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The shear strength of a ceramic is an important material property which is indicative of its behaviour under impact loading condition, The brittle nature of ceramics suggest that impact loading of a ceramic attained due to subsonic impact could change the initial shear strength of the ceramic. If so, the subsequent behaviour of the ceramic may not be dependent on the the initial strength. Thus, it is necessary to determine the shear strength of a cermaic under single and multiple impacts. The present work determines the change in the shear strength of silicon carbide under a single shock, shock-reshock, and shock-release wave propagation, respectively. The material used in this work is marketed by CERCOM Inc. as SiC-B. The results of this work indicate that shear strength of SiC-B increases under shock-reshock.

The present work describes the compression and release response of a glass-fiber-reinforced polyester composite (GRP) under shock loading to 20 GPa. Shock experiments in GRP were performed at Sandia National Laboratories and the US Army Research Laboratory. GRP is a heterogeneous material. The diagnostic measurements fluctuate beyond the precision of the experimental measurements but they do permit determination of an average response of the material at the end state. These experiments show that: (i) GRP deforms elastically in compression to at least 1.3 GPa; (ii) the deformation coordinates of shocked and re-shocked GRP lie on the deformation locus of initially shocked GRP to 4.3 GPa; (iii) and the release path of GRP shocked to varying magnitudes of stresses indicate that the GRP expands such that its density when stresses are released in the range of 3–5 GPa from a peak compressive stress of 9 GPa and above is lower than the initial density of GRP. Possible reasons for the observed lower density remain to be investigated.

This work compares the estimates of shear strengths of aluminium nitride and titanium diboride obtained (a) from the simultaneous measurements of longitudinal and lateral stress by means of manganin gauges under plane shock wave loading with (b) those calculated from the offset between hydrodynamic and shock Hugoniot of these materials. The results of this work show that whereas the estimates of the shear strength obtained by these two methods for titanium diboride are consistent with one another, those of aluminium nitride are not. This is at least partly due to the observed inconsistency between the simultaneous measurements of longitudinal and lateral stresses in aluminium nitride.

The pressure derivatives of the elastic constants of single-crystal Ni 3 Al have been determined to 1.4 GPa by both pulse super-position and pulse-echo overlap techniques. Measurements were made on single-crystal specimens of orientation 〈100〉 and 〈110〉, thus providing at least one cross check. The values of c 11 , c 12 , and c 44 at one atmosphere are found to be 223.5, 149.0, and 122.9 GPa, respectively.

Model simulation of double shock-release experiments in PMMA was performed using DYNA2D and KOH codes. Calculated wave profiles in both the elastic and inelastic ranges of peak stress were in good agreement with experimental profiles measured using commercial manganin gages.