Design of an Impact Ram Used to Simulate Loadings Encountered During Automobile Accidents

Abstract

In tests used to assess the impact biofidelity of anthropomorphic test dummies (ATD), post mortem human specimens (PMHS) are impacted with a ram to simulate the loadings that occur during automobile impacts. Other tests require the ram to impact the ATD for calibration and verification. The current pneumatic impact ram in the Injury Biomechanics Research Lab (IBRL) has become obsolete primarily because of the inability to accurately control the velocity of the ram as it impacts the subject. Because of the inaccurate and unpredictable nature of the current ram, redundant and expensive tests may be required on an already limited supply of PMHS. Other issues have also become prevalent such as the long changeover period of the ram face and mass when different tests are to be conducted on the same subject, consuming precious time by allowing the cadavers to further degrade. In other cases, the angle of the camera equipment must be adjusted relative to the ram during impacts at an angle when ideally; the ram would adjust relative to the camera equipment because of the confined space. It is the objective of this research project to: - Determine design requirements of a new ram to achieve impacts at a constant velocity given varying impact ram mass and velocity requirements of current ATD and PMHS tests [1] - Determine the instrumentation to measure the displacement, velocity, acceleration, and force of the ram, and to consider the possibility of adjusting the height, the angle of impact, and the mass/face of the ram - Design and document a new impactor to meet the agreed upon design requirements