Microstructure-sensitivity of CPFEM models on fretting fatigue crack initiation of AA2024-T351 alloy
Qingqing Chen, Yazhou Xu, Xiaoyu Zheng
Abstract
The AA2024-T351 alloy is widely used in civil engineering , machinery, and aerospace industries for bolts, rivets, and thin plate components. When in service within these fields, the components are susceptible to performance degradation and fracture failure due to fretting fatigue . In this study, a crystal plastic finite element method (CPFEM) model incorporating microstructure sensitivity is employed to predict the fretting fatigue crack initiation (FFCI) location and lifetime. The submodel method is utilized to simulate various microstructures in the contact region of the specimen under fretting fatigue. This research focuses on two fatigue indicator parameters (FIPs): accumulated plastic slip p and FIP FS , used to determine the hotspots for crack nucleation on the contact surface and subsurface in fretting fatigue. The study explores the impact of different grain size and orientation on crack nucleation and analyzes how various microstructural characteristics influence the crack initiation lifetime. The findings indicate that the influence of grain orientation distribution in fretting fatigue on the initiation location of contact surface cracks is not significant, but it has a notable impact on subsurface cracks. Different grain textures combinations exhibit a more pronounced anisotropy based on the accumulated plastic slip p than FIP FS . Additionally, the effect of grain orientation distribution on the FFCI lifetime is influenced by the average grain size , showing remarkable influence within a specific range of grain sizes.