Performance Study of Steel Coupling beams in coupling shear-wall system

Abstract Application of concrete coupling beams using diagonal reinforcement is a common practice which has certain limitations such as issues associated with their execution and their large depth to satisfy the stiffness, strength, and energy dissipation criteria. Steel coupling beams have a higher performance in terms of satisfying the stiffness and strength criteria with respect to the reinforced concrete beams with customary or diagonal reinforcement. 10 and 15-story buildings are designed in accordance with the energy absorption concept or plastic design based on the structure performance. The equivalent column method is used for modeling and the nonlinear behavior of the wall is modeled by two methods. In the first method, which is shown to have a better performance, the nonlinear behavior of the wall is obtained using ABAQUS software and is assigned to the wall base using the lumped plastic hinge method (Link element). The nonlinear behavior is defined in the second method using the semi-lumped plastic hinge (Fiber element). The capacity curves obtained from the pushover analysis show the limited ductility and displacement of concrete coupling beams because of rapid loss in the capacity curves compared with those modeled that used steel coupling beams. The incremental dynamic analysis using 20 earthquake records is performed on 2D models. In this research concluded that at the immediate occupancy performance level both the concrete and steel coupling beams have similar performances and approximately equal failure probabilities. But at the life safety and collapse threshold performance levels the structure with the steel coupling beam exhibits a better performance. Therefore, it seems that in the structures that are designed for IO performance level, there is no advantage between the two types of coupling beams. But at lower performance levels, the steel coupling beam would have a better performance.