Dynamic elastic buckling loads of slender rods and their dependence on geometrical features of specimens at intermediate impact velocities

Abstract
In this research, dynamic buckling behaviors of column- and plate-type long aluminum rods were investigated both experimentally and numerically. In the experiments, a free fall drop-weight type impact testing machine was employed, and dynamic loads of up to buckling points were measured precisely by means of the load sensing block method. In the numerical analyses, dynamic FEM code ‘MSC-Dytran’ was used to simulate dynamic buckling behavior, and the validity and the accuracy of the simulation were checked through comparison with experimentally obtained load-time and displacement-time diagrams. The dynamic buckling loads at various impact velocities were, then, systematically investigated. From both experimental and simulated results, an effective empirical criterion for dynamic buckling of both types of rods was derived in terms of the impact velocity and the slenderness ratio. It was found that parameters in the equation to describe the dynamic buckling criterion for column- and plate- type rods take very close values, and this fact implies that the geometrical effect on dynamic buckling load ratio may be not so significant as far as the slenderness ratio is taken into account as a certain geometrical scale.