Buckling Distortions and Mitigation Techniques for Thin-Section Structures

The underlying mechanisms associated with welding-induced buckling distortions are investigated using finite element procedures. Unlike stable type of welding-induced distortions which can be adequately captured by performing a thermo-plasticity simulation of actual welding procedures, local buckling distortions in welded structures are of an unstable type, which requires the use of appropriate buckling analysis procedures incorporating welding-induced residual stress state. With the underlying mechanisms in buckling distortions being established, two effective mitigation techniques were presented. One is trailing heat sink and the other is in-process synchronized rolling techniques. Detailed finite element simulations were performed to demonstrate how some of the important process parameters can be established in effectively reducing or eliminating the buckling distortions. The proposed techniques were also validated by laboratory welding trials. The underlying principles and potential applications of the distortion mitigation techniques are also discussed in light of the detailed finite element simulation results.