Experiments and numerical simulations on dynamic crack behavior at the interface of layered brittle material

Crack behavior at the interface between two materials is the core problem of layered material fracturing. In this paper, first, experimental tests were conducted on layered material using a drop weight test system following the caustics method. The layered material was made of poly (methyl methacrylate) (PMMA) and epoxy resin bonded with Loctite-330 at two inclination angles (30 degrees and 60 degrees). A corresponding numerical simulation was carried out using continuum-discontinuum element methods. Crack propagation is found to mainly occur in mode I in the PMMA and epoxy resin but follows a mixed cracking mode at the interface. The fracture parameters of the crack tip in the layered materials changed substantially owing to the existence and change of the interface structure. After the crack enters the interface, the crack propagation speed increases significantly. Higher crack dip angles are associated with greater crack propagation speed increases after entering the interface. The simulation results indicate that the interface strength properties affect crack behavior at the interface. This effect also varies as a function of interface inclination and impact velocity