Constitutive equations for modeling non-Schmid effects in single crystal bcc-Fe at low and ambient temperatures

• Published in: International journal of plasticity Vol. 59; pp. 1 - 14
• Main Authors: Patra, Anirban, Zhu, Ting, McDowell, David L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-08-2014
• Subjects: Ambient temperature; Asymmetry; Bcc; Constitutive equations; Constitutive relationships; Crystal plasticity; Iron; Mathematical models; Non-Schmid; Plasticity; Single crystals; Temperature dependence; Yield stress; Temperature dependence; Crystal plasticity; Iron; Bcc; Non-Schmid
• ISSN: 0749-6419; 1879-2154
• DOI: 10.1016/j.ijplas.2014.03.016

•A crystal plasticity framework is developed for modeling non-Schmid effects in bcc crystals.•Decay of the non-Schmid stresses with increase in temperature is modeled.•Constitutive equations are developed for decay of the non-Schmid stresses with inelastic deformation.•The stress–strain response and hardening behavior of bcc-Fe at 298K is modeled and fit to experiments.•Orientation- and temperature-dependent yield stress and tension–compression asymmetry of bcc-Fe is modeled.
Constitutive equations are developed for single crystal bcc-Fe at low and ambient temperatures based on the assumption that non-Schmid effects are primarily influential on orientation dependence and tension–compression asymmetry of the initial yield stress. Temperature dependence of the non-Schmid parameters is extracted from a fit to available experimental data. Constitutive models are also developed for the decay of the influence of non-Schmid stresses with inelastic deformation. These equations are used in a dislocation density-based crystal plasticity framework to model the mechanical behavior of bcc-Fe. The stress–strain response is modeled and fit to the experimental data at 298K. Orientation-dependent yield stress and tension–compression asymmetry simulations are compared to available experiments.