A functional type a posteriori error analysis for the Ramberg-Osgood model

Abstract

We discuss the weak form of the Ramberg-Osgood equations (also known as the Norton-Hoff model) for nonlinear elastic materials and prove functional type a posteriori error estimates for the difference of the exact stress tensor and any tensor from the admissible function space. These equations are of great importance since they can be used as an approximation for elastic-perfectly plastic Hencky materials.