Toward a high-quality FEM analysis of RC members subjected to reversed cyclic shear

The material models were improved especially in order to represent the cyclic behavior of RC structural members more precisely in two-dimensional FEM analytical program. The transition hysteretic models of tension-compression stresses of concrete, shear stiffness hysteretic models of cracked concrete, and realistic multi-curves hysteretic models of reinforcement were developed. These models could improve the precision of the stiffness and strength degradation, unloading and reloading stiffness, slip stiffness, residual strains and degradation characteristics under reversed cyclic loading in the hysteretic loops of materials. The revised FEM program was applied to RC panels subjected to cyclic shear and normal stresses and RC shear walls surrounded by columns and beams subjected to cyclic shear in order to verify the revised analytical models. The analytical results gave a correct estimation of unloading and reloading hysteretic shape of load-deflection curves and residual displacement as compared with the test results.