The Portevin-Le Chatelier effect: A description based on time delay

A mathematical description of the Portevin-Le Chatelier (PLC) effect-is pre sented in the form of delay differential equations. Inclusion of a delay ti me in the dislocation evolution equations has been found to be helpful in e xplaining a number of experimentally observed results. The results of the s imulation reproduce some basic features of the PLC effect such as the strai n-rate window within which the effect occurs, increase in stress drop and p eriod of stress oscillation with change in strain rate, and the occurrence of chaotic stress oscillations under certain conditions.