Q460高强钢焊接H形柱轴心受压极限承载力参数分析

Parametric Study on the Ultimate Load-Bearing Capacity of Q460 High Strength Steel H-Shaped Columns under Axial Compression

为了研究现行钢结构设计规范是否仍适用于高强钢中厚板焊接H形柱的设计,采用数值积分法与有限单元法对Q460钢轴心受压柱的极限承载力进行了参数分析。试件的主要参数分别为翼缘宽厚比(3.4~7.0)与柱长细比(10~130)。数值积分法计算采用作者编制的电算程序,并与通用有限元程序ANSYS的计算结果进行了对比。数值模型考虑了1/1 000柱长的初始弯曲及相应截面的残余应力分布简化模型。计算结果表明:考虑相同初始缺陷的有限单元法与数值积分法所得计算结果吻合较好;Q460高强钢焰割边焊接H形柱与普通强度钢柱相比,其极限承载力对初始几何缺陷的敏感性降低,柱的稳定系数有所提高。通过对比参数分析结果与现行规范,发现当翼缘宽厚比不小于7时,中厚板Q460高强钢焰割边焊接H形柱绕弱轴稳定系数仍可沿用《钢结构设计规范》(GB 50017—2003)中b类截面柱子曲线;当翼缘宽厚比小于7时,应采用c类截面柱子曲线。

This paper presents a parametric study on the ultimate load-bearing capacity of H-shaped columns made of Q460 steel under axial compression.The purpose of this study was to expand the applicability of the current design codes to account for the design of high strength steel columns,such as Q460 steel.The main factors investigated in the parametric study are width-to-thickness ratio of flange(3.4 to 7.0)and slenderness of column(10 to 130),and both numerical model and commercial finite element analysis software(ANSYS)were applied to carry out the analysis.The numerical model is based on numerical integration method(NIM),and it accounts for initial geometric imperfections,eccentricity,and residual stresses in the column.Based on the analysis results,the predictions obtained from NIM model have a good agreement with finite element analysis results.Also,the results indicate when width-to-thickness ratio of flange plate is larger than 7,the design of Q460 high strength steel columns can follow Curve b for ordinary steel columns specified in GB 50017—2003.Otherwise,Curve c specified in GB 50017—2003 should be adopted.