Study of the buckling mechanism in laser tube forming with axial preloads

The buckling mechanism of a thin metal tube during laser forming with axial preloads was investigated numerically and experimentally in this study. Metal tubes made of 304 stainless steel were heated by a CO2 Gaussian laser beam, which induced the buckling phenomenon on the tube surface due to elastic-plastic deformation. This uncoupled thermal-mechanical problem was solved using a 3D finite element method (FEM) and was subsequently satisfactorily verified with axial force measurements. The transient force response and residual stress of the thin metal tube under specific operation conditions were also studied.