Finite element analysis of laser welding induced thermal shock

The thermal and mechanical responses of a weldment involving a girth fillet weld are approximated by the finite element method and an isothermal ring heat source. Approximately 0.1 ms after the application of the ring heat source, the radial traction at an analytically predicted depth and location within the weldment exceeds the failure strength in tension, followed by fracture. Swelling and elongation of the weldment are in evidence in the general vicinity of the ring heat source. Loading characteristics of a corrective fixture are applied to control the radial traction and dilational motion and to gain design/processing knowledge. The analytical model yields an insight into the physical behavior of the subject weldment during CO2 laser beam welding.