ANGLE DOMAIN ANALYTICAL MODEL FOR END MILLING FORCES

This paper presents the development of an explicit expression of cutti ng force waveforms in end milling with helical multi-flute cutters. Fr om the relationship of elemental cutting forces and chip load, the net cutting forces are analytically formulated based on the integration o f elemental cutting forces in the feed, cross feed, and axial directio ns. This formulation leads to a solution of force waveforms as algebra ic functions of tool geometry, machining parameters, cutting configura tion, and workpiece material properties. The closed-form nature of the resulting model facilitates force estimation and process optimization without resorting to numerical iterations. The theoretical error of p rediction due to the truncation of higher frequency terms is analyzed It provides a guideline for choosing the model size for given error to lerance. It also offers an understanding of upper bound of prediction error for a known number of approximating terms used in the model. In the paper end milling experimental results were examined over a range of conditions to verify the analytical model in the context of wavefor m, power spectrum and model size effect.