A Numerical Study of Cavitation and Yield in Amorphous Polymer-Rubber Blends

A numerical study is presented of cavitation and yield in amorphous polymer-rubber blends in terms of a unit cell model involving an initially voided rubber particle. The particle is described by a non-Gaussian rubber elasticity model, while the glassy matrix is described by a material model featuring time-dependent yield, followed by intrinsic softening and subsequent strain hardening. Large strain, finite element analyses are reported which give a detailed view on the growth of the void in the rubber particle in concurrence with progressive plastic deformation in the matrix. The study focusses on the effect of the rubber particle properties on the growth of the initially cavitated particle. The results indicate that below a certain value of the rubber modulus, the particle behaves as a void, whereas above that value the rubber will tend to increasingly suppress plasticity and void growth.