The Effect of Limiting Impact Force on Abdominal Injury: A Preliminary Study

This report describes a series of experiments using Hexcel(TM) to limit the impact force in lateral abdominal impacts. Two hundred fourteen (214) anesthetized New Zealand White rabbits were impacted at 5 to 15 m/s using a pneumatic impactor. Injury responses from tests with a force-limiting impact interface (94 tests) were compared with the responses from tests with a rigid impact interface (120 tests) having the same level of lateral abdominal compression. The Hexcel had a length of 3 inches, the same diameter as the rigid impactor, and crushed at a constant force (pressure level of 232 kPa (33 psi)) once deformation was initiated.

The results of these tests showed that the probability of serious abdominal injury did not change significantly with the Hexcel, even though peak pressures were reduced to as little as one third of their previous values. The overall abdominal injury severity was dominated by hepatic injuries which remained as severe with Hexcel as the interface, although the probability of sustaining a renal laceration was three times lower with Hexcel. As seen in previous studies, the biomechanics of soft tissue injury appear to be dominated by the Viscous response.