High rate crushing of wood along the grain

The results of tests carried out to measure proximal end and distal end loads during dynamic crushing of oak along the grain over a velocity range of 20-260 m/s are presented. A stress enhancement factor of roughly 2 is seen in the distal end loads for impact velocities from 34 to 225 m/s. Further enhancements in stress measured at the proximal end are the result of inertia effects associated with the dynamic localisation of crushing. The crushing behaviour is analysed using shock wave theory together with rigid, softening, hardening and elastic, softening, hardening material models. The results of the analyses compare well with load histories recorded experimentally.