Tesis de maestría
Stability analysis of multi-degree of freedom systems in milling operations: Altintas analytical method vs. chebyshev polynomial approximation-Edición Única
Fecha
2006-12-01Autor
Araya Pérez, Francisco Javier
Institución
Resumen
Chatter phenomena, essentially known as forced and self excited (regenerative)
vibration, has long been a problem in machining operations. Many approaches
trend to predict the limits of stable zones based on predictive machine tool
chatter vibration theory derived by Tobias and Fishwick (S. A. Tobias, and W.
Fishwick, 1958) and Tlusty (Tlusty, J. and F. Ismail, 1981). Different mechanistic
models of exciting forces on the machine tool interface has been developed and
compared with experimental data. However, since the dynamic cutting force is
strongly influenced by the cutting parameters of the process, a great number of
variations can be presented when machining a workpiece in milling operations.
The importance of chatter study comes from productivity issues related to
machining industry. Since the generated vibration affects the surface finish and
dimensional accuracy of the workpiece, tool life and even machine life due to
excessive wear, chatter becomes both quality and production issues that affect
the cost of productivity of a Company. Thus, solutions to chatter problems have
become increasingly important in manufacturing industry. Though chatter is
simply a consequence of vibration within a machining system, finding causes for
the vibration and developing corrective strategies is the main scope of chatter
problems.
The analytical method developed by Altintas is one of the most used to compute
stability zones in milling operations. In this document, we use the Chebyshev
approximation method, and compare the results with those obtained by Altintas
(Altintas and Budak, 1998), Stepan (Stepan, et. al. 2002 (a)) and De LaCalle (De
LaCalle, 2005). The stability analysis was done for one, two and three degree of
freedom systems of milling operations.