Secant Moduli of a Glass Bead-Reinforced Silicone Rubber Specimen

Abstract

The influence of volume-fraction of inclusions on the overall stress-strain of a rubber-matrix composite is investigated at the level of dilute concentration. The method developed is based on the approximate mean-field theory developed by Weng and coworkers for plasticity of two-phase composites (Tandon and Weng, 1988; Zhao and Weng, 1989; Qiu and Weng, 1992), using Berveiller-Zaoui's (1979) approximation approach. The constraint due to the matrix phase is characterized by the secant moduli of the matrix, while the interaction of the inclusion is accounted for by the Mori-Tanaka mean-field theory. It is shown that this simple, but approximate theory is capable of predicting the volume fraction dependence of the nonlinear stress-strain relation. An asymptotic solution for this composite system is obtained. By introducing a nonlinear stretch parameter λ _m and a stress parameter λ _m the stress-stretch master curve of the hardbead-reinforced silicone rubber composite is obtained. The theoretical predictions are in good agreement with the experimental results.