UTILITY OF THE RING EXPANSION TEST IN THE ANALYSIS OF DIFFERENT LAWS OF ELASTOPLASTIC BEHAVIOR AT HIGH STRAIN RATES - APPLICATION TO COPPERAND MARS-190 STEEL

The expanding ring test represents a new experimental technique allowi ng the study of high strain rate material behavior. This test allows t o validate various constitutive relations for strain rate up to 10(4) s(-1), or, in addition of dynamic test like Split Hopkinson Pressure B ars bars, to calculate associated coefficients to these models for the se strain rates levels. In this work, we evaluate three elastoplastic models on two materials : copper and armor steel.