EXPERIMENTAL SYSTEMS FOR IMPACT PROTECTION

Abstract : The impact absorbing properties of starch/brine dilatant suspensions were characterized with an instrumented, pendulum-type impact tester. The starch concentrations were varied between 47.5 and 52.5% and sealed in heavy rubber bags of varying thickness. The temperature of the filled rubber bags was varied between 45 and 110F. Impacting energies ranged between 30 and 141 ft-lbs with velocities of 11 and 17 ft/sec. The dilatant suspensions were found to be highly efficient and reusable energy absorbers under all test conditions. Impactor penetration, peak deceleration, and jerk varied depending on the impact energy input, impact velocity, bag wall thickness, and, to a lesser extent, starch concentration and temperature. The filled bags readily conform to the shape of a 1 cm radius impactor and yield relatively low peak deceleration and jerk. There was no noticeable deterioration of the dilatant properties as a result of temperature cycling and repeated impacts.