THEORY OF INFINITESIMAL DISLOCATIONS DISTRIBUTED ON A PLANE APPLIED TO DISCONTINUOUS YIELD PHENOMENA

Publisher Website
Google Scholar
Abstract
An analysis is made of the behavior of groups of dislocations in a slip band, when the frictional stress that hinders dislocation motion undergoes a static or a dynamic drop. A static stress drop is the lowering of a frictional stress that decreases with increasing displacement across the slipped zone; a dynamic stress drop is associated with a frictional stress that decreases with increasing velocity of displacement. It is shown that the presence of a static stress drop can lead to the upper and lower yield point phenomena, even if the stress drop is very gradual. The dynamic case leads to the Portevin–Le Chatelier effect (serrated stress–strain curves). According to this analysis, the Portevin–Le Chatelier effect has its origin in the inherent instability of a boundary separating dislocations that are acted upon by a high frictional stress from those acted upon by a low frictional stress.

This publication has 5 references indexed in Scilit: