Extension of a finite element model to 2D for the prediction of adiabatic shear bands

Abstract

Failure of metals under impact loading is known to occur through the formation of adiabatic shear bands (ASBs). ASBs appear in materials as evidence of damage, and are known to be sites for material failure. General purpose plasticity models fail to predict the phenomenon of ASB formation. The present research validates and extends a model developed at the University of Manitoba by Feng and Bassim to predict damage due to ASBs. Parameters for the Feng and Bassim model are determined experimentally using a direct impact pressure bar to impact specimens at temperatures of 20-500oC and strain rates of 500-3000/s. A direct impact experiment is simulated in ANSYS using the model and fitted parameters. The results of the simulation show localized temperature rise and predict failure at the same locations as those observed experimentally. Nominal strain to failure is approximately 40-50% for a specimen impacted at 38 kg-m/s.