FEM/BEM for metal chipping

Metal chipping processes are an important part of active research and of high scientific and industrial importance. Even in the simplest case of orthogonal cutting many questions are open, since e.g. several physical processes are involved in the chip development such as large plastic deformations of the workpiece, a material seperation at the tip of the worktool, friction of chip and workpiece at the surface of the cutting wedge as well as the development  of heat due to these processes which leads to a change of the material properties. Finally there is a  complex interaction between the worktool/workpiece system and the maschine which moves the worktool; this can lead to oscillations and chatter. The coupling between thermical and mechanical processes, e.g. at plastic heat develeopment, as well as the describtion of the material behaviour are decisive for the numerical simulation.
With the symmetric coupling of the viscoplastic boundary element method (BEM) and viscoplastic  finite element method (FEM) we use the advantages of both methods for the efficient simulation of metal chipping processes (incooperating the thermo-mechanical coupling and friction contact).  The FE/BE coupling is discretized with h- and p-versions. A posteriori error indicators can be used for adaptive error control.

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1. E.P. Stephan, S. Geyn, M. Maischak and M. Andres, A boundary element / finite element procedure for metal chipping, CMM 2007, Lodz-Spala, Poland

Principal investigator, research assistant

E. P. Stephan, M. Maischak, S. Geyn, M. Andres