NUMERICAL MODELING OF THE PORTEVIN-LE CHATELIER EFFECT

A numerical model has been developed to describe the inhomogeneous def ormation associated with the Portevin-Le Chatelier effect. The model i s based on the transient behaviour of dynamic strain ageing resulting from the time dependence of the solute concentration at arrested dislo cations. Spatial effects are included through a Bridgman-type factor w hich takes into account stress triaxiality effects at geometrical inho mogeneities. Numerically simulated stress-strain curves are shown to b e in excellent agreement with experiment, with all of the important fe atures of the Portevin-Le Chatelier effect being exhibited by the mode l.