Membrane Residual Stress of Q690 High-Strength Steel Welded H-Section

Abstract

The residual compressive stress ratio of high-strength steel (HSS) members with welded sections is significantly lower than that of common mild steel (CMS) members. However, current codes apply the residual stress results of CMS members to HSS members without adjustment. This study investigated the membrane residual stress distribution of a Q690 HSS welded H-section. The membrane residual stresses of five specimens of different sizes were measured using the sectioning method, resulting in simplified membrane residual stress distribution models. The influences of the width-thickness ratio of the flange and web and the thickness of the flange and web were analyzed. The results indicated that while the welding membrane residual stress satisfied the self-equilibrium of the section, the self-equilibrium of the plates followed an inconsistent pattern. A three-dimensional thermal elastic–plastic finite element model (3DTEFEM) was established to simulate the specimen welding process, and the measured results were used to verify the 3DTEFEM. This model was then used to conduct parameter analysis on the plate width-thickness ratio of the H-section, leading to the development of a unified membrane residual stress pattern for the Q690 steel welded H-section member.