TWI Industrial Member Report Summary 780/2003
N Bagshaw, E Olden and D Bertaso
Buckling distortion can be a severe problem in thin-walled structures that are fusion welded particularly in the aerospace and automotive industries. The local non-uniform heating produced by the welding process causes incompatible compressive plastic strains to develop in the weld zone. Residual stresses are then formed during cooling. The longitudinal tensile residual stresses (along the weld) are balanced in equilibrium with compressive stresses away from the weld. If the compressive stresses are larger than a critical value, the plate will buckle. Low stress no distortion (LSND) welding aims to reduce plastic strains in the weld zone, providing a weld with low residual stresses and minimum distortion. Several LSND techniques have been developed, in which heat sources or cooling devices are applied to regions close to the weld.
To develop finite element methods for prediction of buckling distortion in test specimens using conventional and LSND welding conditions.