Design and optimisation of a turning cutter embedded with impact damper

The cutter with large length-diameter ratio has wide applications in machining structural parts with deep cavity and deep hole features. However, chatter occurs as its declined dynamic stiffness. The impact damper has been utilised to suppress machining vibration due to its simplicity and effectivity. A turning cutter with large length-diameter ratio is designed based on embedded impact damper. The dynamic model is built based on mode superposition method. The influence of cutting force and damping parameters on velocity response status (linear and nonlinear) is analysed. Design parameters of the impact damper are optimised numerically for achieving linear response. Finally, modal tests and machining tests are conducted. The experimental results show that the surface roughness of workpiece (aluminium alloy 7075) is decreased from Ra 1.95 μm to Ra 1.28 μm when the spindle speed n = 500 r/min, feed rate f = 0.05 mm/r, and cutting depth a_p = 0.40 mm.