A viscoplastic constitutive model for nickel-base superalloy. II: Modeling under anisothermal conditions
Being not sufficient to evaluate the stress relaxation under cyclic deformation at high temperature because generally the temperature varies, the inelastic behavior is investigated also under anisothermal conditions. As in previous study [the authors, ibid. 18, No. 8, 1083--1109 (2002; Zbl 1045.74015)], the authors present experimental tests for monotonic tension and subsequent strain hardening, creep and cyclic deformation. Diagrams stress-temperature or -strain, stress relaxation-hold tension, creep-strain for different strain-rates, stress-number of cycles and hysteretic loops furnish experimental data for subsequent simulations. The constitutive equations are the same as previously, but the material constants depend upon the temperature empirically expressed for different thermic intervals. The plotted diagrams with effective and simulated curves for back stress-temperature and stress-number of cycles for different strain ranges, and an additional correction tensor of back stress lead to relevant conclusions. The inelastic behavior is almost independent of the temperature and loading rate below \(700^\circ\), anomalous behavior of in-phase and out-of-phase types does exists, the stress continuing to evolve cycle-by-cycle in the direction by lower temperature, and the additional correction of back-stress becomes active under higher temperatures. The proposed viscoelastic models is consequently successfull.
scientific article; zbMATH DE number 1797354