Design and implementation of two-degree-of-freedom tuned mass damper in milling vibration mitigation

The tuned mass damper (TMD) has been applied to the machining vibration control widely, and it is categorized into several groups depending on the available degrees of freedom (DOF). Previous works have been mostly focused on the application of single-DOF TMD, but it is revealed that the damping performance could be further promoted by multiple-DOFs TMD. A two-DOF TMD for the milling vibration mitigation is investigated. The TMD possessing translation and rotation motion is designed with tunable stiffness and damping, and the design parameters are optimized numerically based on the H∞ criterion. The TMD is implemented on a workpiece fixture with single dominant mode, and the experimentally tuned frequency response function (FRF) has 80.8 percent reduction on the amplitude of the flexible mode. Spindle speeds corresponding to the resonance and chatter vibrations are selected for the machining tests. The measured vibrations and surface quality validate the improvement of the machining stability by the TMD, and the critical depth of cut is increased at least two folds.