Fiber-matrix debonding in composite materials: Axial loading

Abstract

The propagation of fiber-matrix interfacial debonding under axial loading is analyzed, using the single-fiber fragmentation test as a reference, in order to determine fiber-matrix failure properties. A data reduction technique is presented in which the fiber-matrix Mode II interfacial fracture toughness is obtained from the measurements of the average debond crack growth. A set of boundary element models are employed to evaluate the energy release rate associated with interfacial crack propagation. The interfacial friction coefficient is parametrically varied until a constant value of the energy release rate (which is then equal to the fiber-matrix Mode II interfacial fracture toughness) is obtained. The applicability of the properties evaluated is demonstrated using a set of finite element models with cohesive elements.