Pinching Analysis of RC Walls by Fiber Model

It is important to estimate directly the pinching of RC members subjected to cyclic loading. However, in practice the energy dissipation factor is adopted, which is indirect and empirical method. It was reported that the delay of compressive stress development of concrete is the main cause of pinching. In this study the compressive stress delay of concrete is considered in the nonlinear analysis of RC walls subjected to cyclic loading and the effect of the compressive stress delay of concrete on pinching is observed at the hysteresis loop of lateral load-drift ratio graph. Multiple pushover analysis on the RC walls with various vertical end bar ratios were performed by Perform 3D. As results the plastic hinge rotation of RC walls considering the delay of compressive stress development of concrete is evaluated larger than that of walls non-considering stress delay and as the end bar ratio increases the RC walls considering the compressive stress delay of concrete were evaluated differently comparing to the RC walls non-considering compressive stress delay of concrete.

파이버모델을 이용한 RC벽체의 핀칭해석