Cutting force modeling and accurate measurement in milling of flexible workpieces

•Workpiece flexibility causes significant distortions in the measured cutting forces.•The inverse-based filtering method enables to correct distorted cutting force data.•The compensated and predicted cutting forces are in good agreement.•Cutting force compensation accuracy is affected by alteration in workpiece dynamics. This paper presents the cutting force modeling and the experimental verification for the model with the accurate measurement of the milling forces through the dynamic compensation of the workpiece-dynamometer assembly dynamics in the milling of the flexible workpieces. To this end, time domain simulation containing both the tool and workpiece dynamics in two directions and a mechanistic force model are used to numerically estimate the cutting forces. Single and two degree of freedom flexure stages, which represent the workpiece flexibility, were designed and constructed to perform the experimental validation. For the accurate measurement of the cutting forces, inverse-based filtering compensation method is employed. It has been found that the measured cutting forces are significantly distorted by the workpiece flexibility and they can not provide reliable information about the milling mechanics and dynamics. However, by the use of the inverse-based filtering approach, the actual cutting forces acting on the tool/workpiece have been accurately obtained and they are in reasonable agreement with the computed ones. Furthermore, it has been observed that the variation in the workpiece dynamics due to the material removal in the milling plays a crucial role for the accurate cutting force compensation.