High-Rate Shear Deformation and Failure in Structural Alloys

Experiments were conducted to determine the dynamic shear behavior of a wide range of aluminum, titanium, and steel alloys. Principal experimental techniques were the torsional Kolsky bar and the Shear Compression Specimen (SCS) geometry. For the purpose of determining adiabatic shear susceptibility in this range of alloys, it was found that both techniques were unable to induce adiabatic shear in alloys resistant to that failure mode. The SCS geometry has demonstrated a capability for characterizing shear deformation behavior over a wide range of strain rates. For modeling and simulation of adiabatic shear phenomena, an improved adiabatic temperature evolution equation has been implemented. Finite element simulations of the torsional Kolsky and SCS geometries were conducted to evaluate the influence of pre-existing geometric inhomogeneities on adiabatic shear band initiation.