Modern industry expectations in terms of milling operations often demand the milling of the flexible details by using slender ball-end tools. This is a difficult task because of possible vibration occurrence. Due to existence of certain conditions (small depths of cutting, regeneration phenomena), cutting process may become unstable and self-excited chatter vibration may appear. Frequency of the chatter vibration is close to dominant natural frequency of the workpiece or the tool. One of the methods of chatter vibration avoidance is matching the spindle speed to the optimum phase shift between subsequent cutting edges passes (i.e. the Liao-Young condition). However, the set of optimum spindle speeds from the point of view of vibration reduction may be not optimum one from other points of view. For example milling efficiency or machine tool capabilities cannot be assured. This article presents the idea of a workpiece holder with adjustable stiffness and discusses a new variant of its realization. In the holder, milling process is performed at constant spindle speed and feed speed. In order to avoid vibration the holder stiffness is modified. Stiffness changes modify natural frequencies of the workpiece and thus it is possible to modify dynamic properties of the workpiece in such a way that arbitrary chosen, constant spindle speed will be optimum, due to the Liao-Young condition performance. Calculation of the optimum stiffness is performed before milling, based on the workpieces modal identification results and the finite element model simulations.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Brecher C. Manoharan D. Ladra U. Köpken H.-G.: Chatter suppression with an active workpiece holder. Production Engineering Research and Development Vol. 4 (2010) pp.239-245.
2. Deja M. Siemiątkowski M. S.: Feature-based generation of machining process plans for optimised parts manufacture August 2013 Vol. 24 Issue 4 pp. 831-846.
3. Dohner J. L. Lauffer J. P. Hinnerichs T. D. Shankar N. Regelbrugge M. Kwan C.-M Xu R. Winterbauer B. Bridgerf K. : Mitigation of chatter instabilities in milling by active structural control. Journal of Sound and Vibration Vol. 269(2004) pp. 197-211.
4. Ganguli A. Deraemaekar A. Horodinca M. Preumont A.: Active damping of chatter in machine tools - demonstration with a „Hardware in the Loop” Simulator. Proceedings of the Institution of Mechanical Engineers Part I: Journal of System Control Engineering Vol. 219 (2005) pp. 359-369.
5. Hoffmann M. Powałka B. Berczyński S. Pajor M.: Identification of cutting forces in frequency domain in milling. Advances in Manufacturing Science and Technology Vol. 34 (1) (2010) pp. 5-20.
6. Iwicki P. Tejchman A. Chrościelewski J. : Dynamic FE simulations of buckling process in thin-walled cylindrical metal silos. Thin-Walled Structures (2014) pp. 344-359.
7. Kaliński K. J.: Vibration surveillance of mechanical systems which are idealised discretely (in Polish). Gdańsk University of Technology Publishers Gdańsk 2001.
8. Kaliński K. J. A surveillance of dynamic processes in mechanical systems (in Polish). Gdańsk University of Technology Publishers Gdańsk 2012.
9. Kaliński K. J. Chodnicki M. Mazur M. Galewski M. A.: Vibration surveillance system with variable stiffness holder for flexible details milling.[in:] Applied Non-Linear Dynamical Systems Springer Proceedings in Mathematics and Statistics J. Awrejcewicz Vol. 93(2014b) pp. 175-184.
10. Kaliński K. J. Chodnicki M. Galewski M. A. Mazur M. : Vibration Surveillance for Efficient Milling of Flexible Details in Adjustable Stiffness Holder.Vibroengineering Procedia Vol. 3 (2014c) pp. 215-218.
11. Kaliński K. J. Galewski M. A. : Chatter vibration surveillance by the optimal-linear spindle speed control. Mechanical Systems and Signal Processing Vol. 25 (2011) pp. 383-399.
12. Kaliński K. J. Galewski M. A.: Vibration surveillance supported by Hardware-In-the-Loop Simulation in milling flexible workpieces. Mechatronics Vol. 24(2014) pp. 1071-1082.
