Dynamic perforation and force measurement for lightweight materials by reverse ballistic impact

A new technique to compare the resistance of different light weight materials such as high performance fibre fabrics, polymers or light metals against dynamic perforation, is presented. A reverse Hopkinson bar impact test is used to measure the impulse carried away from the impact zone. In cooperation with a leading textile research institute, different composite materials based on phenolic resin and special flat weft knitted aramid-fabrics or woven aramid-fabrics have been characterized by this new technique. The target material is accelerated with a carrier against the stationary penetrator having the desired nose shape. The advantage this technique offers over standard impact tests is the recording of a resulting force–depth of penetration history useful for classifying the tested materials. This allows one to gain further understanding of the failure mechanisms of the material during the penetration event. The experimental set-up, and the measurement and evaluation methods are presented together with the results of tests of textile-based panels at an impact velocity of 230 m/s. For comparison, the results of tests of several commercial polymers and a metal are presented as well.