The purpose of this research is to study the physical phenomena controlling the dynamic constitutive and failure behavior of rate sensitive metals alloys. A combined axial/torsional split Hopkinson bar will be developed and used to investigate the thermomechanical constitutive and localization behavior of such alloys when they are subjected to multi-axial dynamic loading. Emphasis will be placed on examining the phenomenon of failure mode transition (dynamic cracking vs. dynamic shear banding) associated with asymmetric impact loading of pre-notched plate specimens. A variety of high speed optical and thermographic diagnostic techniques will be used simultaneously to record mechanical and temperature fields during deformation, localization and failure.
