钢筋混凝土梁柱边节点滞回性能数值模拟

Numerical simulation of the hysteretic performance of exterior reinforced concrete beam-column joints

为准确模拟梁柱边节点在地震条件作用下的滞回响应,建立考虑黏结退化机制的梁柱边节点有限元模型。基于ANSYS有限元平台,采用Voce-Chaboche混合强化模型定义钢筋的循环本构关系,开发组合弹簧单元实现往复荷载作用下钢筋与混凝土间的黏结退化机制,根据损伤理论提出往复荷载作用下黏结滑移本构关系预测模型。有限元计算得到的滞回曲线、骨架曲线、刚度退化曲线、应力云图与试验结果的对比表明:混合强化本构能更好地描述往复荷载作用下钢筋的滞回响应,组合弹簧单元成功地反演了往复荷载作用下钢筋与混凝土的黏结退化特征,往复荷载作用下节点梁中塑性铰的发育导致梁塑性伸长,将对边节点柱造成不利影响,梁柱边节点数值模拟结果与试验结果吻合良好,为准确模拟梁柱边节点的滞回性能提供了理论基础和技术平台。

In order to accurately simulate the hysteretic response of exterior beam-column joints under seismic conditions element model of exterior beam-column joints that took the bond degradation mechanism into account is established.Based on the ANSYS finite element platform,the Voce-Chaboche combined hardening model is used to define the cyclic constitutive relationship of reinforcement,and the composite spring elements are developed to simulate the bond degradation mechanism between steel bar and concrete under reciprocating loading.A prediction model for the bond-slip constitutive relationship under reciprocating loading is proposed based on damage theory.The hysteresis curves,skeleton curves,stiffness degradation curves and stress nephogram obtained from the finite element calculation are compared with the experimental results.The comparison shows that the combined hardening constitutive model can better describe the hysteretic response of steel bars under reciprocating loads.Composite spring elements successfully invert the bond degradation characteristics between steel bars and concrete under reciprocating loads.The development of plastic hinges in the joint beam under reciprocating loads leads to plastic elongation of the beam,which will adversely affect the exterior column.The numerical simulation results are in good agreement with the experimental results,providing an important theoretical basis and technical platform for accurately simulating the hysteretic performance of exterior beam-column joints.