Q460高强钢焊接T形截面纵向残余应力分布

Longitudinal residual stress distribution of Q460 highstrength steel welded T-section

采用分割法测量了4个Q460高强钢焊接T形截面的纵向残余应力分布;借助通用有限元程序ANSYS,采用热-结构耦合分析方法模拟钢板的切割和焊接过程,将数值模拟获得的纵向残余应力与试验值进行对比,从而验证有限元分析过程的正确性;基于有限元方法获得更多不同截面尺寸的Q460高强钢焊接T形截面纵向残余应力分布,对丰富的数据进行汇总分析,重点研究板件宽厚比和板厚对残余应力大小及分布的影响.结果表明,残余拉应力分布在焊缝周边区域、翼缘和腹板外伸端,残余压应力则分布在翼缘外伸段中部及腹板中部区域;残余拉应力与板件宽厚比和板厚均无关,残余压应力与板件宽厚比和板厚成反比;翼缘和腹板的残余应力均达到自平衡.提出的Q460高强钢焊接T形截面纵向残余应力分布模型,可为后续钢压杆的整体稳定承载力数值分析提供重要参考.

Longitudinal residual stress is one of the main factors affecting the ultimate bearing capacity of steel compression members.Firstly,the longitudinal residual stress distribution of four Q460 high-strength steel welded T-sections was measured using the sectioning method.Secondly,a thermalstructural coupling analysis method was used in general finite element program ANSYS to simulate the cutting and welding processes of the steel plates.The numerical results of longitudinal residual stress were then compared with experimental values to verify the correctness of the finite element analysis process.Furthermore,based on the finite element method,longitudinal residual stress distributions of Q460 high-strength steel welded T-sections with different cross-sectional dimensions were obtained,and a summary analysis was conducted to study the effects of the width-thickness ratio and thickness on the magnitude and distribution of residual stress.The results show that the tensile residual stress is distributed in the area around the weld,the outer extension of the flange and web,while the compressive residual stress is distributed in the middle part of the outer extension of the flange and web.Moreover,the tensile residual stress is independent of the width-thickness ratio and the plate thickness,while the compressive residual stress is inversely proportional to the width-thickness ratio and plate thickness.The residual stress in the flange and web is accord with the self-equilibrium condition.According to the above analysis,a longitudinal residual stress distribution model for Q460 high-strength steel welded T-section is proposed,which can be used for the subsequent numerical analysis of the overall stability and bearing capacity of steel compression members.