https://escholarship.org/content/qt4h56k1ch/qt4h56k1ch.pdf

Advanced monitoring of machining operations

Chatter is a self-excited vibration that can occur during machining operations and become a common limitation to productivity and part quality. For this reason, it has been a topic of industrial and academic interest in the manufacturing sector for many years. A great deal of research has been carried out since the late 1950s to solve the chatter problem. Researchers have studied how to detect, identify, avoid, prevent, reduce, control, or suppress chatter. This paper reviews the state of research on the chatter problem and classifies the existing methods developed to ensure stable cutting into those that use the lobbing effect, out-of-process or in-process, and those that, passively or actively, modify the system behaviour.

Chatter in machining processes: A review

Chatter Stability of Metal Cutting and Grinding

Recent advances in modelling of metal machining processes

SUMMARY The paper presents an ecient numerical method for the stability analysis of linear delayed systems. The method is based on a special kind of discretization technique with respect to the past eect only. The resulting approximate system is delayed and also time periodic, but still, it can be transformed analytically into a high-dimensional linear discrete system. The method is applied to determine the stability charts of the Mathieu equation with continuous time delay. Copyright ? 2002 John Wiley & Sons, Ltd.

/pdf/semi-discretization-method-for-delayed-systems-xm2qp1dyet.pdf

Semi‐discretization method for delayed systems

Traditional regenerative stability theory predicts a set of optimally stable spindle speeds at integer fractions of the natural frequency of the most flexible mode of the system. The assumptions of this theory become invalid for highly interrupted machining, where the ratio of time spent cutting to not cutting (denoted p) is small. This paper proposes a new stability theory for interrupted machining that predicts a doubling in the number of optimally stable speeds as the value of p becomes small. The results of the theory are supported by numerical simulation and experiment. It is anticipated that the theory will be relevant for choosing optimal machining parameters in high-speed peripheral milling operations where the radial depth of cut is only a small fraction of the tool diameter.

Stability Prediction for Low Radial Immersion Milling

The Stability of Low Radial Immersion Milling

On the Dynamics of High-Speed Milling with Long, Slender Endmills

The purpose of this study is an evaluation of the statistical variance in the once-per-revolution sampled audio signal during milling as a chatter indicator. It is shown that, due to the synchronous and asynchronous nature of stable and unstable cuts, respectively, once-per-revolution sampling leads to a tight distribution of values for stable cuts, with a corresponding low variance, and a wider sample distribution for unstable cuts, with an associated high variance. A comparison of stability maps developed using: 1) analytic techniques, and 2) the variance from once-per-revolution sampled time-domain simulations is provided and good agreement is shown. Experimental agreement between the well-known Fast Fourier Transform (FFT) chatter detection method, that analyzes the content of the FFT spectrum for chatter frequencies, and the new variance-based technique is also demonstrated.

Exploring once-per-revolution audio signal variance as a chatter indicator

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1418&context=mechengfacpub

Brian S. Dutterer

Papers

Stability Prediction for Low Radial Immersion Milling

The Stability of Low Radial Immersion Milling

On the Dynamics of High-Speed Milling with Long, Slender Endmills

Exploring once-per-revolution audio signal variance as a chatter indicator

Sacrificial Structure Preforms for Thin Part Machining