ANALYSIS OF SHEAR BANDS IN DYNAMIC AXISYMMETRICAL COMPRESSION OF A THERMOVISCOPLASTIC CYLINDER

We study dynamic axisymmetric thermomechanical deformations of a viscoplastic cylinder with its boundaries assumed to be thermally insulated, its mantle traction free, and its top and bottom surfaces compressed at a prescribed rate. We consider two limiting cases of the frictional force between the loading device and the cylinder, i.e. either there is no sliding between the two surfaces, or there is smooth contact. It is found that the shear bands initiate much later when frictional force is neglected than when it is considered. A comparison of the presently computed results with those for the case when the body is assumed to be deformed in plane strain compression reveals that the initiation of shear bands is delayed significantly for the axisymmetric problem.