Experimental and numerical study of residual stresses in 550 MPa high strength steel welded angle sections

Abstract

Residual stresses caused by non-uniform cooling after welding significantly affects the mechanical properties of welding members. In this work, the sectioning method is used to investigate the residual stresses in four welded-angle section with the yield strength of 550 MPa (fy). The maximum residual tensile stresses locating at the welding zone are close to the yield strength, and the maximum residual compressive stresses distributed on the middle of plates are around 0.40 fy. The residual stresses distributed in welded-angle section are then observed using finite element method (FEM), which is validated by experimental results, and the influences of several parameters on the residual stresses are discussed. The maximum residual compressive stresses decreases with the increase of the width-to-thickness ratio, b/t, and the tensile residual stresses have no obvious relations with the ratio of b/t. The increase of the yield strength will lead to the increase of residual tensile stresses near the welding region, but its increase has insignificant on the ratio of the residual tensile stresses to the yield strength of steel grade. A distribution model for HSS (i.e., Q460, Q550, and Q690) welded angle section is presented, and it agrees well with data from the experiment and FEM.