钢框架梁柱节点子结构抗冲击力学性能有限元仿真研究

摘要

Two kinds of widely used steel anti-moment connections (welded unreinforced flange-welded web and welded unreinforced flange-bolted web)were modeled by using the finite element software ABAQUS,taking the effects of bolt pretension force,contact,nonlinear large deformation and strain rate into consideration.The model was used to simulate beam-column substructures under impact load,and it shows that ABAQUS /explicit solver presents high precision and good stability.As a result,the finite element results of failure mode and time histories of impact load and deformation agree fairly well with experimental results.Under large deformation,the most significant stress concentration locates at the weld access hole,where initiates the whole component failure.The dynamic response and internal force development of beam-column substructures were obtained by simulation analysis.The results of numerical analysis provide a basis for studying the working mechanism of progressive collapse of steel structures and for rationally accessing the ability of resisting collapse deformation and energy dissipation.%基于有限元软件ABAQUS对钢框架节点（全焊节点和栓焊节点）进行了非线性动态响应数值仿真模拟分析，模型合理考虑了螺栓预紧力、接触、非线性大变形及应变率效应等因素。采用该模型模拟梁柱节点子结构抗冲击试验，分析结果表明，采用显示求解器可获得较好精度和稳定性，有限元模拟的破坏模态、冲击力和位移时程曲线等结果与试验结果吻合良好。在大变形下过焊孔趾部是节点应力集中最显著的部位，是整个构件破坏的起始点。通过仿真分析，可获得梁柱节点子结构在冲击荷载作用下的动态响应和内力发展过程，该数值分析方法为深入研究钢结构抗倒塌工作机理并为合理评估其抗倒塌变形和耗能能力提供依据。