Time Integration of the Dual Problem of Elastoplasticity by Runge-Kutta Methods

Implicit Runge-Kutta methods for the dual problem of elastoplasticity are analyzed and classified. The choice of Runge-Kutta time integration is inspired by the problem structure, which consists of a coupled system of balance equations and unilaterally constrained evolution equations and which can be viewed as an infinite-dimensional differential-algebraic equation. Focussing on the time axis and leaving the space variables continuous, a grid-independent existence and uniqueness result is given for the class of coercive Runge-Kutta methods. Moreover, contractivity preservation and convergence are shown for methods that are also algebraically stable.