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 a nd matrix on a crack-tip field in a glass-particle-reinforced nylon 66 comp osite. In order to explain the influence of debonding damage on the fractur e toughness, numerical analysis of a crack-tip field was carried out on the interface-treated and untreated composites by using a finite element metho d developed on the basis of an incremental damage theory of particle-reinfo rced composites. At the crack-tip region, the damage zone due to the partic le-matrix interfacial debonding develops in addition to the plastic zone du e to matrix plasticity. The damage development around a crack-tip depends o n the interfacial strength between particle and matrix and the particle vol ume fraction. It is found that the debonding damage reduces the stress leve l around a crack-tip and acts as the toughening mechanism. The mechanical p erformance of particle-reinforced composites is obtained as a result of the competitive effects of the intact hard particles and the debonding damage.