A multi phase-field-cohesive zone model for laminated composites: Application to delamination migration

Failure processes in Laminated Fiber-Reinforced Composites (LFRCs) entail the development and progression of different physical mechanisms and, in particular, the interaction between inter-laminar and intra-laminar cracking. Reliable modeling of such complex scenarios can be achieved by developing robust numerical predictive tools that allow for the interaction of both failure modes. In this study, a novel Multi Phase-Field (MPF) model relying on the Puck theory of failure for intra-laminar failure at ply level is coupled with a Cohesive Zone Model (CZM) for inter-laminar cracking. The current computational method is numerically implemented as a system of non-linear coupled equations using the finite element method via user-defined UMAT and UEL subroutines in ABAQUS. The computational tool is applied to qualitatively predict delamination migration in long laminated fiber-reinforced polymers composites comprising 44 cross-ply laminates. The reliability of the current approach is examined via the correlation with experimental results. Finally, the present study is complemented with additional representative examples with the aim of providing further insight into the potential role of different aspects of the system in the delamination migration, including (i) the variation of the ply angle in the migration zone, (ii) the load application point, and (iii) initial crack length.