Axial impact driven buckling dynamics of slender beams

Abstract

We present experiments on the dynamic buckling of slender rods axially impacted by a projectile. By combining the results of Saint-Venant and elastic beam theory, we derive a preferred wavelength for the buckling instability, and experimentally verify the resulting scaling law for a range of materials using high speed video analysis. The scaling law for the preferred excitation mode depends on the ratio of the longitudinal speed of sound in the beam to the impact speed of the projectile. We will briefly present the imprint of this deterministic mechanism on the fragmentation statistics for brittle beams.