Modeling the Surface Structure Created by End Milling in the Presence of Tool Vibrations

Biermann, D.^{1, a}; Surmann, T.^{1, b}

1)

Institut für Spanende Fertigung, Technische Universität Dortmund, Baroper Str. 301, 44227 Dortmund

a) biermann@isf.de; b) surmann@isf.de

Kurzfassung

This paper presents a geometric model for the generation of the surface structure, which is produced by slab milling with vibrating milling tools. Since tool vibrations are always present, even in chatter-free milling, they must be taken into account as well as run-out, when modeling surface structures. Tool vibration trajectories can be calculated by an existing time domain simulation of the dynamic milling process, but they do not intuitively show their effect on the surface quality. Using the tool vibration trajectory together with a geometric representation of the cutting edges, a sweep surface of the cutting edges can be generated by superposition of the ideal, trochoidal cutting edge movement with the tool vibration. In addition to this, the tool bending, which is responsible for an oscillating loss of contact of the cutting edges from the surface, is taken into account. Then, the sweep surface can be projected into a volume model of the machined surface in order to produce a topographic surface model. It is shown that each vibration type (chatter-free, chatter, and flip-chatter) generates a specific kind of surface topography and roughness.

Schlüsselwörter

Milling Simulation, Surface Structure, Milling Dynamics

Veröffentlichung

In: Proceedings of the 11th CIRP International Conference on Modeling of Machining Operation, 16.9.-18.9. 2008, Gaithersburg, MD USA, Haigel, J. C. (Hrsg.), S. 171-177