DETERMINATION OF CONSTANTS AND COMPARISON OF RESULTS FOR VARIOUS CONSTITUTIVE MODELS

The ability to compare different constitutive models has been difficult in the past because the constants associated with these models are developed using different methods and test data. This work presents an explicit, consistent procedure for which constants can be determined for different constitutive models using the same test data base. This allows for a direct comparison of the models to be made independent of the material constants. Using this procedure, constants are determined for four material models : Johnson-Cook, Modified Johnson-Cook, Zerilli-Armstrong, and a Combined Model (from Johnson-Cook and Zerilli-Armstrong) using two materials : OFHC Copper and Armco Iron. Comparisons are made between the different models by simulating Cylinder Impact experiments using the EPIC code.