Localized Structural Instability and Dynamic Strength of Brittle Materials

Four brittle materials are subjected to shock tests: gabbrodiabase, two modifications of cast iron, fused quartz, and beryllium. An interferometer is used to locally probe a free surface in order to calculate its velocity, thereby determining the criterion of the initial stage of brittle fracture of all materials tested—the formation of horizontal steps at the forefront of a compression pulse, which indicate the presence of local sources of fracture of the material. It is determined that the brittle material resists the shock compression as long as it has the reversible transfer of momentum and energy of the processes occurring at meso- and macrolevels.