TAPERED GEOMETRIES FOR IMPROVED CRASHWORTHINESS UNDER SIDE LOADS

Truncated cones of varying degrees of taper are manufactured from unidirectional AS4/3501-6 graphite/epoxy preimpregnated tape and are loaded in compression. Different amounts of side loads are introduced by orienting the loading axis away from the central axis of the cone. The energy absorption properties of the cones are measured under quasistatic conditions. The failure modes are determined around the circumference as a function of the loading and taper angles, and the energy absorbency is correlated to the observed failure modes. Constant crosssection specimens suffer significant losses in energy absorption in the presence of side loads; however, tapered specimens are less sensitive and do not suffer such significant losses. In fact, tapered geometries provide greater energy absorption than constant crosssection geometries at moderate levels of side loads.