Effect of Impact Rate in Multiple Impacts on Aramid Fabrics

Single ballistic impact tests are commonly being used for determining the level of protection against fragment impacts such as those generated from devices containing high explosives. These methodologies suggest that the interactions between multiple fragment impacts are negligible. A triple ballistic impact technique is proposed in order to simulate the conditions of a dense cluster impact on a protective structure such as primary and secondary fragments from an explosive device impacting the Personal Protective Equipment (PPE) of a deminer. Triple and single impact tests were performed against 15layer of plain weave aramid fabric square specimens fully clamped. A detailed yarn based FE numerical model utilising LS-Dyna® package was developed and cross-referenced with the experimental data. The same aramid model was used to investigate multiple impact scenarios with variant impact rates.