Experimental analysis of a machining system with adaptive dynamic stiffness

• Autorzy: Frangoudis C. , Nicolescu C. M. , Rashid A.
• Języki publikacji: EN

Abstrakty

EN

A main consideration in the operation of machine tools is vibrations occurring during the cutting process. Whether they are forced vibrations or self-excited ones, they have pronounced effects on surface quality, tool life and material removal rate. This work is an experimental study of interactions between natural characteristics, control parameters and process parameters of a machining system designed with adaptive dynamic stiffness. In order to comprehend these interactions, the effect of changes in dynamic stiffness on the system's response is examined. The system under study consists of an end-milling tool, a steel workpiece and a work holding device with controllable stiffness. Natural dynamic characteristics of the system components are determined through modal impact testing. Then the behaviour of the whole machining system is examined under both high and low cutting speed conditions by analysing vibration levels using acceleration signals acquired through a tri-axial sensor mounted on the workpiece. Cutting is performed in both directions of the horizontal plane of a CNC milling machine. In both cases the results are presented for two extremes of stiffness and damping in the work holding device. The effect of control parameters on the system's natural characteristics could be identified together with a relation between these parameters and the system's response in high and low cutting speed conditions. The high-damping configuration reduces the vibration amplitudes significantly, while the increase of pre-stress has a different effect depending on the cutting conditions.

Słowa kluczowe

EN

vibrations; milling; damping; stiffness; adaptive structure

• Wydawca: Wydawnictwo Wrocławskiej Rady FSNT NOT
• Czasopismo: Journal of Machine Engineering
• Rocznik: 2013
• Tom: Vol. 13, No. 1
• Strony: 49--63
• Opis fizyczny: Bibliogr. 11 poz., tab., rys.

Twórcy

autor

Frangoudis C.

• The Royal Institute of Technology, Department of Production Engineering

autor

Nicolescu C. M.

• The Royal Institute of Technology, Department of Production Engineering

autor

Rashid A.

• The Royal Institute of Technology, Department of Production Engineering

Bibliografia

• [1] STEPHENSON D.A., AGAPIOU J.S., 2006, Metal Cutting, Theory and Practice, 2nd Edition, Taylor & Francis
• [2] TOBIAS S.A., 1965. Machine Tool Vibration, J. Wiley.
• [3] RIVIN E. I., 1999, Stiffness and Damping in Mechanical Design, Marcel Dekker, Inc.
• [4] ALTINTAS Y., BUDAK, E., 1995, Analytical prediction of stability lobes in milling, CIRP AnnalsManufacturing Technology, 44/1, 357-362.
• [5] FULLER C.R., ELLIOTT S.J., NELSON A., 1997, Active control of vibration, Academic Press
• [6] RASHID A., 2005, On passive and active control of machining system dynamics, analysis and implementation, Ph.D. Thesis.
• [7] LIU K., ROUCH K., 1991, Optimal passive vibration control of cutting process stability in milling, Journal of Materials Processing Technology, 28/1-2, 285-294.
• [8] MEHTA N., PANDEY P., CHAKRAVARTI G., 1983, An investigation of tool wear and the vibration spectrumin milling, Wear, 91/2, 219-234.
• [9] GHANI A., CHOUDHURY I., HUSNI., 2002, Study of tool life, surface roughness and vibration in machiningnodular cast iron with ceramic tool, Journal of Materials Processing Technology, 127/1, 17-22.
• [10] RAO M.D., 2003, Recent applications of viscoelastic damping for noise control in automobiles and commercialairplanes,” Journal of Sound and Vibration, 262/3, 457-474.
• [11] SHI X., POLYCARPOU A.A., 2005, Measurement and modeling of normal contact stiffness and contact damping at the mesoscale, Journal of Vibration and Acoustics, 127/1, 52-60.