A unified anisotropic phase field model for progressive failure of fiber-reinforced composite materials

Abstract

Fiber-reinforced composite materials have gained considerable traction in various applications due to their exceptional properties, but the multicomponent nature makes their failure modes more complex, so the research of failure mechanism for composites is very important for the safety of the structure in use. In this work, a new unified anisotropic phase field model is proposed. Firstly, a new crack surface density function is developed, drawing on the characteristics of both double and single phase field models, as well as the fracture behavior of composites. This new function retains the advantages of the previous models. Meanwhile, to more accurately portray failure behavior in matrix-dominated fractures, a new mixed-mode damage evolution driving force is presented. In addition, the analytical solution of the model is derived, and the relationships between the model parameters and stress and strain, together with crack bandwidth, are established. Furthermore, 2D and 3D Hashin failure criteria are derived from the phase field model, and the damage initiation criterion and evolution law of the model are constructed. Finally, the new model is validated by some examples, and the influences of the model parameters on the load-displacement response and the crack pattern are analyzed. The simulation results align well with the experimental findings, theoretical analyses, and reference numerical results, demonstrating the validity and accuracy of the presented model.