The IBF has for some years made use of finite element programmes to solve metal‐forming problems. In the course of this investigation, it has become evident that a problem‐oriented adaptation of FEM simulation to the problem in hand is beneficial in terms of computation effort. The computation time for the process parameters is optimised in a multi‐level simulation. At level 1 (global analysis) integral parameters such as the required force and required work are computed using a coarse FEM mesh. At level 2 (local analysis) an optimised number of elements is used to determine continuum mechanics parameters like stress, strain and temperature. Microscopic phenomena are simulated at level 3 (microscopic analysis), using special micro‐material elements and thermodynamic models.

It is becoming increasingly apparent that the correct description of the boundary conditions of a forming process is of decisive importance for the computational accuracy of FEM results. The effects of various influencing variables on the computational accuracy of an FEM programme have been analysed at the IBF. The various influencing variables are discussed in relation to precise experimental findings and the results of analytical or other FEM solutions, and it is shown that uncritical use of FEM programmes can often lead to considerable inaccuracies. In addition, the limits of current continuum‐mechanics simulation are indicated and possible ways of extending those limits discussed.

Der Stofffluß bei Umformprozessen hängt wesentlich von den Kontaktbedingungen Werkstück/Werkzeug ab. Soll der Stofffluß auf theoretischem Wege beschrieben werden, so ist es notwendig, daß eine mathematische Beziehung existiert, die die Vorgänge in der Kontaktfläche richtig abbildet. Ziel dieser Arbeit ist es, mit Hilfe bekannter Reibungstheorien die für theoretische Berechnungen von Umformprozessen meistens benutzten Reibansätze zu bewerten und Möglichkeiten aufzuzeigen, durch Koppelung von Theorie und Experiment zu objektiveren Reibansätzen zu gelangen.