Improving dynamic process stability in milling of thin-walled workpieces by optimization of spindle speed based on a linear parameter-varying model

In milling of thin-walled workpieces, like aero engine blades, the reduction of vibrations is of central importance to reach a more economical and reliable process as well as an improved workpiece surface quality. However, the dynamic behavior of the workpiece continuously varies due to changes in workpiece stiffness and mass, caused by the moving position of the excitation force as well as the material removal. In this paper, the simulation of the changing workpiece dynamics for a simplified blade geometry using FE-modal analysis is demonstrated. All extracted workpiece dynamic states are combined in a reduced LPV-model (Linear Parameter-Varying model). The LPV-model is able to describe the varying process dynamic behavior and makes the selection of advantageous spindle speeds possible.