Dynamic modeling of cutting acoustic emission via piezo-electric actuator wave control

The fundamental understanding of the dynamic behavior of acoustic emission signals in relation to machining process parameters plays an important role in the automation monitoring and control of metal cutting operations. This paper presents an analytical model for acoustic emission dynamics in orthogonal cutting with chip thickness variation. An analytical expression for acoustic emission generated in turning is established as an explicit function of the cutting parameters and tool/workpiece geometry. Based on the theoretical static cutting acoustic emission model, the generation of the RMS acoustic emission is formulated as the function of three process parameters, namely tool displacement, cutting speed, and rake angle. The incremental change of the RMS acoustic emission is related to the chip formation process in an elemental cutting area and it is characterized by the dynamic variation of these process parameters. The analysis of the RMS acoustic emission is then extended into the dynamic transfer function between tool displacement and RMS acoustic emission. Experimental results via simultaneous tool displacement control by piezo-electric actuator and measurement of RMS AE generated during cutting confirm the validity of the analytical acoustic emission model in orthogonal cutting process.