中美新规范关于焊接薄壁箱形轴压构件稳定承载力设计方法研究

Research on the Design Methods for the Stability Capacity of Welded Thin-Walled Box Columns in the New Chinese and American Standards

和前一版本相比,我国《钢结构设计标准》(GB 50017—2017)(简称《钢标》)和美国钢结构规范(ANSI/AISC 360-16)(简称《16版美标》)均对焊接薄壁箱形截面轴心受压构件的相关条文做了较大修正。修正后的计算公式是否能很好地预测焊接薄壁箱形截面轴心受压构件的稳定承载力尚未见报道。对比了两国新旧版本规范的相关内容,收集了名义屈服强度为235~690 MPa钢焊接薄壁箱形截面轴心受压构件的试验结果和有限元结果,并验证了《钢标》和《16版美标》相关条文的适用性。已有试验和有限元结果表明:《钢标》按b类截面计算构件的稳定承载力较为保守,特别是对于大长细比和大宽厚比构件,如果改为按a类截面计算则偏不安全;《16版美标》偏不安全。

Compared with previous version,the corresponding provisions on welded thin-walled box columns made a major correction in the Standard for Design of Steel Structures(GB 50017—2017)and the American Specification ANSI/AISC 360-16.However,whether the modified formulas can reasonably predict the stability bearing capacity of centrically loaded welded thin-walled box members is unknown.In this paper,the relevant provisions of new and previous versions of the Chinese and American standards are compared,and the experimental results and finite element results of welded thin-walled box columns made from steels with the nominal yield stresses between 235 MPa and 690 MPa are collected to verify the applicability of corresponding provisions in the GB 50017—2017 and ANSI/AISC 360-16.The existing experimental results and finite element results show that the GB 50017—2017 is more conservative when curve b is used to calculate the stability bearing capacity of members,especially for the members with large slenderness ratios and large width-to-thickness ratios,and it is unsafe when curve a is employed,and that the ANSI/AISC 360-16 is unsafe.