Polynomial chaos expansion-based stochastic phase field model for hydrogen-assisted cracking

Hydrogen-assisted cracking presents a significant threat to high-performance metallic materials commonly used in engineering applications. This paper presents a surrogate model based on polynomial chaos expansion method, integrated with a phase field fracture model, to simulate hydrogen-assisted cracking. The proposed approach aims to efficiently and accurately predict the behavior of hydrogen-assisted cracking in materials by integrating material degradation due to hydrogen with the phase field fracture model, while accounting for material property and multi-crack characteristics variability. The surrogate model is constructed using stochastic input variables, such as effective Young's modulus, fracture toughness and multi-crack characteristic control coefficient, thereby reducing the computational cost associated with numerical simulations. To validate the model, several 2D numerical case studies were conducted, demonstrating its ability to capture the initiation, propagation, and final fracture characteristics of hydrogen-assisted cracks. The results indicate that the proposed model can effectively predict the occurrence and progression of hydrogen-assisted cracking, providing a reliable tool for assessing the fracture behavior of high-performance metallic materials under hydrogen embrittlement. Furthermore, this method has broad applicability and can inform material selection and fracture prediction research in other fields.