Welding Numerical Simulations of Joints Between Aluminum Alloy Box Columns and H-Shaped Beams

In order to study the welding residual stress level and distribution law of joints between 6061-T6 aluminum alloy box-columns and H-shaped beams, the finite element software was used to establish the models of beam-column joints reinforced with cover plates, ordinary beam-column joints with column diaphragms, and ordinary beam-column joints without column diaphragms. The indirect thermo-mechanical coupling method was used to carry out the numerical simulation of T-shaped fully penetrated weld welding of the joints, and the finite element model was verified. The results showed that the middle part of longitudinal welding residual stress of the beam flange butt weld and the web butt weld of each joint was about 250 MPa, and the welding residual stress at both ends of the weld tended to 0 MPa. The transverse residual stress of each joint weld was tensile in the middle and was compressed at both ends. The transverse residual stress of the strengthened joint butt weld along the beam-column flange tended to 0 MPa, but the peak value of the ordinary joint was about 240 MPa. The residual stresses at the fillet weld of the cover plate of reinforced joint were tensile stresses, and the overall welding residual stresses were low. The overall results showed that the welding residual stress generated at the weld was large, and the welding residual stress at the butt weld of the web butt weld and the beam-column flange butt weld had reached the yield strength of 6061-T6 aluminum alloy. At the same time, the residual deformation of the upper and lower flanges of the beam concave in the direction of the web of the beam occurred at each joint.