A flexible force model for end milling of low-rigidity parts

There is a high complexity associated with modelling of cutting forces in machining of thin-wall parts due to the variable part/tool deflection and changing tool immersion angle. The paper reports on a new analytical flexible force model suitable for static machining error compensation of low rigidity components. The model is based on an extended perfect plastic layer model integrated with a finite element model for prediction of part deflection. At each computational step, the flexible force is calculated by taking into account the changes of the immersion angles of the engaged teeth. The material removal process at any infinitesimal segment of the milling cutter teeth is considered as oblique cutting, for which the cutting force is calculated using an orthogonal–oblique transformation. Both the force model and the experimental verifications, use a statistical analysis of the average force. To verify the model the theoretically predicted force is compared with the measured force using a set of cutting trials.