Impact characteristics of energy absorbing materials for radioactive material transport packages

A series of high-velocity impact tests using grout as the package energy-absorbing material was successfully carried out. The purpose of these tests was to characterize the dynamic behavior of grout material when used as an energy-absorbing material for packages. These package-impact tests were simulated accurately with the dynamic finite element code DYNA, using appropriate grout material properties. The need to invoke the grout damage curve illustrates the fact that the grout mix under study undergoes a transition where the grout retains its full strength at relatively low impact velocity to a diminished strength where progressive debonding and pulverization takes place as the impact velocity increases. The transitional velocity range is a function of a particular grout mix as well as impact conditions. Laboratory tests of the grout mix that include the failure region and different failure modes should be an integral part of the investigation process to accurately correlate package benchmark tests with analytical models. (J.P.N.)