Modeling Nonpenetrating Ballistic Impact on a Human Torso

Abstract

When soldiers or law enforcement officers are shot in the chest or abdomen there may be internal injuries even though a soft armor vest prevents penetration of the projectile. This nonpenetrating injury could remain undetected until the person succumbs, for instance, to hemorrhaging in the lungs or laceration of the liver. In addition, tools are needed to design more effective soft armor vests that are lightweight, are flexible enough to fit the body contour, and can defeat high-velocity rifle rounds. To study internal organ injuries and design better vests under nonpenetrating ballistic impact, both a computational (finite element) model (FEM) and a physical human surrogate torso model (HSTM) have been developed. These models consist of the heart, lungs, liver, and stomach surrounded by the skeleton. The HSTM was outfitted with a soft armor vest, and ballistic tests were conducted using 9-mm ammunition at various velocities. While the peak accelerations and peak pressures from the FEM did not match those from testing, the trends and patterns were similar. These results represent a significant step in developing an understanding of the deformations and energy transfer characteristics of ballistic impacts through personal body armor.