Strain localization phenomena associated with static and dynamic strain ageing in notched specimens:: experiments and finite element simulations

The aim of the present work is to use an available constitutive model for the description of the Portevin-Le Chatelier effect to simulate the deformation of notched specimens in tension (smooth and sharp U-notched specimens). This model can be used to account for dynamic strain ageing as suggested by Estrin et al. [Acta Mater. 49 (2000) 1087] but also static strain ageing as suggested by Kubin et al. [Acta Metall. Mater. 40 (1992) 1037]. The experimental material studied is an Al-Cu alloy, displaying dynamic strain ageing at room temperature. Regarding Luders band propagation, the experimental material studied is a mild steel. This work shows that the PLC serrations disappear progressively on the macroscopic curve when the notch radius decreases. However, strain localization still takes place in the deformed notched zone, and can escape from the notched zone. Regarding the Luders behavior, the computed spreading of deformation bands is in agreement with experimental observations. (C) 2004 Elsevier B.V. All rights reserved.