Design reliability analysis of cold-formed thick-walled steel members under axial compression.

Axial compression tests and corresponding finite element analysis were conducted on the basis of material property tests. It was shown that the failure mode of long column with a low width-thickness ratio is global instability, while the failure mode of short column with a high width-thickness ratio is that small bending deformation appeared firstly at the center of the column, then the deformation developed with the gradually increasing load and caused local buckling in the end. The results of finite element analysis can fit well with the test results, which means the feasibility and accuracy can be achieved by using this residual stress model into finite element analysis to simulate the axial compression behavior of cold-formed thick-walled steel members. Then, the finite element model was used based on the collected 26 groups of material properties of different tubes with representative size and thickness to get the axial bearing capacity data of members, and design reliability analysis of cold-formed thick-walled steel members under axial compression was conducted. Finally, the resistance partial factor and the design strength for Q235 and Q345 cold-formed thick-walled steel were proposed for the reference in current revising of related design codes. [ABSTRACT FROM AUTHOR]