A new method for identification and modeling of process damping in machining

Abstract

Process damping is usually ignored in chatter stability analysis as there is no practical model for estimation of the damping coefficient and very limited data is available. This is mainly because of the fact that complicated test set-ups were used in order to measure the damping force in the past. In this study, practical identification and modeling methods for the process damping are presented. In this approach, the process damping is identified directly from the chatter tests using the experimental and the analytical stability limits. Once the process damping coefficient is identified, it is related to the instantaneous indentation volume by an indentation coefficient which is a more general constant, and thus can be used for different cutting conditions and tool geometries. In determination of the indentation coefficient, chatter test results, energy analysis and tool workpiece indentation geometry analysis are used. The determined coefficients are used for the stability limit prediction in different cases for verification. The presented method can be used to determine the chatter-free cutting depths under the influence of process damping for increased productivity.