The Influence of Debonding Damage on a Crack-Tip Field in Glass-Particle-Reinforced Nylon 66 Composite

This paper deals with the influence of debonding damage between particles and matrix on a crack-tip field in a glass-particle-reinforced nylon 66 composite. In order to explain the influence of debonding damage on the fracture toughness, numerical analysis of a crack-tip field was carried out on the interface-treated and untreated composites by using a finite element method developed on the basis of an incremental damage theory of particle-reinforced composites. At the crack-tip region, the damage zone due to the particle-matrix interfacial debonding develops in addition to the plastic zone due to matrix plasticity. The damage development around a crack-tip depends on the interfacial strength between particle and matrix and the particle volume fraction. It is found that the debonding damage reduces the stress level around a crack-tip and acts as the toughening mechanism. The mechanical performance of particle-reinforced composites is obtained as a result of the competitive effects of the intact hard particles and the debonding damage.