Modified Hill yield criterion for better prediction of quasi static and dynamic behavior

Abstract
In order to simulate dynamic response of structures, the knowledge of the mechanical behavior of materials submitted to complex loading has to be improved. In this paper, we determine a specific criterion for a rolled sheet of tantalum, as a function of strain rate. We introduce a technique of determination of parameters based on uniaxial tests. Appropriate validation experiences confirm the applicability of the criterion. Some parameters appear to be independent of strain rate and temperature while the parameter which describes the difference between tension and compression seems to follow a thermally activated law. Comparison with classical criteria shows the importance of a good yield criterion for the simulation of elastoviscoplastic behavior.