Ballistic response of skin simulant against fragment simulating projectiles

The response of biological phantoms against high velocity impact is actively sought for applications in defense, space, soft robotics and sensing. Towards this end, we study the ballistic response of silicone based skin simulant against fragment impact. Using a pneumatic gas gun setup, six chisel-nosed and three regular shaped (sphere, cylinder, and cube) fragments were impacted on the skin simulant. The resulting skin simulant response was studied in terms of ballistic limit velocities, energy densities, failure pattern, and the mechanics of interaction. The results indicate that the shape of the fragment affects the ballistic limit velocities. The ballistic limit velocities, energy densities of the chisel-nosed fragment simulating projectiles were relatively insensitive to the size (mass), except for the smallest (0.16 g) and largest (2.79 g) chisel-nosed fragment. For the same size (1 g), ballistic limit velocities and failure are dependent on the shape of the fragment. The skin simulant failed by combined plugging and elastic hole enlargement. Failure in the spherical fragment was dominated by the elastic hole enlargement, whereas plugging failure was dominant in all other fragments. The spherical, cylindrical, and chisel-nosed fragments created circular cavities, and the cubical fragment created a square cavity. In the case of the spherical fragment, slipping of the fragment within the skin simulant was seen. Cubical fragments created lateral cracks emanating from the corners of the square cavity. Interestingly, for all the fragments, the maximum deformation corresponding to the perforation was lower than the non-perforation indicating rate dependent, stress driven failure. The maximum deformation was also dependent on the shape of the fragment. Overall, these results provide unique insights into the mechanical response of a soft simulant against ballistic impact. Results have utility in the calibration and validation of computational models, design of personal protective equipment, and antipersonnel systems. (c) 2023 China Ordnance Society. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).