Overall buckling behavior and design of Q690 steel welded H-columns under axial compression
Li Guoqiang1 Li Tianji2 Wang Yanbo3
1. State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China;
2. Shanghai Construction No.5 (Group) Co., Ltd., Shanghai 200063, China;
3. College of Civil Engineering, Tongji University, Shanghai 200092, China
Abstract：This paper aims to study the overall buckling behavior of Q690 steel H-columns and provide some proposals for design of such columns. To this, the residual stress distribution of H-section specimens made of Q690 steels was measured by the sectioning method, and the simplified residual stress models related to such specimens were proposed. Moreover, an experimental study on the overall buckling behavior of welded H-columns with the steel grade under axial compression was carried out. Based on the experimental results, the overall buckling behavior and failure model of the axially loaded columns were discussed. Subsequently, with the direct analysis method，the numerical model was established and verified by comparing the experiment results. In the model, Pointwise-Equilibrating-Polynomial (PEP) element is used to simulate the member initial imperfection. The plastic fiber hinge method combined with the use of sectional yield surfaces is applied to reflect inelastic yielding at the critical location. A cross-sectional analysis approach allowing for residual stresses modeling is also incorporated into the numerical method. Eventually, parametric study of the Q690 steel H-column specimens is conducted through the direct analysis method. Based on the results of the parametric study, some suggestions for design of such columns are presented.
