Consideration of Microstructural Changes in the Study of Adiabatic Shear Bands.

Abstract : We have analyzed the effect of microstructural changes on the initiation and growth of shear bands. These have been studied by developing an adaptive mesh refinement technique to decipher adiabatic shear bands in two-dimensional problems, formulating a three-dimensional finite-deformation theory for dipolar thermoviscoplastic materials and using it to examine the initiation and growth of shear bands in plane strain thermomechanical deformations of dipolar materials, employing an internal variable theory of Brown, Kim and Anand to study the shear band problem, investigating the possibility of phase transformations during the development of adiabatic shear bands in a steel specimen, ascertaining the speed of propagation of a shear band in a steel tube, assessing the effect of frictional forces between the loading device and the cylinder ends, and, analyzing the development of a shear band in a FCC single crystal. Principal results obtained during these investigations are summarized in the report. (AN)