Fracture Analysis of Fiber Reinforced Composites with Pore Defects Based on Phase Field Method

In engineering applications, due to process limitations, defects such as pores will inevitably appear in the fiber reinforced composites (FRC) structure, and these defects have a negative impact on the mechanical properties of the structure. Therefore, it is very important to quantitatively study the mechanism of the influence of defects on the mechanical properties of materials such as strength and stiffness. Firstly, present study employs the phase field method to model the initiation and propagation of mode I cracks in FRC plates with pore defects, and then obtains the numerical solution through finite element method (FEM). Through comparing the numerical solution with experimental data, the effectiveness of present FEM algorithm is verified. Then, we conduct a comparative parametric study on the fracture behavior of straight fiber and curved fiber reinforced composite plates with pore defects, focusing on the parameters, such as fiber angle, fiber curve concavity and convexity. We found that compared with straight fibers, curved fibers can effectively enhance the strength of the material and structural stability when the composite plate is partially fractured. Additionally, the crack propagation can be effectively guided by the angle of the curved fibers. Present study can provide theoretical guidance for the optimal design of FRC plates with pores in practical engineering applications.