Dynamic Necking of Rods at High Strain Rates

Dynamic Necking of Rods at High Strain Rates

The dynamic necking instability of a rod of a non-linear viscoplastic material as formed in shaped charges is investigated. A two-dimensional linear Lagrangian perturbation method leads to a single fourth order partial differential equation with time-dependent coefficients. The growth of disturbancies depends of the interplay between the stabilizing inertial and viscous effects, and the destabi...

PREDICTION OF HOT DEFORMATION BEHAVIOUR OF A PH STAINLESS STEEL AT HIGH STRAIN RATES

In this study the hot deformation behaviour of a precipitation hardened (PH) stainless steel at high strain rates has been predicted through hot compression testing. Stress-strain curves were obtained for a range of strain rates from 10-3 to 10+1 S-1 and temperatures from 850 to 1150°C. Results obtained by microstructure and stress-strain curves show that at low temperatures and high strain rat...

Experimental methods at high rates of strain

The subject area covered by this review is a large and important one and to do it full justice would require a larger format than is available here. However, an attempt is made to outline the history of some of the more important developments and to include most major techniques. Taylor impact, Hopkinson bar testing in its various forms and 1-D plate impact are all considered in some detail. Hi...

Large Strain Range Dynamic Testing at High and Medium Strain Rates, Using a Common Scale SHPB

Glass dynamics at high strain rates.

We present a shear-transformation-zone (STZ) theoretical analysis of molecular-dynamics simulations of a rapidly sheared metallic glass. These simulations are especially revealing because, although they are limited to high strain rates, they span temperatures ranging from well below to well above the glass transition. With one important discrepancy, the simplified STZ theory used here reproduce...