A FEM-DBEM investigation of the influence of process parameters on crack growth in aluminum friction stir welded butt joints

This paper deals with a numerical investigation on the influence of FSW process parameters, namely the rotating speed and the welding speed, on fatigue crack growth in AA2024-T3 butt joints. The computational approach is based on a sequential usage of Finite Element Method (FEM) and Dual Boundary Element Method (DBEM) procedure. The process induced residual stress distribution has been mapped by means of a recently developed technique named contour method. The computed residual stress field has then been superimposed to the stress field produced by a remote fatigue traction load in a DBEM environment. A two-parameters crack growth law is used for the crack propagation rate assessment. The simulation results corresponding to different combinations of process parameters are presented. The influence of process parameters on the residual stresses distribution has also been highlighted.