USE OF A BERYLLIUM HOPKINSON BAR TO CHARACTERIZE A PIEZORESISTIVE ACCELEROMETER IN SHOCK ENVIRONMENTS

The characteristics of a piezoresistive accelerometer in shock environ ments are being studied at Sandia National Laboratories in the Mechani cal Shock Testing Laboratory. A Hopkinson bar capability has been deve loped to extend our understanding of the piezoresistive accelerometer, in two mechanical configurations, in the high-frequency, high-shock e nvironments where measurements are being made. In this paper the beryl lium Hopkinson bar configuration with a laser doppler vibrometer as th e reference measurement is described. The in-axis performance of the p iezoresistive accelerometer for frequencies of dc-50 kHz and shock mag nitudes of up to 70,000 g as determined from measurements with a beryl lium Hopkinson bar are presented. Preliminary results of characterizat ions of the accelerometers subjected to cross-axis shocks in a split b eryllium Hopkinson bar configuration are presented.