  CEA-Gramat studies the sensitivity of energetic materials to enhance their
security and reliability. The conditions leading to the initiation of an
explosive must be understood to control its sensitivity. According to the hot
spots theory, the shock initiation of heterogeneous explosives is related to
their microstructure: the shock interacts with the heterogeneities of the
microstructure (pores and inclusions, morphology of grains and fragments,
debonding, etc.) and creates local deposits of energy. To describe these hot
spots, energetic materials have to be modeled at a scale allowing the
discretization of their microstructure: the mesoscale. Micro-computed
tomographies of energetic materials are done at CEA-Gramat and analyzed to
build geometric models used in finite element simulations. Two kinds of models
are studied:-Real models are directly built on the real microstructures
extracted from micro-computed tomographies.-Virtual models are based on the
same microstructures but simplified to study independently the effects of
microstructural parameters (granulometry, porosity, filler content{\ldots}) on
the creation of hot spots. Compositions based on different kind of RDX
particles in an inert binder are studied through numerical simulation. The
influence of particle shape on the inert shock response is investigated at the
mesoscale. Local heterogeneities of pressure and temperature fields appear
intimately related to the morphological properties of the microstructures.
Particles with sharp edges create more hot spots than spherical particles.
