High Pressure Shock Wave Attenuation

The attenuation of high pressure shock waves has been investigated. High purity copper, 6061-T6 aluminum, 6A1-4V and a phase titanium, an uranium alloy and two alloys of beryllium were examined experimentally at pressures as high as 3 megabars. Low pressure experiments were instrumented with a velocity laser interferometer. Intermediate pressures (to several hundred kilobars) were instrumented with manganin wire peizoresistive gages and high pressure measurements were made through observation of free surface velocities. The results show that evidence of strength, as exhibited by elastic release wave behavior, persists to pressures of hundreds of kilobars and that the release wave structure is not elasticperrectly plastic. For the materials examined the release wave structures can be described as exhibiting a Bauschinger effect. For megabar pressures (beyond melting behind the shock front) fluid behavior is indicated by the lack of an elastic release wave.