Acoustic response of aluminium and Duroid plates to hypervelocity impacts

The growing need for real-time impact sensors for deployment on both space vehicles and space habitats (in orbit or on the surface of atmosphere-less bodies such as the Moon) has stimulated sensor development programmes. The sensors should be low mass, low power, easily read-out electronically, cover large areas and be sensitive to impacts which can cause damage up to and including penetration. We propose that piezo-strain acoustic sensors can play an important role in this work. Accordingly we report on a series of hypervelocity impact tests of acoustic sensors mounted on thin plates (aluminium and Duroid plates). The acoustic sensors gave strong signals for impacts of sub mm–mm scale projectiles. We investigated dependences on impactor speed and size, angle of incidence and tested the difference between cratering and penetrating impacts.