Grain boundary engineering (GBE) plays a critical role in extending the fatigue life of metallic materials by tailoring the grain boundary network to resist crack initiation and slow crack propagation. In austenitic stainless steels, fatigue cracks often nucleate preferentially at grain boundaries, especially under low-stress amplitude conditions. By increasing the fraction of special low-energy boundaries and reducing the connectivity of random high-angle boundaries, GBE alters the crack path, enhances crack deflection, and provides effective barriers to crack growth. As a result, grain boundaries act not only as potential crack initiation sites but also as obstacles that impede or redirect crack propagation, thereby improving overall fatigue resistance.

A segmentation fault in ABAQUS/Explicit indicates that the program attempted to access an invalid memory location. This error can arise from several causes. The first step is to carefully check any user-defined subroutines (e.g., Fortran routines) to ensure that all arguments are correctly typed and ordered, since mismatches often trigger such faults. If the error is reproducible at the same point in every run, it may indicate a software bug or an issue in the user’s code. If, however, the error occurs randomly, it is more likely related to hardware issues such as insufficient memory, overheating, or instability in the computing environment. Running the code with debugging enabled and using a debugger can help identify the precise source of the problem.