Vibration Suppression Mechanism of Skin Part Mirror Milling With a Moving Jet Support

Abstract An innovative noncontact vibration-suppression method is proposed to realize stable and precision machining of large and delicate skin parts. The machining of large skin parts poses a challenge, demanding improved dynamic stiffness without costly fixtures or potentially surface-damaging supports. The novel approach enables stable milling of complex skin parts by employing synchronized moving jet support to improve dynamic stiffness. This method promises universal applicability for skin parts of varying shapes, including those with freeform surfaces. While investigating the fundamental mechanism of jet support on cutting system dynamics, we conducted a thorough analysis exploring the impact of added mass and damping. Our findings reveal an increase in the system's mass due to the addition of a water layer adhering to the part's surface, and the fluid's viscosity contributed to heightened damping. We integrated the jet model with the thin plate theory, establishing a dynamic model for the jet-supported system. By solving Lagrange function, we derived the frequency response function of the cutting point on the workpiece under the influence of moving jet support. The experiments in a dedicated setup demonstrate an astounding 80% increase in dynamic stiffness with the implementation of jet support. The prediction error in the theoretical frequency shift caused by the added mass is only 5.128%, and the prediction error in the receptance peak variation due to additional damping is a mere 0.672%. Through skin part machining experiments, we validate the effectiveness of our vibration-suppression method.