土井 恵介 (Keisuke DOI)
The Jaumann rate of the Cauchy stress is often used to describe the incremental constitutive relations in finite deformation. However, it leads to oscillatory response in simple shear and to relatively high nonlinear resistance in tension. We here introduced several objective stress rates in order to compare their characteristics and applicability. Especially an emphasis is put on eligibility of the consistency condition of the yield condition. Numerical results show that the difference on the load-stretch curves is small between chosen stress rates when the yield condition is reasonably satisfied. Therefore, the Truesdell stress rate, for example, can be used in wide range of strains without any strange predictions of the material responses. Finally, the predicted directions of the localized deformation are compared as an application.
Key Words : Stress Rate, Localization, Finite Deformation