A constitutive model for fcc crystals with application to polycrystalline OFHC copper

Based on the results of a series of experiments on commercially pure OFHC c opper tan fee polycrystal), a physically based, rate- and temperature-depen dent constitutive model is proposed for fee single crystals. Using this con stitutive model and the Taylor averaging method, numerical calculations are performed to simulate the experimental results for polycrystalline OFHC co pper. The model calculation is based on a new efficient algorithm which has been successfully used to simulate the flow stress of polycrystalline tant alum over broad ranges of temperature, strain rate, and strain (Nemat-Nasse r, S., Okinaka, T., Ni, L., 1998. J. Mech. Phys. Solids 46, 1009). The mode l effectively simulates a large body of experimental data, over a broad ran ge of strain rates (0.001-8000 s(-1)), and temperatures (77-1096 K), with s trains close to 100%. Few adjustable constitutive parameters of the model a re fixed at the outset for a given material. All other involved constitutiv e parameters are estimated based on the crystal structure and the physics o f the plastic flow. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.