Measurement of ultrasonic-frequency repetitive impulse cutting force signal

Abstract

An innovative system for measuring ultrasonic-frequency repetitive impulse cutting force signals is proposed in this paper. Compared with the traditional cutting force measurement methods, it can realize the measurement of the transient cutting force signal of around 20 KHz rather than the average cutting force. A piezoelectric force sensor of a resonant frequency around 180 KHz is used instead of the traditional dynamometers that only can measure the cutting force signal of no more than 500 Hz. Besides, a clamp circuit is used to stabilize the decayed repetitive impulse signal due to the characteristic of piezoelectric sensors. After building the measurement system, experiments and finite element simulations are carried out based on an orthogonal one-directional ultrasonic vibration cutting model, respectively. The results have validated this proposed measurement system through force signal shapes, values of duty cycle and average cutting forces. In this regard, the separation effect of ultrasonic vibration cutting is firstly detected and the cutting process during one vibration cycle can be monitored through the measured transient cutting force signal, both of which will be great significant to the further researches for the deeper understanding of the machining mechanism influenced by the ultrasonic vibration.