Mechanical characterization and constitutive modeling of aluminum AA1050 subjected to high strain-rates

Viscoplastic constitutive model considering strain rate sensitivity under multiaxial thermomechanical fatigue loading

“…Compared with Barrett et al's model 42 considering strain rate sensitivity, in which the relationship between the inelastic strain increment and the time increment is still linear, the model proposed in this paper can express the different influences of strain rate sensitivity on the cyclic stress response, as show in Figure 1, which is beneficial to improve the accuracy of life prediction. Compared with other constitutive models [43][44][45][46] considering strain rate sensitivity that are verified under static loading, the viscoplastic function modified in this paper belongs to the Chaboche model widely used under high-temperature cyclic loading, which is more beneficial to the application of the proposed model under MTMF loading.…”

“…Moreover, after systematically studying the thermoviscoplastic behavior of DP800 steel in a wide range of strain rates, Jia et al 43 found that DP800 steel exhibited nonlinear strain rate sensitivity; then, a semiphysical constitutive model was developed, in which the viscous drag effect is considered to indirectly capture the strain rate sensitivity. dos Santos et al 44 proposed a phenomenological elastic‐viscoplastic constitutive model, which focuses on describing some mechanical behaviors of the material under high strain rate loading, including strain hardening, strain rate hardening, and instantaneous flow stress rate sensitivity. Li et al 45 experimentally found that AA2219 aluminum alloy exhibited negative strain rate sensitivity below the critical temperature of 143°C and positive strain rate sensitivity above the critical temperature and then modified the existing strain rate sensitivity equation considering the negative to positive strain rate sensitivity.…”