INCREMENTAL DAMAGE THEORY AND ITS APPLICATION TO GLASS-PARTICLE-REINFORCED NYLON-66 COMPOSITES

This paper deals with influence of particle volume fraction and debond ing damage between particles and matrix on the stress-strain response in particle-reinforced ductile matrix composites. Tensile tests are ca rried out on seven kinds of glass-particle-reinforced nylon 66 composi tes, which are different in a particle volume fraction and treatment o f interface between the particles and matrix. The stress-strain respon se of the composites depends on both the particle volume fraction and the interface treatment. Young's modulus and Poisson's ratio are chara cterized 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 increas es first and then becomes constant in the interface-treated composites , and decreases in the interface-untreated-composites. Numerical analy ses of the stress-strain response and damage behavior of the composite s are carried out based on an incremental damage theory which describe s the plasticity of the matrix and the debonding damage. The stress-st rain relations of the interface treated composites are characterized o nly by influence of particle volume fraction while those of the interf ace-untreated composites are explained by considering the particle vol ume fraction and interfacial debonding. (C) 1997 Published by Elsevier Science Ltd.