Impact of steel spheres on ballistic gelatin at moderate velocities

We study experimentally and computationally the penetration of a steel sphere into a block of ballistic gelatin for developing an improved understanding of the damage caused to human soft tissues when impacted by a blunt object moving at a moderately high speed. The gelatin is modeled as an isotropic and homogeneous elastic plastic material that exhibits linear strain-hardening and obeys a polynomial equation of state. Pictures taken by a high speed camera help construct the tunnel formed in the gelatin that is found to compare well with the computed one. Furthermore, computed time histories of the pressure at a point agree well with the corresponding experimentally measured ones for small times. The computed time histories of the temporary cavity size agree well with the corresponding experimental ones. These agreements between test findings and computed results imply that the computational model can reasonably well predict significant features of the impact event. Effects of impact velocity and sphere diameter on damage caused to the gelatin have also been studied. (C) 2013 Elsevier Ltd. All rights reserved.