钢筋混凝土柱的滞回性能的模拟及分析

Simulation and analysis of hysteretic property of reinforced concrete columns

本文基于ABAQUS的扩展有限元模块提出一种模拟钢筋混凝土柱抗震性能的新方法,即通过定义断裂性能模拟混凝土的开裂现象和残余变形,避免了人为指定混凝土材性的主观性。此外,该算法还考虑裂缝的开展与闭合、钢筋混凝土的粘结滑移等对钢筋混凝土柱滞回性能的影响。为了验证模型的可行性,对一组钢筋混凝土柱的低周反复试验进行了模拟,通过对比可知,模拟具有较高的精度。最后,通过模拟结果,展示混凝土的滞回本构关系实际上是由裂缝的开展与闭合等行为造成,而并不是简单的材料属性的体现,从机理上说明了反复荷载下混凝土应力-应变曲线的成因。

This article proposed a new method to simulate seismic behavior of reinforced concrete( RC) columns.The method simulates the properties of cracking concrete by defining fracture parameters in extended finite element method( XFEM). Unlike the conventional method,the concrete was considered as a quasi-brittle material,and the initial elastic modulus is the only input value needed for tensile. Moreover,this method takes into account the crack's opening,closing and also the bond slip relationship between concrete and rebar,which was proved to be the critical factors of pinching effect. To verify the feasibility of new model,simulations aimed to a series of open-accessing RC column test were performed. Comparison showed that numerical results had a acceptable agreement to the test data. Additionally,the simulation results show that hysteretic curve actually results from crack opening and closure of concrete rather than material property itself,which illustrates the cause of stress strain relationship of concrete under cyclic load.