In this paper, we study the shock compressibility and spall strength of composites reinforced with carbon fibers and glass fibers using a VISAR laser interferometer. A two-wave configuration is shown to form in both composites during the propagation of a shock wave along the fibers. The two-wave configuration in fiberglass is observed up to a shock-compression pressure of 18 GPa while in a carbon-fiber reinforced polymer (CFRP), it is recorded in the entire studied range of pressures up to 33 GPa. The Hugoniots and spall strength of composites were determined at various fiber orientations.

A VISAR multipoint laser interferometer is used to study a detonation wave structure in mixtures of tetranitromethane with methanol and nitrobenzene. A poor reproducibility of particle velocity profiles is observed in different experiments with a fixed composition of mixtures. As shown by simultaneous recording of wave profiles at several points of the detonation front and different cross sections of the sample, the flow is one-dimensional and stable with respect to longitudinal perturbations. This means that steady detonation is observed in each experiment, and its parameters differ from shot to shot. Aside from the lack of reproducibility of particle velocity profiles, nonclassical detonation is recorded in the mixtures under study, which is observed as the absence of a von Neumann spike in a reaction zone. A possible relationship between these two phenomena is discussed.

Investigation of shock-wave compressibility of three anisotropic materials (carbon fibre reinforced plastic, textolite and kevlar) was performed by a VISAR laser interferometer. Two of these composites consist of the same aramid fibers (textolite and kevlar) and two of them have the same structure (CFRP and kevlar). The structure of compression pulse and shock wave velocity of materials were obtained in each experiment. The shock wave structure in tested composites significantly depends on the fibers orientation - a two-wave configuration is recorded in almost the entire range of studied pressures when shock wave propagates along the fibers. Hugoniot parameters of anisotropic materials were obtained in the coordinates of the shock wave velocity D – particle velocity u for two orientations of the fibers. Hugoniots of kevlar, textolite and CFRP with perpendicular orientation of the fibers are parallel to each other. For kevlar and CFRP, the shock wave compressibility almost does not depend on the fibers orientation relative to the direction of the shock wave propagation. In textolite with parallel orientation of the fibers, the shock compressibility is determined by the properties of unidirectional aramid fibers, and Hugoniots for two directions differ significantly.

An experimental study of the reaction zone structure and stability of detonation waves was performed for tetranitromethane–methanol (TNM–M) mixture using a velocity interferometer system for any reflector (VISAR). At the near stoichiometric concentration of methanol, it was observed that the amplitude of Von Neumann spike decreases significantly, whereas the detonation parameters increase. The instability of detonation waves in TNM–M mixture was shown, both with respect to one-dimensional longitudinal perturbations and to the curvature of the front leading to the formation of the cellular structure. The dependence of detonation velocity of TNM–M on the diluent concentration and limits of detonation propagation were found.

The experimental study of shock wave compressibility and spall strength of an aramid fiber reinforced epoxy composite (textolite) for two fiber orientations was performed by the VISAR interferometer. The particle velocity profiles were obtained at velocities of the flyer plate from 0.65 to 5.05 km/s. The sound speed of textolite for the longitudinal direction is three times higher than that for transverse one, and as a result, the particle velocity profiles are different for two orientations. For the transverse direction of the fibers, a single shock wave is observed, while for longitudinal one, a two-wave configuration is recorded up to 20 GPa. Hugoniot parameters for both orientations of the fibers were found up to 35 GPa: D = 2.37 + 1.26 ∗ u – for transverse one and D = 1.45 + 2.05 ∗ u – for longitudinal, where D is the shock wave velocity and u is the particle velocity. The spall strength of textolite is equal to 61 MPa for shocks traveling along the fibers, and this is almost twice higher than that for the transverse direction.