13. Kaliński K. J. Galewski M. A. : Optimal Spindle Speed Determination for Vibration Reduction During Ball- End Milling of Flexible Details. International Journal of Machine Tools and Manufacture Vol. 92 (2015) pp. 19-30.
14. Kaliński K. J. Galewski M. A. Mazur M.: High Speed Milling vibration surveillance with optimal spindle speed based on optimal speeds map. Key Engineering Materials Vol. 597(2014a) pp.125-130.
15. Kaliński K. J. Mazur M. Galewski M. A. : High speed milling vibration surveillance with the use of the map of optimal spindle speeds. [in:] Proceedings of the 8th International Conference on High Speed Machining Metz France (2010) pp. 300-305.
16. Kaliński K. J. Mazur M. Galewski M. A.: The Optimal Spindle Speed Map for Reduction of Chatter Vibration During Milling of Bow Thruster Blade. Solid State Phenomena Vol. 198 (2013) pp. 686-691.
17. Kim M.H. Won D. Ziegert J. : Numerical Analysis and Parameter Study of a Mechanical Damper for Use in Long Slender Endmills. International Journal of Machine Tools and Manufacture Vol. 46 (2006) pp. 500-507.
18. Liao Y.S. Young Y.C.: A new on-line spindle speed regulation strategy for chatter control. International Journal of Machine Tools and Manufacture Vol. 36 (1996) pp. 651-660.
19. Łuczak M. Manzato S. Peeters B. Branner K. Berring P. Kahsin M. : Updating Finite Element Model of a Wind Turbine Blade Section Using Experimental Modal Analysis Results Shock and Vibration Vol. 2014 issue 1 pp. 71-82.
20. Moradi H. Vossoughi G. Movahhedy M.R. Salarieh H.: Suppression of nonlinear regenerative chatter in milling process via robust optimal control. Journal of Process Control Vol. 23 (2013) pp. 631-648.
21. Nouari M. List G. Girot F. : Wear mechanisms in dry machining of aluminium alloys. International Journal of Mechanical Production Systems Engineering Vol. 4 (2003) pp. 22-29
22. Pajor M. Hoffmann M. Marchelek K. : Identification of cutting process model parameters for multi-edge rotating tools (in Polish) Modelowanie Inżynierskie Vol. 10 (2011) pp. 307-314.
23. Parus A. Pajor M. Hoffmann M. : Suppression of Self- Excited Vibration in Cutting Process Using Piezoelectric and Electromagnetic Actuators. Advances in Manufacturing Science and Technology Vol. 33 (2009) pp. 35-50.
24. Powałka B. Pajor M. Berczyński S. : Identification of nonlinear cutting process model in turning. Advances in Manufacturing Science and Technology Vol. 33 (3) (2009) pp. 17-25.
25. Quintana G. Ciurana J. : Chatter in machining processes: a review. International Journal of Machine Tools and Manufacture Vol. 51(2011) pp. 363-376.
26. Rashid M.K. : Simulation Study on the Improvements of Machining Accuracy by Using Smart Materials. Robotics and Computer-Integrated Manufacturing Vol. 21(2005) pp. 249-257.
27. Sellmeier V. Denkena B.: High speed process damping in milling. CIRP Journal of Manufacturing Science and Technology Vol. 5 (2012) pp. 8-19.
28. Siemiątkowski M. Przybylski W. : Simulation studies of process flow with in-line part inspection in machining cells. Journal of Materials Processing Technology January 10 2006 Vol. 171 Issue 1 pp. 27-34.
29. Soliman E. Ismail F. : Chatter suppression by adaptive speed modulation. International Journal of Machine Tools and Manufacture Vol. 37(1997) pp. 355-369.
30. Tomków J. : Vibrostability of machine tools (in Polish) The Scientific and Technical Publications Warsaw 1997. Plik : PMR-spec_KK_M..: 33256 zn. norm. [185 str] stan 2017-02-06 kor. epw