Correction of dynamic effects on force measurements made with piezoelectric dynamometers

An original method for measuring dynamic forces using a commercial piezoelectric dynamometer is presented. This approach is based on the construction of a correction function taking into account the dynamic behavior of the mechanical environment: milling machine, measuring device and workpiece assembly. It allows measurement of the cutting forces for a large frequency domain exceeding the bandwidth of the piezoelectric dynamometer used. Through the located excitations, the complex equation of Transmissibility between the cutting forces and the dynamometer measurements is obtained. The methodology has been applied for a three-component commercial dynamometer fixed on a milling machine. It has been validated by means of the addition of controlled sinusoidal excitations. This method has applications in high-speed machining and in cutting processes involving instabilities.