Dynamic crushing of thin-walled spheres: An experimental study

Experimental studies on dynamic behavior of thin-walled spheres and sphere arrays in response to different impact velocity are presented. Ping pong balls are selected to study the collapse of thin-walled spheres. The tests were carried out by a modified Split Hopkinson Pressure Bar (SHPB) test system. The experimental results show that the deformation of thin-walled spherical shells depends on the impact velocity. The dynamic force in the range of small elastic deformation is larger than its quasi-static counterpart, but significantly below the latter after snap-through of the shell. The deformation and buckling mode are sensitive to the loading rate. It is noted that the strain rate effect of the materials and the inertia effect of the shell should be considered in the analysis of the shells response to dynamic loading. (C) 2008 Elsevier Ltd. All rights reserved