Numerical simulation of fatigue crack growth in friction stir welded T joint made of Al 2024 T351 alloy

摘要

The Extended Finite Element Method (xFEM) has been applied to simulate fatigue crack growth in an AA2024-T351 T welded joint, 5 mm thick, made by friction stir welding. The ABAQUS and Morfeo software has been used. Tensile fatigue loading (mean stress 10 MPa, stress ratio R=0) is applied to Tjoints with a configuration suitable for reinforced panels where both skin and the web (reinforcement or stiffener) is made of a high strength AA2024-T351. Crack is introduced in one edge of the skin base material. The properties of materials in the areas of joints and geometry measures of Tjoint are adopted from available experiments. Following numerical results are obtained: crack front coordinates (x, y, z) and stress intensity factors (K_I, K_(II), K_(III) and K_(ef)) distribution along the crack tip, as well as the fatigue life estimation for every crack propagation step. The main objective of this research is to better understand fatigue behaviour of friction stir welded Tjoint of AA2024-T351.