Ductile damage behaviour of laser welded joints for titanium and Al–Li alloy sheets

AbstractThe ductile damage behaviour of laser welded joints for titanium alloy and Al–Li alloy sheets was analysed by the finite element method following Gurson–Tvergaard–Needleman model (GTN model). The parameters of GTN model were identified by an inverse identification technique, according to uniaxial stress–strain curves. The stress–stain curves for weld metal (WM) were determined by microtensile tests. It was found that the damage of the over matched titanium alloy joints mainly occurred in the base metal and the damage evolution became faster with increasing width of the WM. The damage of the under matched Al–Li alloy joints mainly occurred in the WM and the damage resistance of the joints increases with increasing width of the WM.