Incremental damage theory and its application to glass-particle-reinforced nylon 66 composites

Abstract

This paper deals with influence of particle volume fraction and debonding damage between particles and matrix on the stress-strain response in particle-reinforced ductile matrix composites. Tensile tests are carried out on seven kinds of glass-particle-reinforced nylon 66 composites, which are different in a particle volume fraction and treatment of interface between the particles and matrix. The stress-strain response of the composites depends on both the particle volume fraction and the interface treatment. Young's modulus and Poisson's ratio are characterized by only the particle volume fraction, while tensile strength depends on both the particle volume fraction and interface treatment. With increasing particle volume fraction, the tensile strength increases first and then becomes constant in the interface-treated composites, and decreases in the interface-untreated composites. Numerical analyses of the stress-strain response and damage behavior of the composites are carried out based on an incremental damage theory which describes the plasticity of the matrix and the debonding damage. The stress-strain relations of the interface treated composites are characterized only by influence of particle volume fraction while those of the interface-untreated composites are explained by considering the particle volume fraction and interfacial debonding.