Cutting force sensor based on digital image correlation for segmented chip formation analysis

Conventional piezoelectric sensors cannot record the force fluctuations at high frequencies to monitor serrated chip formation. Recently, force measurements by using digital image correlation (DIC) have been reported thanks to imaging devices that become more and more efficient, thereby opening possibilities of high rate acquisition. This study proposes to apply DIC based on closed-form solutions in order to measure cutting forces at camera acquisition frequency. The considered displacement fields are obtained from the Flamant–Boussinesq solution. This method is first applied to picture pairs shot during the cut and then to a full sequence of pictures recorded upon orthogonal cutting of hardened AISI 52100 steel with a c-BN tool. To validate part of the corresponding mechanism, the change of cutting forces is finally investigated when chip segments are formed.