Stress-strain response and volume change of a highly filled rubbery composite: experimental measurements and numerical simulations

The stress-strain response of a rubbery polymer network highly filled with micrometric glass beads was measured at low strain rate in uniaxial tension. The volume change of the glass bead filled material upon stretching was recorded by video extensometry and X-ray tomography scans were used to identify the type of damage within the composite material. The modeling used a cohesive-zone model from the literature depending on the polymer/glass adhesion energy that was measured by peeling polymer strips from a glass plate. Nonlinear finite element simulations were performed on representative three-dimensional microstructures defined by periodic cubic unit cells containing randomly dispersed spherical particles}. Good reproductions of both the composite response and the volume change were obtained prior to the appearance of inner cracks