Effect of Strain Rate on the Propagation of a Plastic Strain Pulse Along a Lead Bar

Abstract

Tests have been carried out to determine how pulses of plastic deformation disperse during propagation along a lead bar. Step function loading was employed in order to avoid complications resulting from the presence of relief stresses. By using a double pressure step technique, it was shown that the dispersion cannot be due solely to the nonlinearity of a time-independent stress-strain relation. On the other hand even a very simple model of a metal exhibiting a strain-rate effect serves to predict qualitatively all of the main features of the experimental observations. It is therefore concluded that in the case of lead a strain-rate effect plays an important part in controlling the behavior of a plastic strain pulse.

Dislocations and Plastic Waves

“…10 as (15) where~' the density of the released dislocations, is somewhat undetermined n . 6 2 function of' the stress and strain. If however t" is larger than 10 per em , a strain larger than 0.…”

Impact of Dislocation Theory on Engineering

“…This deduction is consistent with the experimental facts deduced by (26) . (27) (28) Sternglass and Stewart, Alter and Curhs, and Riparbelli.…”

Effects of high temperatures on rocks

“…However, researchers have found that the dynamic stress-strain curve of certain materials showed that the elastic modulus also varies with strain rates (Alter and Curtis, 1956;Bell, 1956;Sternglass and Stuart, 1953). This led to a strain rate dependent theory for plastic wave propagation in which the elastic modulus, E, is dependent on stress σ, strain ϵ, and the strain rate (Kolsky and Douch, 1962;Lubliner, 1964).…”