An improved prediction of stability lobes using nonlinear thin wall dynamics

With manufactured sections getting much thinner due to weight requirements, there is the vital need for more accurate prediction of stable cutting conditions in machining. The tools used in machining vary in shapes and design hence a more robust model is required to include these varieties. This paper first presents improvements to the well known stability model, by considering the nonlinearity of the cutting force coefficients, and axial immersion angle and their dependency on the axial depth of cut. Secondly, a finite element (FE) and Fourier transform approach to including the nonlinearity of the workpiece dynamics in thin wall machining when predicting stable region is presented. The model and approach are validated extensively using experimental results and a very good agreement has been achieved.