Study On Theory And Experiments For Damping Tools With High Slenderness Ratio

The deep hole machining is a difficulty that universally encounters nowadays. Longboring, for example, limited by the parameters of the hole to be bored, the boring bar usedwas generally slender and long, apparently this will lower the stiffness of the bar. Vibrationwill occur easily with bar of this kind, so that the surface finishing of the hole can not meetthe usage requirements, if the vibration is so fierce that the machining process has to bestopped. Therefore, the attenuation for tools’ vibration is a urgent problem need to be solved.Damping technology of particle damping is a passive vibration control technique.Because the technology has the advantages of simple structure, low cost, effect significantadvantages which have been applied in various fields. And the technology in high temperature,corrosion and other harsh environment can also use. In this paper, according to thecharacteristics of particle damping, the boring bar vibration, damping effect and the actualcutting test particle damping.Firstly the bar of damping tool was designed on the base of theoretical calculation, andits5order natural frequency was presented; Secondly the movement mechanism on themixture of common particles and small particles was analyzed, and the contact force andenergy consumption on particles with the same material property were studied, the energyconsumption of particles was simulated through LS-DYNA, the speed change before and afterimpact was given, the influence of density and material property on energy consumption wasconsidered, then a preliminary choose for particles was made through the simulation on theimpact consumption with ANSYS; Finally, hammer test and boring cutting experiment wascarried on, the influence of different materials, sizes and filling ratio on complete vibration and small vibration was studied. And through the experiment we can get that the amplitudewas reduced to1/6of that without particle, and experiments show that the hybrid dampingeffect of granule and powder of two kinds of materials is also very good.