高强钢焊接方形截面偏压构件整体和局部相关屈曲承载力分析

Analysis on the ultimate carrying capacities of local-overall interaction of high-strength steel welded square-box section columns loaded with eccentricity

采用有限元软件ANSYS分析了Q460钢宽厚比超限的焊接方形截面偏压构件的极限承载力,研究了板件宽厚比、构件长细比和偏心距对构件极限承载力的影响。基于数值模拟结果,提出了适用于Q460钢宽厚比超限焊接方形截面偏压构件极限承载力的计算方法。研究结果表明,考虑几何缺陷及残余应力的有限元模型能准确地预测焊接箱形截面偏压柱局部-整体相关屈曲的极限承载力;宽厚比超限的高强钢压弯构件的Pu/Py与Mu/Mp相关曲线基本为直线,且随着板件宽厚比(或构件长细比)的增大,Pu/Py和Mu/Mp不断下降。提出的建议计算方法与有限元计算结果符合良好。

The ultimate bearing capacities of welded square-box section members, which were loaded with eccentricity and made from high strength steel Q460 with large width-to-thickness ratios were analyzed by finite element program ANSYS. The effect of plate width-to-thickness ratio, slenderness ratio and eccentricity length on the ultimate bearing capacity was studied. Based on the numerical simulation results, the calculation formulas were proposed to predict the ultimate strength of eccentrically loaded Q460 steel columns with large width-to-thickness ratios. Results show that the finite element model considering the geometric imperfections and residual stress can accurately predict the local-overall interaction buckling ultimate strength of the eccentrically loaded box-section columns with slender plates. The correlation curves of the Pu/Py and Mu/MP are close to straight lines and the values of Pu/Py and Mu/Mp decrease along with the increase of plate width- to-thickness ratio （ or slenderness ratio）. The proposed calculation formulas are in good agreement with the numerical results.