UMAT Abaqus subroutine to implement the phase field fracture model over pre-defined interfaces (e.g., grain boundaries or fibre-matrix interfaces) such that the phase field only evolves over those.
Paper: K. Au-Yeung, A. Quintanas-Corominas, E. Martínez-Pañeda, W. Tan. Hygroscopic phase field modelling of composite materials. Engineering with Computers 39, 3847–3864 (2023)