Micromechanical analysis of the nonlinear elastic and viscoelastic constitutive relation of a polymer filled with rigid particles

Micromechanical theory was applied to study the nonlinear elastic and viscoelastic constitutive relations of polymeric matrix filled with high rigidity solid particles. It is shown that Eshelby's method can be extended to the case of nonlinear matrix and Eshelby's tensor still exists provided that Poisson's ratio of the nonlinear matrix assumes constant value in deforming process and the rigidity of elastic filling particles is much higher than that of the matrix. A new method for averaging process was proposed to overcome the difficulty that occurs in applying the ordinary equivalent inclusion method or the self-consistent method to nonlinear matrices. A rather simple constitutive equation was obtained and the strengthening effect of solid particles to composites was investigated.EI02176-1851