抄録
The most useful non-local constitutive equation for the analysis of localized plastic deformation would be the gradient plastic constitutive equation proposed by Aifantis. However, it involves the gradient of internal variable and thus the treatment of it at the boundary is difficult. Then, it has been modified mathematically by Vardoulakis transforming it to the relationship between the stress rate and the strain rate with its gradient, and thus the analysis of the boundary value problem has been simplified drastically. In this article the generalized formulation of the gradient plasticity is first given by incorporating the general gradient terms of internal variables. Then, it is extended to the unconventional plasticity by incorporating the subloading surface model. Moreover, it is extended so as to be applicable to the description of plastic instability phenomena by incorporating the tangential plastic strain rate. Besides, the equation for the analysis of shear band thickness in the post-localized deformation is given based on the present constitutive model.
