钢筋混凝土梁柱子结构抗倒塌性能有限元模拟与分析

摘要

Based on ABAQUS/Explicit,a three-dimension nonlinear finite element model was developed to analyze the collapse-resistant behavior of reinforced concrete (RC) beam-column sub-structures.In the model,the progressive damage and failure model (PDFM) in ABAQUS was used to simulate the rupture of steel bars and the concrete damaged plasticity model was used to simulate the behavior of concrete.The value of key parameters in PDFM for steel bar in uniaxial tension was investigated in detail,which makes it more convenient to utilize the PDFM to simulate the rupture of steel bar than to use the user-defined subroutine.The finite element analysis model was validated to describe the response of collapse-resistant behavior of RC beam-column sub-structure with good accuracy by comparing the numerically simulated results with experimental results.Based on the finite element model,the influence of the ultimate tensile strain of longitudinal steel bar on the ultimate load carrying capacity and the corresponding deflection was investigated and the results show that the influence is significant.But no provision in the Code for Design of Concrete Structures refers to the influence.It is needed to further investigate the influence of the ultimate tensile strain of longitudinal steel bar.%基于ABAQUS/Explicit平台,本文分别采用累积损伤破坏模型模拟钢筋受拉断裂行为和混凝土损伤塑性模型模拟混凝土性能,建立了钢筋混凝土梁柱子结构抗倒塌性能分析的三维非线性有限元模型.文中详细地讨论了ABAQUS中累积损伤破坏模型模拟钢筋受拉断裂行为所需关键参数的取值,从而避免了以往采用自定义子程序分析钢筋断裂行为的不便.通过有限元模拟结果与文献中试验研究结果的比较,表明该模型可较好地模拟钢筋混凝土梁柱子结构的抗倒塌性能.基于该模型开展进一步分析,表明钢筋极限拉应变的取值对梁柱子结构抗倒塌极限承载力及对应挠度有重要影响,而目前《混凝土结构设计规范》对这一点并未考虑,有必要对这一问题进一步加强研究.