NUMERICAL SIMULATION OF CORROSION FATIGUE CRACK PROPAGATION BASED ON PERIDYNAMICS THEORY

In order to simulate the crack propagation by corrosion fatigue, a coupled peridynamics corrosion-fatigue fracture model was proposed and applied to the simulation and analysis of crack propagation in A7N01P-T4 aluminum alloy. In this model, the interaction of hydrogen and stress was used to reflect the synergy between the two mechanisms of anodic dissolution and hydrogen cracking in corrosion, and the corrosion solution step and the mechanical solution step were coupled when quantifying the fracture behavior of the material due to corrosion. Since hydrogen reduces the plasticity of the material and brittle fracture occurs, a bonded peridynamics theory suitable for simulating isotropic brittle damage was used, and the relation between near-field force and elongation was described using an intrinsic force function for quasi-brittle materials that incorporates both linear and nonlinear mechanical behavior. The feasibility of the model is verified by comparing the simulation results with the test results of A7N01P-T4 aluminum alloy in 3.5% NaCl solution, and it is found that the results are in good agreement between them.