Object-oriented nonlinear finite element programming: a primer: Fid-Bau Portal

Object-oriented nonlinear finite element programming: a primer

Commend, S. / Zimmermann, T.

The article describes an introductory object oriented finite element program for static and dynamic nonlinear applications. This work can be considered an extension of the original FEM Object environment dealing with linear elasticity (Y. Dubois-Pelerin and Th. Zimmermann, 1993) and nonlinearity. Mainly the static aspects are discussed in the paper. A detailed discussion of the object oriented approach applied to finite element programming was given by Th. Zimmermann et al. (1992) and Y. Dubois-Pelerin et al. (1992) The article presents an introductory object oriented finite element package for nonlinear analysis. The goal is to make a starting package available to newcomers to the object oriented approach and to provide an answer to the large number of demands for such a program received in recent times. In the first part of the paper, a brief recall of the basics of finite element modeling applied to continuum mechanics is given. Von Mises plasticity including isotropic and kinematic hardening, which is used as model problem, is described. The first part also presents an overview of the main features of the object oriented approach. Next, classes and associated tasks forming the kernel of the code are described in detail. A hierarchy of classes is proposed and discussed; it provides an immediate overview of the program's capabilities. Finally, interactions between classes are explained and numerical examples illustrate the approach.