Energy absorption of truncated Kevlar epoxy cones under off-axis loads

A total of 27 Kevlar/epoxy truncated cones was manufactured and crushed und er off-axis loads. Side loads were introduced by cutting the cones at angle s relative to their central axes. The failure modes were observed, and the specific sustained crushing stresses were determined and compared against g raphite/epoxy cones of the same lay-up and similar geometry. The Kevlar/epo xy cones exhibited significantly different failure modes than the graphite/ epoxy cones. Specifically, the cones did not experience brittle fracture, a nd thus maintained structural integrity after crushing. The Kevlar/epoxy co nes were less sensitive to the angle of the applied load than similar graph ite/epoxy cones; however, the energy absorbed per unit mass is significantl y lower. The role of specimen taper and load inclination is different than that for graphite/epoxy cones. In particular, 10 degrees tapered cones over all had the best performance even under uniaxial loading conditions.