Numerical Simulation of Residual Stresses in Structural Steel Members

Structural steel members develop residual stresses due to manufacturing and fabrication processes. Depending on size and welding procedure, these residual stresses in steel members can vary significantly in magnitude and distribution. Hence, it is challenging to reliably predict the magnitude and distribution of residual stresses in steel structural members and connections which can substantially affect their structural performances including local and global flange buckling strengths, seismic performances, and low-cycle fatigue responses. Residual stresses are either ignored or a simplified distribution is assumed in the analysis and design of structural members. This paper presents a numerical scheme to simulate multiaxial residual stresses in steel structural members and connections by using a sequentially coupled thermo-mechanical analysis. Residual stresses induced by welding processes and nonuniform cooling after hot rolling are simulated. The analysis considers the effects of phase transformation, the material heterogeneity in the heat-affected zone induced by welding, and the weld sequence. The simulation technique is validated against several experimental responses demonstrating the robustness of the simulation scheme. The developed numerical scheme provides an advanced technique for simulating multiaxial residual stresses in structural steel members and connections for use in structural analysis and design of steel building frames.