残余应力对冷弯厚壁方矩管轴压承载力的影响

Effect of Residual Stress on the Bearing Capacity of Axially Loaded Cold-Formed Thick-Walled Square and Rectangular Steel Tubes

根据已有残余应力分布模型对冷弯厚壁型钢典型截面进行了理论分析,得到残余应力对冷弯厚壁型钢轴压构件承载力的影响规律。在理论分析的基础上对不同厚度、不同宽厚比的Q235、Q345冷弯厚壁型钢进行有限元分析,得到不同长细比的各构件在考虑和不考虑残余应力两种情况下的轴压承载力,并研究残余应力对冷弯厚壁型钢长柱轴压承载力的影响。结果表明:残余应力对冷弯厚壁型钢轴压承载力的影响在长细比为90时达到最大,且对Q235钢的影响比Q345钢的影响略小。根据有限元分析结果提出了冷弯厚壁型钢轴压构件受残余应力影响程度的计算公式。结果表明:计算公式具有较高的精度。

Theoretical analysis of the effect of residual stress on the bearing capacity of axially loaded cold-formed thick-walled steel members is carried out for typical sections according to existed residual stress model.Based on theoretical analysis results,finite element analysis models are built with and without residual stress respectively for Q235 and Q345 cold-formed thick-walled steel members with different thicknesses and width-thickness ratios to obtain the bearing capacity under axial load,and the effect of residual stress on the bearing capacity of axially loaded cold-formed thick-walled steel members is investigated.It is shown that the effect of residual stress reaches the maximum value when the slenderness ratio equals 90,and the effect on Q235 steel members is slightly lower than that on Q345 steel members.Also,a formula is proposed according to the finite element analysis results to calculate the effect of residual stress on the bearing capacity of axially loaded cold-formed thick-walled steel members,and it is shown that the formula has a good prediction result.