A NOVEL AIR GUN AND ITS APPLICATION IN ANTI-HIGH G SHOCK ABILITY OF MEMORY MEASUREMENT EQUIPMENT

摘要

In this paper, a kind of novel air gun which had been developed by our laboratory is presented. It is different from normal air gun which makes use of pressured air or nitrogen and hydrogen to push projectile to impact target, then observe the penetration effects. By the novel air gun, the shell shot is pushed with pressured air to impact the on-board memory test equipments (OBMTE) or the mounted base of accelerometers, an acceleration impulse with 100～200 micro-seconds duration and up to 15×104 g amplitude had been obtained by controlling air pressure and the thickness and capability of felt. The air gun, two sets of grating Laser Doppler interferometer and other measurement apparatus together compose of the high g shock calibration and test system. With the system, the following researches should be performed: First, the high g accelerometer can be directly and absolutely calibrated, and shock acceleration value is acquired from the base quantity and unit(time and length). Second, the zero-shift mechanism of the piezoelectrical-type accelerometer is studied. Third, the anti-high g shock ability and failure mechanism of memory measurement equipments can be researched. Last, the buffering protection methods for the recorded circuit modules had been investigated with the shock test system. The aluminum foam with different capability and rubber had been used to protect circuit modules, and finite element software ANSYS-LS-DYNA had been used to simulate the buffering effect of aluminum foam. By the application of air gun system, the parameter of accelerometer and on-board memory test equipments can be evaluated before field test of projectile penetrating hard target, so the potential failure risk will been reduced and the ratio of obtaining test acceleration datum signal will be improved.