Characteristics of acoustics emission signals produced by hypervelocity impact

A two-stage light gun was used to fire different diameter spherical aluminum ball at various impact velocities to aluminum panels, which more closely simulated damages caused by hypervelocity impacts of micrometeoroids and space debris on spacecraft. The AE impact signals were recorded by an oscillograph with AE sensors. In order to separate the characteristics of different wave modes, the AE signals were divided into low frequency and high frequency parts by wavelet time-frequency transform and reconstruction. The results show that the peak values of the impact signals can be represented the damage condition of the spacecraft. The empirical equations between the impact depth, the diameter of the impact crater and the peak values are given.