Sensitivity Study of the HUSKY PUP Granite Block Experiment.
Final rept. Aug 76-Feb 77,
CALIFORNIA RESEARCH AND TECHNOLOGY INC WOODLAND HILLS
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A series of 1-D calculations simulating the impact of the flyer plate on the granite block in the HUSKY PUP experiment was made to evaluate the effects of equation of state EOS modeling, energy levels and distributions, and numerical parameters on the resulting time of arrival TOA of the shock wave at stations in the block. This objective was to provide a basis for judging the significance of comparisons between TOA vs depth measurements and results of more complex 2-D pretest calculations of the event. The total energy in the flyer plate and block prior to impact was found to be the single most important factor affecting the TOA. Distribution of energy was of secondary importance internal energy was found to have an effect equivalent to that from about 34 of the same quantity of kinetic energy. Eight EOS models for granite were considered. Despite considerable differences in the Hugoniots and release adiabats in these models, the maximum effect of the models on the TOA vs depth curves was equivalent to only a 30 percent change in the flyer plate energy which presumably directly reflects the source energy. Variations in other parameters, including computational zone size, artificial viscosity, and flyer plate density, had negligible effects on the TOA over the ranges considered. These 1-D results indicate that TOA vs depth calculations are relatively insensitive to any parameter or uncertainty other than the total energy in the flyer plate-granite block system.