Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Load on and strength of tools in bulk metal forming

Datum: 03.07.1996


  • Prof. Dr.-Ing. habil. Ulf Engel


  • Prof. Dr.-Ing. Dr. h.c. M . Geiger
  • Prof. em. Dr.-Ing. Dr.h.c. K. Lange, Universität Stuttgart

The University of Erlangen-Nuremberg has conferred the qualification of university lecturer on Dr. Engel. As final step of the procedure to obtain this qualification, Dr. Engel has presented on July 3rd a public lecture on "Microforming - umformtechnische Herstellung von Kleinstteilen". anoterh step before was the publication of his postdoctoral thesis on "Beanspruchung und Beanspruchbarkeit von Werkzeugen der Massivumformung". About the subject of the book: The qualitiy of too, which can be characterized by its service life, its reliability and its precisisch, represents a decisive criterion for economical and safe processing in bulk metal forming. Thus it is an imperative demand fo an optimump process to make this criterion available already in the phase of laying out the process. In this monograph the stat of the art on such methods of assessment is compiled. Starting from this basis, a concept fo the prediction of tool life and tool reliability is derived, which can be applied quite efficiently in planning, laying out and optimizing the forming process. The kernel of this concept is a formulation well known from the general reliability theory in engineering: the systematic, deterministic-probabilistic analysis of load on and strenght of the tool. The deterministic component of the concept is given by the numerical process simulatin in combination with the modelling of the specific failure mechanisms on the basis of tribological methods and methods of damage mechanics as well as fracture mechanics. The stochastic phenomena can be quantified by statistical formulations. The combination of both the deterministic and probabilistic component, which can be realized by the interference analysis, yields an universal planning instrument - a kind of extentded process simulation -, which enables not only an estimate of tool life and tool reliability, but also an identification and an assessment of those primary parameters of influence, which most significantly affect the tool performance. Capabilities and future applications of this concept are shown by examples considering the optimization of forming processes.