In this paper, through theoretical discussion and by obtaining numerical results, the values of critical impact velocity of various materials, such as metals of various crystal structures and non-metals, have been estimated at different temperatures and strain rates, when the specimens or bars of these materials are subjected to a tension or a torsion impact with sufficiently high velocities. The theoretical approach is made by the method of characteristic curve, provided that the conditions are the same as those in the case of Karman-Duwez solution where simple waves are propagated. Then, the values of the critical impact velocities for various materials at different temperatures and strain rates are evaluated. In addition, some experimental investigations for processing thin plates are made by high speed perforation. Some of the most significant experimental results are presented.
