Strain localization and its connection with the deformed state of the material

The detection of the passage of a shear band over an undeformed material poses a new question about the causal connection between the strain and the formation of shear bands. The collapse of a thick-walled tube is considered from the standpoint of the spall mechanism, according to which localized strain bands under pulsed loading are the result of interference of unloading waves; the negative stresses in the extension zone in this case do not exceed the strength of the material. It is found that radial cracks and their continuations in the form of shear bands appear at the unloading stage after the strained state of the material has already formed as a result of collapse. In other words, damageability is superimposed on the deformed material, and both these processes are independent and accompany each other.