Study on cross-sectional bearing capacity of laser-welded stainless steel H-section stub columns under axial compression
In order to study the cross-sectional bearing capacity of laser-welded austenitic stainless steel H-section members under axial compression,nine laser-welded stainless steel H-section stub columns were axially loaded,and the cross-sectional bearing capacity of stub columns with stocky and slender sections and the local stability performance of the constituent plates were analyzed.The test results indicate that there is a significant strain hardening stage in the stub columns with stocky sections,and the cross-sectional ultimate bearing capacity is higher than cross-sectional yield bearing capacity.However,due to local buckling of the constituent plates,the cross-sectional ultimate bearing capacity of the stub columns with slender sections is lower than the cross-sectional yield bearing capacity.ABAQUS was used to establish a stub column model,whose applicability was verified by test results,and parametric analysis was carried out to study the influence of local geometric initial imperfections and welding residual stress on the stub column cross-sectional bearing capacity.Based on the test data and FE results,the local stability loading capacity calculation formula in Chinese code CECS 410:2015'Technical specification for stainless steel structures'was evaluated,and the results show that the current code is generally conservative.Through the introduction of strain hardening influence coefficient and the effective width reduction coefficient,the calculation formula in current code was revised.The revised design formula can accurately predict the cross-sectional bearing capacity of welded stainless steel H-section axial compressive members.