School of Engineering and Materials Science
Research Student Awards
PhD Thesis: Numerical Structure for Milling Proceses of Thin Wall Structures
Author: ADETORO, Oluwamayokun
Supervisor(s): Pihua Wen
In this thesis, an approach to predicting both the average and instantaneous cutting force coefficients required in force models, using a Finite Element Method (FEM) based on an Arbitrary Lagrangian-Eulerian formulation (ALE) is presented. Due to the inherent flexibility of both the cutter and the workpiece, the milling process is naturally accompanies by both dynamic and static vibrations. In order to investigate the dynamic vibrations, the dynamic parameters of both the cutter and workpiece are required. A novel numerical and experimental investigation has been carried out in this thesis for the prediction of thin walled structure’s damping parameters. A newly discovered approach to predicting the structural damping parameters is proposed and its applications in thin-wall machining is presented. An FEM and Fourier Transform (FT) approach is presented, to obtain the frequency response function (FRF) required for the prediction of chatter vibration free cutting conditions.
A more accurate stability model that considers the effects of higher harmonics from highly intermittent milling process, the nonlinearity of the cutting force coefficients and axial immersion angle along the axial depth of cut is developed. A numerical approach to obtaining a converged solution to the stability model is presented. A method that uses the FEM and the FT approach and the improved stability model, whilst considering the nonlinearities of the thin-wall dynamics in predicted stable region is also presented.