Instrumented Projectiles for Measuring Impact Forces to Characterize Ballistic Behavior of Fabrics and Composites

In order to simulate the high velocity involved in ballistic impacts, at least up to some extent, laboratory used gas guns have been developed for material and structure testing. However, if the projectiles of the guns are not instrumented, they cannot provide information concerning impact mechanisms and damage processes during impacts. In an effort to improve their measuring capability, accelerometers may be added to the gun projectiles. Besides, due to the small dimensions, large deformation and high frequency involved in ballistic impacts, difficulties in extracting impact mechanisms and damage processes will continue to exist. Strain gage based high-velocity ballistic impactors are very different from strain gage based low-velocity drop-weight impactors. The former are based on strain wave propagation while the latter deformation. Many more challenges are expected to encounter in the development of high-velocity instrumented ballistic impactors than that in the low-velocity drop-weight impactors. However, the reward of an instrumented ballistic impactor will be enormous. It can help to improve the understanding of the impact mechanisms involved in ballistic impacts and the damage processes occurred in the impacted specimens. Hence, the design of composite materials and structures for combating ballistic impacts can be greatly accelerated.