国产Q460高强钢焊接T形截面轴心压杆整体稳定承载力研究

Research on overall stability bearing capacity of domestic Q460 high strength steel welded T-section columns under axial compression

为了研究国产Q460高强钢焊接T形截面轴心压杆的整体稳定承载力,用厚度为8mm和12mm的国产Q460高强度钢板制作了3根焊接T形截面试件进行轴心受压试验。基于实测的钢材力学性能、截面残余应力和试件几何尺寸,建立考虑了初始几何缺陷和力学缺陷的有限元模型,分析预测试件的极限承载力,并将有限元结果与试验结果进行对比,验证有限元分析方法的正确性。利用经试验验证的有限元分析方法,补充计算了24根不同长细比压杆的整体稳定极限承载力,将相应的整体稳定系数与《钢结构设计标准》(GB 50017—2017)中的柱子稳定系数曲线进行比较。研究表明,国产Q460高强钢焊接T形截面轴心压杆的整体失稳形式为绕对称轴的弯扭失稳,失稳时压杆进入了弹塑性变形阶段,在设计过程中选取b类截面柱子曲线对其进行计算是安全可靠的。

In order to study the overall stability capacity of domestic Q460 high strength steel welded T-section columns under axial compression,three T-section columns were welded with 8mm-thick and 12mm-thick Q460 high strength steel plates made in China were made for axial compression test.The finite element models were built up according to measured mechanical properties of steel,section residual stress and measured sizes of members.And residual stress and initial geometric imperfection were considered in the finite element models to analyze and predict the ultimate bearing capacity of the columns.The finite element results were compared with the experimental results to verify the correctness of the finite element analysis method.Based on the finite element analysis method verified by experiment,the overall stable ultimate bearing capacity of 24 different slenderness columns were calculated and compared with column stability coefficient curves in Standard for design of steel structures(GB 50017—2017).The study shows that the overall instability form of domestic Q460 high strength steel welded T-section columns was bending and torsional around the symmetry axis,and the compression columns enter the elastic-plastic deformation stage when the instability occurs.It is safe and reliable to select the stability coefficient curve of the type b columns to calculate in the design process.