A hybrid phase-field model for dynamic fracture in fiber-reinforced composites considering interfacial debonding

In this work, we develop a hybrid phase-field modeling approach, enhanced by a higher-order nonlocal operator method (NOM) to simulate dynamic brittle fracture in fiber-reinforced composites. This approach captures dynamic fracture patterns in composite materials, including matrix cracking, interfacial debonding, and the interaction between these failure modes. A crack surface density function is applied to incorporate the material anisotropy induced by the fibers. Both weak material anisotropy and coefficient-related strong anisotropy are considered. Moreover, the nonlocal integral form of the dynamic phase-field fracture model is derived using a higher-order NOM. The proposed approach eliminates the need to compute derivatives of the moment matrix. To improve computational accuracy and stability, a nonlocal differential operator derived from the reproducing kernel particle method is employed. The implicit Newmark integration scheme is used for the time discretization of the phase-field governing equations. Numerical examples demonstrate that the proposed method effectively captures the initiation, propagation, and interaction of bulk dynamic fractures and interface cracks, while accurately representing the anisotropic behavior of composite materials.