High-cycle fatigue simulation for aluminium alloy using cohesive zone law

摘要

This article describes high-cycle fatigue simulation for 7050-T7451 aluminium alloy using cohesive zone law. A three-dimensional finite element model is developed for fatigue behaviour of aluminium alloy subjected to cyclic bending. A bilinear, cycle-dependent cohesive zone law is implemented with a help of experimental S-N (stress amplitude-number of cycles to failure) data. In the finite element model, a cycle jump strategy is used including stiffness degradation and reduction of fracture energy during cyclic loadings. Additionally, bending experiments are conducted with unnotched specimens and S-N curves are determined. Direct comparison of S-N curves between the simulation and the experiment is performed on bilogarithmic scale. Results show that the proposed method provides a good means of simulating high-cycle fatigue behaviour of aluminium alloys.