The major objectives of this work are to predict the yield locus, normal anisotropic ratio (R-value), stress response and Forming Limit Diagram (FLD) of an aluminum alloy sheet at different strain-rates using an appropriate anisotropic yield criterion and a constitutive model. In order to achieve these objectives, a comprehensive study of quasi-static and dynamic responses of two FCC metals is performed to understand the material behaviors at large deformations and over wide ranges of strain-rates and temperatures. The two FCC metals include Oxygen Free High Conductivity (OFHC) copper and an aluminum alloy (AA5 182), which have applications in the defense and automotive industries, respectively. In case of AA5182, the material includes the base alloy and welded materials called “Tailor Welded Blanks” (TWBs).

Quasi-static tensile strain-rate jump experiments at room temperature are performed on aluminum alloy (AA5 182) sheet. Tensile split-Hopkinson pressure bar (SHPB) experimental setup is developed to perform tensile experiments at high strain rates and at different temperatures. Further, to determine the anisotropy in the material, several experiments are performed in different directions of the sheet metal.

The comprehensive study on OFHC copper includes results from quasi-static compression experiments performed at different strain-rates and temperatures. Dynamic compression experiments performed using the conventional SHPB technique, are also presented. The material responses under quasi-static and dynamic torsion loading conditions, using the MTS and torsional Kolsky bar respectively, are also presented. The compressive responses of the material under non-proportional paths are also studied at different strain rates. Constitutive modeling of these comprehensive responses is performed using a modified phenomenolo&oaøodel earlier developed by Khan et al. (1999 & 2004). This constitutive model captures-tho experhiental response reasonably well given the few material constants involved and the ease with which they”n be obtained. To remove any doubts of bias, this model is also used to correlate and predict the expetimental observations on the same material by McDowell et al. (1999), and Nemat-Nasser et al. (1998). The correlations andpredictions are again in good agreement with the experimental results. In conclusion, this model shows excellent capability to correlate and predict the experimental response of FCC metals and can be usedin predicting the FLD for the aluminum alloy.