Thin-Walled Part Machining Process Parameters Optimization based on Finite-Element Modeling of Workpiece Vibrations

摘要

Arising vibrations when milling thin-walled parts are the most essential factor that limits machining productivity and surface location accuracy. Such vibrations have large amplitude and often result in irreversible workpiece damage on finishing stage. Vibrations appear as a result of resonance of workpiece natural frequencies and cutting force spectrum harmonics from tooth-passing impacts. To eliminate resonance vibrations it is suggested to tune spindle speed in such a way, that workpiece natural frequencies differs from tooth-passing frequency harmonics. In practice changing of natural frequencies due to stock removal and changing of cutter position during machining process need to be considered. To estimate natural frequencies and mode shapes of workpiece mounted on NC machine worktable and its evolution during the process it is reasonable to apply widespread finite element modeling software. Using of FEM methods for vibration process modeling is considered. Also practical example of machining thin blade of compressor's aerodynamic model is considered.