Experimental characterization and continuum modeling of inelasticity in filled rubber-like materials

Filled rubber-like materials are important engineering materials, and they are widely used in aerospace, automotive, and other industries. However, their nonlinear, inelastic, and rate-dependent constitutive behavior is not fully understood and modeled with varying degrees of success. Much of the previous literature has focused on either capturing quasi-static stress-softening behavior or rate-dependent viscous effects, but generally not both concurrently. In this work, we develop a thermodynamically consistent constitutive model which accounts for both of those phenomena concurrently. A set of comprehensive mechanical tensile tests were conducted on the filled rubber Viton. The constitutive model was then calibrated to the experimental data, and numerically implemented into the finite element package Abaqus by writing a user material subroutine UMAT. The constitutive model was validated by comparing a numerical simulation prediction with an inhomogeneous deformation experiment.