EXPERIMENTAL INVESTIGATION OF RESIDUAL STRESS IN WELDED T-SECTION BY DOMESTIC Q460 HIGH STRENGTH STEEL

Residual stress is one of the most important initial imperfections for the buckling behavior of steel compression members. An experimental investigation was carried out to quantify the longitudinal residual stress in welded T-section of domestic Q460 high strength steel. The residual stress of 8 specimens with various dimensions was measured by using the splitting method. Based on the experimental data, the magnitude and distribution of both compressive and tensile residual stresses in the entire section were obtained. It was found that the magnitude of tensile residual stresses near the weld was hardly correlated with the sectional dimension, but the magnitude of compressive residual stress in the flange was inversely proportional to the plate thickness and the width-thickness ratio. Moreover, there was no interaction between the flange and web since the total residual stress was close to zero within each plate. According to those conclusions, the distribution model was proposed and compared well with the experimental results. The new model can be used to describe the residual stress in Q460 HSS welded T-section accurately and reliably.