The study of plastic strain localization in cylindrical skewed specimens under dynamic loads

Abstract

The study of plastic strain localization in skewed specimens made of AMg6 alloy was carried out under conditions of dynamic tests on a split Hopkinson pressure bar. Temperature fields were studied “in-situ” using a high-speed infrared camera. The temperatures measured in the localization zone do not confirm the traditional views of the strain localization mechanism as being conditioned by thermoplastic instability of the examined materials under realized loading modes. Comparison between the experimentally obtained temperature fields and the results of numerical simulation made with account for the kinetics of microdefect accumulation in the material, demonstrates that they agree to an accuracy of ~20%. Experimental studies and their numerical simulation that takes into account the evolution of the defect structure of the material, confirm the idea that the mechanism of plastic strain localization is associated with the processes arising in the system of microdefects in the examined material under loading modes implemented during dynamic tests.