Volume 18, No. 6, 2021
Stability Lobe Diagram For Optimization Of Turning Chatter In Machining
Akshat Singh Jhala , Dr. Manish Pokharna
Abstract
This paper investigates some fundamentals of vibration in cutting tools. It has been reported that chatter phenomenon may be the result of both self-induced and forced vibration where self-induced vibration is considered to be a function of the cutting properties of the metal and the sharpness of the tool, while the forced vibration depends on the interference of the tool with the surface cut during previous revolutions. There are some speed, frequency, and sharpness restrictions in place, with vibration being infrequently seen at low cutting speeds, high tool frequencies, or with recently lapped tools. Self-excited regenerative vibration or chatter limits the primary requirements like productivity, surface finish and dimensional accuracy of high-speed machining. The most dependable strategy for reducing and eliminating chatter is to choose the machining settings using a stability lobe diagram. Knowing particular cutting force coefficients and tool point frequency response functions (FRFs) is often required to produce stability lobe diagrams. Stability lobe diagrams' stable zones are greatly impacted by improper tool point FRF use. Plotting the stability limits and chatter frequency results in the stability lobe diagram for the developed theoretical model. The Transfer Function (TF) or Frequency Response Function (FRF) of the machine tool-tool holder-tool system gives the system the essential data (dynamic characteristics). High quality microphone to record the vibration was used to track the chatter reaction. The natural frequency, modal stiffness, and damping coefficient of the tool vibration, which are typically obtained by the frequency response function (FRF) of the system, have been calculated in order to create the stability lobe diagram of the tool vibration. The project envisase to find solution to improve the material removal rate without compromising the surface fisnish and machining tolerance of the workpiece, which compeled to consider the prediction model of MRR and chatter severity. These two factors have been developed and analysed to obtain optimal stablerange of turning parameters with lower chatter and improved material removal rate so that quality ahd accuracy could be mainained with high productivity.
Pages: 9107-9130
Keywords: Stability lobe diagram, SLD, Chatter, vibration, turning, CNC lathe, OMA, Operational model analysis, regenerative vibration, self-excited vibration.