基于OpenSEES的RC梁柱组合件低周反复试验数值模拟

Numerical Simulation of a RC Beam-column Sub-assemblage Under Cyclic-reversed Load Based on OpenSEES

梁柱节点是框架结构的关键部位,在地震作用下节点核心区的非弹性变形将导致节点失效甚至结构倒塌。基于某钢筋混凝土框架中间层中节点拟静力试验,利用OpenSEES分析平台,建立了宏观单元分析模型。基于节点区的三种失效机制,采用核心区剪切块、钢筋滑移和交界面剪切三分量组合的方法来模拟节点的二维非弹性性能。用修正压力场理论对核心区剪切块的骨架曲线进行标定。数值模型采用多点位移同步控制的加载模式,用罚刚度法施加位移边界条件。结果表明:经参数标定的数值模型较好地模拟了捏拢效应、加卸载路径和强度退化;但由于节点模型中未考虑楼板,导致梁端底部钢筋较早屈服,反向加载骨架较试验值低。

The beam-column connection is a key component in a moment frame. The inelastic deformation of the joint core area under earthquake loading will result in joint failure and even structural collapse. Based on a quasi-static test, a macro-element model of a 2D RC interior beam-column sub-assemblage was built on the OpenSEES platform. A combination of shear penal component, bar slip and interface shear was used to simu- late the joint nonlinear responce in accordance with its three typical failure mechanisms. The backbone of the shear penal was calibrated with the modified compression field theory （MCFT）. A multi-point displacement- control loading pattern was adopted and the penalty method was used to update the boundary condition. Results show that the proposed model well predicts the pinching effect, unloading/reloading history and strength degra- dation. Due to the neglection of slab contribution in this joint model, bottom rebars at beam tip exabhit prema- ture yielding and the simulated backbone curve in the retro-loading direction lies below the test result curve.