Shock-initiation and Detonation Extinction in Homogeneous or Heterogeneous Explosives: Some Experiments and Models

Chemical explosives can be found in the gaseous, liquid or solid phases but it is customary to distinguish homogeneous explosives from heterogeneous ones. Indeed experiments have revealed that the dynamical behaviors of detonative or quasi-detonative decomposition regimes of explosives have more to do with the latter classification than with the former. However, distinguishing between homogeneous and heterogeneous behaviors can be questionable depending on the nature, the amplitude or the range of the solicitation applied to the considered explosive. The objective of the presentation is to report on some recent modeling of critical dynamical behaviors of homogeneous or heterogenous explosives in conditions of chemical decomposition close to the detonation regime. The approaches are based on continuum and micromechanical models. The first part of the presentation will be devoted to the shock-to-detonation transition (SDT) in homogeneous materials, the second one to detonation critical diameters of heterogeneous materials. Each part will be preceded by a short review of experimental facts. The choice is to relate modeling and experiments by means of as simple as possible assumptions, yet mathematically and physically consistent with the underlying dynamics of the phenomena.