Estimation of the initial peak load for circular tubes subjected to axial impact

This paper discusses the estimation of the initial peak load for circular tubes subjected to axial impact based on a finite element analysis. The peak load depends on the material properties, tube geometries and impact velocity. By changing some parameters systematically, effects of material properties and tube geometries on the peak load are explored. Also, the effect of the impact velocity on the peak load implies both the inertia effect and the material strain rate dependency. By observing the axial stress distribution and deformation behaviour in detail, and by calculating the strain rate near the vertex of a wrinkle when the peak load is observed, both effects on the peak load are clarified. Moreover, an approximate equation to evaluate the peak stress is proposed and in good agreement with the FEM results and other researcher's results under a relatively low impact velocity (V0<40m/s).