基于等效框架模型的砌体结构抗震模拟及验证

Seismic simulation and verification of masonry structure based on equivalent frame model

等效框架模型采用宏观模型来模拟砌体墙在平面内的抗震性能。砌体墙的墙柱和墙梁采用同时考虑轴向弯曲和剪切变形的基于力法的纤维截面进行模拟,且两者的连接视为刚性区域。轴向压缩及弯曲效应在截面纤维模型中考虑,而剪切效应由V-γ剪切恢复力模型表达,弯曲和剪切在单元层面进行耦合。通过统计和分析,确定骨架曲线的计算方法,并基于Ibarra-Krawinkler模型提出剪切恢复力模型。通过算例得出:该模型在单调加载和循环加载下的数值计算结果与试验结果均吻合较好。

The masonry walls are modeled with macroelements to represent the in-plane nonlinear behavior of the panels when the equivalent frame model is adopted. The spandrels and the piers of the masonry wall are modeled by using the force-based fiber section, which can consider both axial bending and shear deformation. And the connections of spandrels and piers are deemed as rigid. The axial compression and bending behavior are considered in fiber section model, while the shear behavior is considered through shear restoring force model, V-γ and the flexure-shear coupling is presented at the element level. The calculation method of the skeleton curve is determined by statistics and analyses, and the shear restoring force model is proposed based on the Ibarra-Krawinkler model. The numerical results of the model under both the monotonic and cyclic loadings are in good agreement with the experimental results.