Vol.1, No 5, 1998 pp. 581 - 593
UDC:621.91:621.3.018
THE CHATTER VIBRATIONS IN METAL CUTTING
-THEORETICAL APPROACH
Ivana Kovačić
University of Novi Sad, Faculty of Technical Sciences, Department of
Mechanics
Trg Dositeja Obradovica 6, 21000 Novi Sad, Yugoslavia
Abstract. In this paper an appearance of chatter vibrations in metal
cutting is investigated. The model of the system is based on the predictive
machine theory of shear zone model. Since the dynamic cutting force is
strongly influenced by the variations of cutting parameters, the objective
of present paper is to consider the variations of rake angle and shear
angle during feeding rate change, and to propose modified nonlinear model
of cutting force and, consequently, nonlinear analytical model of chatter.
By analysing the analytical solution of the governing equation three kinds
of oscillatory motion are found. For each of them the variations of cutting
force component (thrust force) and rake angle as a function of time are
obtained numerically.
Key words: metal cutting, chatter vibrations
SAMOPOBUDNE OSCILACIJE U PROCESU REZANJA
METALA - TEORIJSKI PRILAZ
Ovaj rad se bavi proučavanjem pojave samopobudnih oscilacija u procesu
rezanja metala. Model sistema je baziran na teorijskom pristupu deformisanja
metala u zoni smicanja. Kako je dinamička sila zavisna od vrednosti parametara
rezanja, u ovom radu se razmatra uticaj koji na nju ima promena grudnog
ugla i ugla smicanja tokom promene dubine rezanja, i formira modifikovani
nelinearni model sile rezanja a, posledično, i nelinearni analitički model
samopobudnih oscilacija. Analizom analitičkog rešenja utvrđeno je postojanje
tri moguća slučaja oscilatornog kretanja alata. Za svaki od njih je numeričkim
putem određena promena kompomnente sile rezanja (sile prodiranja) i grudnog
ugla tokom vremena.
