Object oriented design of a thermo-mechanical FEM code

An object oriented design is presented for a computer program that can perform thermo-mechanically coupled analyzes. The target of the design is a exible and robust computer program. It should be easy to adapt and extend, re-using existing code, without interfering with already established algorithms. The program uses publicly available toolkits that are currently emerging as C++ pack- ages. First of all the Standard C++ Library (formerly Standard Template Library) is used for packing items in container classes. Secondly the matrix and vector operations are derived from the Template Numerical Toolkit (TNT) and �nally (not essentially for the numerical part) a graphical user interface is made, based on the wxWindows package, that can generate a GUI for Motif and MS-Windows with the same code. Attention is given to the design of classes such as speci�c elements and material classes based on more general classes. A hierarchy of classes is constructed where general behavior is put high in the hierarchy and speci�c behavior low. The choice between inheritance and aggregation is made at several levels.