基于OpenSees的强震下混凝土结构梁-梁碰撞行为数值实现

绝大多数针对极端作用下的结构连续倒塌分析,在分析过程中不能实时地根据构件的损伤状态对分析模型进行修改,也不能考虑连续倒塌过程中的各种碰撞问题。连续倒塌过程中发生的碰撞对结构响应预测有重大影响。本文依据钢筋混凝土框架结构发生梁-梁碰撞的机理,基于OpenSees平台建模,结合Matlab的混合编程计算碰撞力,通过添加碰撞时程力并对结构进行模型更新,合理地实现钢筋混凝土框架结构在强震作用下的连续倒塌过程中发生梁-梁碰撞的具体过程。将得到的结果和传统时程分析法的结果进行的对比表明,结合Matlab和OpenSees命令可以实时地计算碰撞力序列和对结构进行更新,梁-梁碰撞和构件的逐步失效使结构的水平位移和转角有一定的增大,竖向位移有一定减小。

OpenSees-based Numerical Implementation of Beam-to-Beam Impact Behavior of Concrete Structures Subjected to Strong Earthquakes

Most investigations on progressive collapse analysis of structures subjected to extreme actions cannot modify analytical model according to real-time damage evolution status,and various impact processes caused by failed structural components during progressive collapse cannot be considered as well. Such issues associated with impact are truly crucial in numerically predicting structural responses during progressive collapse analysis. According to the beam-to-beam impact mechanism developed for reinforced concrete frame structures,impact force-time history is determined by using Matlab language and then is incorporated into OpenSees platform to modify structural model. The effect of beam-to-beam impact behavior on the responses of RC concrete frame structures excited by strong earthquakes can be reasonably reflected. The results of these procedures are compared with those from conventional time history analysis for an example RC frame. It can be concluded that the incorporation of Matlab and OpenSees Tcl language can compute impact force time history and modify structural model in real-time. With the consideration of beam-to-beam impact and progressive failure of components,the horizontal displacement and rotation of the structure increase while the vertical displacement decreases to some extent.