Fatigue life prediction of automobile component after bake hardening process based on proposed cyclic elastoplastic damage model

Bake hardening is an efficient method for enhancing the strength and providing surface protection for automobile components. However, accurately predicting fatigue life after bake hardening remains a significant challenge. In this study, a finite element-based fatigue life prediction model is developed, integrating the Chaboche mixed hardening constitutive framework with bake hardening effects and cyclic elastoplastic damage theory. The model accounts for stress, strain, and damage evolution, enabling accurate predictions of fatigue life post-bake hardening. The results demonstrate that bake hardening significantly improves the material’s yield strength and delays the onset of plastic deformation, effectively extending fatigue life at low strain amplitudes. At higher strain amplitudes, despite the increase in yield strength, improvements in fatigue life are limited due to reduced plasticity. The model is validated using both experimental data and simulation results, showing high predictive accuracy both before and after bake hardening. This study bridges the gap between fundamental material behavior and practical engineering applications, offering a robust and reliable approach for predicting fatigue life after bake hardening. The proposed model holds significant potential for applications in automobile and other industries where fatigue resistance is critical.