PLANE-STRAIN FLOW LOCALIZATION IN TENSION AND COMPRESSION OF THERMO-ELASTO-VISCOPLASTIC BLOCKS UNDER HIGH-RATES OF DEFORMATION

A numerical simulation of dynamic flow localization in tension and com pression of plane-strain blocks under a wide range of deformation rate s and different boundary conditions has been performed. The material i s characterized by incorporating the strain-rate and temperature sensi tivities through J2-type generalization of the expression relating uni axial stress, strain, strain rate and temperature. Positive and negati ve strain rate history dependences of the flow stress under abruptly i ncreasing strain rate are also considered for specific materials. By m eans of plane-strain explicit finite element analysis, we explored the effects of deformation rate, strain rate and temperature sensitivitie s of materials, strain rate history dependence of the flow stress and size of the specimen on the flow localization.