抄録
The inelastic constitutive equation is effective to the detail design of the components which are often imposed to inelastic deformation. Hart have been introduce the plastic state equation for the inelastic constitutive equation. This constitutive equation was matching well in the macroplastic deformation. But in the microplastic region, these equations are not representation. In this report, I introduce a technical modifications of Hart's constitutive equation for the microplastic region. This modification includes a application of the two yielding surface theory. The results are good representation for the experimental data in the nonlinear region of the stress-strain diagram.
