Strain induced crack initiation and the subsequent crack propagation of fiber-reinforced resin composites

Fiber-reinforced composite is a kind of excellent lightweight material that has important applications in the fields of aerospace, automotive, etc. However, due to the strong heterogeneous characteristics of its internal microstructures, material properties dramatically changed interfaces, and the rapid brittle damage process, its internal deformation and failure mechanism is a current hot research topic. Here, the synchrotron X-ray computed tomography technology and digital volume correlation method were adopted to investigate the internal three-dimensional deformation and failure evolution of the representative unit of fiber-reinforced resin composites during loading process. It shows that the deformation parameters including the local strain concentration and strain gradient in this fiber-reinforced heterogeneous system have important prediction and guiding effects on crack initiation and the subsequent propagation. These results may have positive significance for revealing the failure mechanisms, as well as microstructure and interface optimization of fiber-reinforced composites.