Mesocale mechanisms and non-linear behaviour of propellant-like particulate composites. Experiment and modelling

Evaluation of engineering vulnerability of energetic aggregates, e.g. against accidental impacts, requires precise, quantitative assessment of the salient mechanisms of deformation and damage on the mesoscale level. This allows in turn further study of constitutive behaviour linking the complex dissipative response to its underlying physical background. In the present paper the viscoelastic-plastic and damage response of a class of propellant-like particulate composites is studied. The material is composed of a high percentage of crystalline charge embedded in an elastomeric binder matrix. After summarizing preponderant experimental features concerning mesoscale mechanisms and macroscopic stress-strain behaviour, a viscoelastic-plastic phenomenological model is outlined and discussed. By way of conclusion the new micromechanical approach involving viscoelasticity and damage is commented.