5577 - EFFECT OF RESIDUAL STRESSES DUE TO LASER WELDING ON THE STRESS INTENSITY FACTORS OF ADJACENT CRACK

In the present work the effect of residual stresses due to laser welding on the Stress Intensity Factors (SIFs) of cracks developing nearby the welded area is studied. The simulation of the welding process and the calculation of SIFs on the cracked structure are performed using an explicit and an implicit Finite Element code, respectively. The developed residual stresses due to the welding of two flat plates by laser are calculated first, using a thermo-mechanical transient analysis. Consequently, a linear elastic analysis is applied on the calculation of SIFs at the crack tips. The calculated results of the welding simulation are verified by comparing the computed angular distortions to the corresponding experimental values. As SIF values can not be experimentally determined due to the existence of the residual stress field, the verification of the fracture mechanics analysis is performed through comparisons between computed and experimental crack opening displacement (COD) values. Concerning both analysis types, a good agreement between experimental and theoretical results is observed.