A finite-deformation constitutive model of particle-binder composites incorporating yield-surface-free plasticity

Abstract We present a constitutive model for particle-binder composites that accounts finite-deformation kinematics, nonlinear elasto-plasticity without apparent yield, cyclic hysteresis, and progressive stress-softening before the attainment of stable response. The is based on deformation mechanisms experimentally observed during quasi-static monotonic compression mock Plastic-Bonded Explosives (PBX) at large strain. An additive decomposition strain energy into elastic inelastic parts assumed, where response modeled using Ogden hyperelasticity while described yield-surface-free endochronic plasticity concepts internal variables evolution or rate equations. Stress-softening two approaches; discontinuous isotropic damage to appropriately describe softening in overall loading-unloading response, material scale function until stabilization. A multivariate optimization procedure developed estimate elasto-plastic parameters from nominal stress-strain experimental data. Finally, correlation between unique PBX specimens with differing concentrations aluminum identified, thus establishing relationship composition.