Taylor-impact experiments for brittle ceramic materials

A new time-resolved test methodology is described which allows access to loading rates that lie between split Hopkinson bar and shock-loading techniques. Gas-gun experiments combined with velocity interferomtry techniques have been used to experimentally determine the intermediate strain-rate loa ding behavior of Coors AD995 alumina, Cercom silicon-carbide and Cercom boron-carbide rods. Graded-density materials have been used as impactors; thereby eliminating the tension states generated by the radial stress components during the loading phase. Results of these experiments demonstrate that the time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial-strain loading to a uniaxial-stress state as the stress pulse propagates through the rod. This allows access to intermediate loading rates over 5 x 10(3)/S to 10(6)/S.