800MPa高强钢T形截面轴压构件极限承载力有限元分析

Finite Element Analysis of Ultimate Load Bearing Capacity of T-shaped Section Axial Compression Members of 800 MPa High-strength Steel

针对800MPa高强钢T形截面轴压构件失稳问题,基于ABAQUS软件建立有限元计算模型,分析残余应力、几何初始缺陷、翼缘宽厚比、腹板高厚比和构件长细比对构件极限承载力的影响,建立正则化长细比与整体稳定系数关系曲线,并将高强钢T形截面轴压构件极限承载力的模拟结果与GB50017—2017系列设计规范进行比较分析。结果表明:建立的有限元模型能够准确模拟试验构件的屈曲行为,残余应力峰值对短柱承载力影响较小,对大长细比构件的承载力影响较大;试件初弯曲和板件翘曲对小长细比构件极限承载力影响较大,随构件长细比增加,构件极限承载力随着翼缘宽厚比变化表现为敏感度降低,腹板的高厚比变化规律与之类似。计算得到的稳定系数与GB50017—2017中b类柱子曲线吻合较好,建议采用b类柱子曲线计算800MPa高强钢焊接T形截面轴压构件的极限承载力。

Aiming at instability of 800 MPa high-strength steel T-shaped section axial compression members,a finite element analysis model was established based on ABAQUS software to analyze the effect of residual stress,geometric initial defects,flange width-thickness ratio,web height-thickness ratio and member length-thinness ratio on the ultimate bearing capacity of the member.A relationship curve between regularized aspect ratio and overall stability coefficient was established,and the simulation results of the ultimate bearing capacity of T-shaped section axial compression members of high-strength steel were compared and analyzed with the GB 50017—2017 series design specifications.The results show that the established finite element model can accurately simulate the buckling behavior of test members,and the peak residual stress has a small effect on the bearing capacity of short column,while it has a significant effect on the bearing capacity of large slenderness members.The initial bending of the test piece and the buckling of the plate have a significant effect on the ultimate bearing capacity of small slenderness members.With the increase of the member slenderness,the sensitivity of the ultimate bearing capacity of the member decreases with variation of the flange width-to-thickness ratios,and the variation law of the high-thickness ratio of the web is similar to it.The calculated stability coefficient is in good agreement with the b-class column curve in GB 50017—2017 standard,and it is recommended to use the b-class column curve to calculate the ultimate bearing capacity of axial compression members of 800 MPa high strength steel welded T-shaped section.