Studying the mechanical response of particle-reinforced polymer composites to dynamic loadings has led to a better understanding of reactions observed for energetic materials from insults well below their shock-initiation threshold. Uniaxial stress and uniaxial strain experiments were conducted at strain rates ranging from quasistatic to 104 sec-1 for a highly filled, HTPB-based, cast-cure, explosive simulant. Analysis of samples recovered from high strain-rate confined compression tests evidenced the fracture of the particulate filler in some of the items. Furthermore, the parameters derived from these experiments, along with a series of numerical simulations using a two-dimensional hydrocode, were used to derive a macroscopic material model consisting of a nonlinear viscoelastic equation of state with linear viscoelastic deviatoric components. This model was validated using inverse impact experiments of "explosive"-filled penetrators and further exercised in simulations of generic explosive-filled penetrators impacting hardened targets at various velocities. Such a model is also a valuable tool for studying the response of propellant and explosive-filled hardware in accident scenarios which might occur during transport and handling.
John Corley
Fraunhofer EMI viskoelastisches Modell Verbundwerkstoff energetischer Stoff dehnratenabhängiges Verhalten Impaktsimulation Viskoelastische Modelle Verbundwerkstoffe Energetisch Stoffe Dehnratenabhängiges Verhalten Impaktsimulation