Proposal of “specific cutting displacement coefficient” concept and its operational identification in milling - Part 2: Experimental validation

In Part 2 of this paper, the proposed “specific cutting displacement coefficient” concept is validated experimentally. This coefficient is the product of the specific cutting force and dynamic compliance of the flexible system, and in Part 1 of this paper the operational identification of it in milling, i.e., D-matrix, was proposed which only utilized the measured forced vibration; the utilization of high-cost dynamometers and impact hammers can be eliminated. In addition, the D-matrix was applied to the stability lobe analysis, which automatically reflects the operational state of the flexible system, e.g., tool-holder-spindle system. In this part, the proposed concept is validated experimentally by measuring the forced vibration during milling, and it is applied to the stability lobe analysis and spindle-condition monitoring. As a result, a clear lobe shift in high spindle speeds is observed due to the operational state of the system, and chatter tests confirm that the predicted stability lobes by the proposed method agree well with the experimental results; the stability lobes can be predicted without utilization of force sensors.