This research will evaluate prestrain effects on constitutive equations for plastic flow behavior of materials. This research investigation determines the effects of dynamic compressive pre-strain on the subsequent plastic flow behavior of metals. Experimental studies will be carried out in two fcc metals (6061-T6 aluminum, a fairly rate insensitive materials, and annealed OFHC copper, a rate sensitive materials) to understand the micro-structural changes that are associated with dynamic compressive pre-strain by means of plate impact and split Hopkinson bar (SHB) experiments. The results will be coupled to a state variable based constitutive model for describing the observed plastic flow behaviors in these two materials.
