Evaluation of Shear Strength Degradation after Flexural Yielding of RC Member

采用三维刚体弹簧模型对循环荷载作用下钢筋混凝土构件弯曲屈服后的抗剪强度退化过程进行了数值模拟和试验研究。首先，对循环荷载作用下钢筋混凝土梁弯曲屈服后的剪切破坏进行了模拟，验证了三维RBSM方法的适用性。在此基础上，提出了一种评价抗弯屈服后抗剪强度退化过程的方法。结果表明，由分析得到的强度退化曲线与由统计方法得到的强度退化曲线具有相似的行为。此外，还分析了腹筋率、轴力和拉筋率对剪切退化曲线的影响。另一方面，提出了一种抗剪强度退化的试验评价方法，并验证了该方法的有效性。

The degradation process of shear strength after flexural yielding of RC member subjected to cyclic loading was evaluated numerically and experimentally.Regarding numerical method, 3D Rigid Body Spring Model (3D RBSM) was used. Firstly, shear failure after flexural yielding of RC beam subjected to cyclic loading was simulated and applicability of 3D RBSM was confirmed. Then, a method which can evaluate the degradation process of shear strength after flexural yielding was proposed. It was shown that the strength degradation curve obtained by analysis shows similar behavior with the equation obtained by statistical procedure. Moreover, the effects of web reinforcement ratio, axial force and tensile reinforcement ratio on shear degradation curve were evaluated. On the other hand, a method to evaluate shear strength degradation experimentally was proposed and the effectiveness of the proposed method was confirmed.