【摘要】 合理、准确地模拟钢筋混凝土梁柱构件的非线性及断裂破坏行为,对于进行钢筋混凝土框架结构在强震作用下的倒塌破坏机制研究具有重要的意义。基于有限元软件ABAQUS的显式求解模块Explicit,研究了钢筋混凝土梁柱构件纤维梁单元的构型及其单元消除技术,构建了包含材料破坏准则的钢筋、混凝土单轴本构关系,并利用用户材料接口VUMAT编制了相应的计算子程序。为验证上述方法的合理性和正确性,本文对轴压与侧向往复加载下钢筋混凝土柱构件的受力破坏全过程进行了数值模拟。计算结果表明:采用单元消除(杀死)可以简单、有效地实现有限单元法对于梁柱构件断裂破坏过程的模拟;基于纤维梁单元构建的材料单轴本构关系和破坏准则能够准确、细致地描述钢筋混凝土柱在荷载作用下的非线性性能发展、构件截面的渐进破坏过程以及残余构件的运动状态;对于非线性性态发展较为强烈的结构构件,考虑材料失效的模拟分析结果更为合理、可信。该方法可用于钢筋混凝土框架结构在强震下倒塌全过程的模拟分析。更多还原

【Abstract】 Rationally and precisely simulating the nonlinear and fracture behavior of RC beam-column members is important to understanding the collapse mechanism of RC frame structures under severe earthquakes. In this study,the allocation and removal of fiber beam model for RC beam-column members is studied based on ABAQUS / Explicit,and the uniaxial constitutive relationship and material failure criterion of concrete and steel reinforcement is studied.Furthermore,a calculation subroutine is developed by utilizing the user material interface VUMAT. To verify the validity of the proposed method,the failure processes of two reinforced concrete column members are simulated under axial loading and lateral reversal loading,respectively. The results indicate that the fracture and failure process of members can be simply and effectively simulated based on the element removal technique. The fiber beam model combined with the proposed constitutive models and failure criterion can effectively and accurately capture the nonlinear behavior of RC columns,the gradual failure process of section as well as the motion state of residual member. For the nonlinear performance of RC structures and its components,the analyzing result is more reasonable and reliable particularly when the material failure is considered. The proposed method can be used for analyzing the entire collapse process of RC frame structures under strong earthquakes.更多还原