybrid walls are set up in order to perform the study. In addition, the validation of numerical simulation is examined by comparing its results with that obtained by the experiments and a pretty much in agreement is found. Hence, three-dimensional modeling by mean of ANSYS19 is extended to study the effect of NiTi length throughout the wall height on the shear wall response. The results showed that the existing of NiTi controls the cracks propagation and confines the majority in the lower third of the wall. Furthermore, for NiTi-wall, the study showed remarkable enhancement in recover capacity by 77 % and significantly increase in drift capacity ratio by 16.5 % relies on the NiTi ratio. Besides, some significant observations like the profile of wall curvature and energy dissipation are analyzed in this paper.