Research on Transverse Crack Problems in Fiber-Reinforced Composites With the Distributed Dislocation Method

Under uniaxial tensile loading, the interaction between matrix cracks and interfacial cracks in fiber-reinforced composites within an infinite plane medium was investigated with the distributed dislocation method (DDM). With crack surfaces represented as continuously distributed dislocations, the composite fracture problem was transformed into a 2D boundary-value problem containing circular elastic inhomogeneities. Based on the superposition principle, the problem was decomposed into 2 sub-problems. The stress intensity factors (SIFs), the stress fields, the maximum tensile stress at the interface, and the energy release rates at the tips of both the matrix crack and the interfacial crack were derived. The crack propagation direction was determined through comparison of the ratio of maximum energy release rates at the crack tips. The results demonstrate that, when inclusions are located in the region ahead of the matrix crack tip, they will exert a shielding effect on crack propagation. Conversely, inclusions in other regions will amplify the crack growth. The initiation of interfacial cracks is primarily attributed to the maximum tensile stress at the interface. When the matrix crack tip approaches the interfacial crack tip, mutual promotion of propagation will occur between both cracks, and the closer their proximity is, the more pronounced the interfacial crack propagation will be due to reduced resistance to debonding.