Atsutoshi Hirao

Measurement of Acoustic Emission Wave by Using Optical Fiber Sensor during Microsecond Discharge

In this study, we investigate the effect of discharge current on the occurrence of burst AE wave caused by microsecond discharge. Electrical discharge duration was changed from about 1µs to 8µs by using condenser circuit. Effect of current behavior was estimated by comparing with experimental signal and simulation one. AE wave was detected by optical fiber vibration sensor. The optical fiber vibration sensor is located on an aluminum work-piece (cathode) plate. Simulation was carried out with MSC. Marc. As the results, it was found that AE wave was occurred by a force depending on electrical current behavior. The force direction was machining direction. The force has been occurred during microsecond discharge.

Effect of Arc Discharge Pressure on Discharge Current in EDM

In electrical discharge machining (EDM), an electrical discharge occurs between a tool electrode and a work-piece, and removal of materials is carried out by vaporized explosion between the electrode and the work-piece. However, the mechanism of material removal in EDM is not well understood. In order to clarify this issue, the acoustic emission (AE) method has been applied to examine the force of explosion, and the Schlieren visualization method has been applied to observe the explosion. In this study, we investigate the effect of discharge current behavior on the occurrence of the AE waves by means of an optical fiber vibration sensor.

Effects of Leading and Trailing Edge of Current Pulse on Ae Wave

In this study, the mechanism of pressure occurrence in Electrical discharge machining (EDM) was investigated by Acoustic emission (AE) technique. AE wave was detected by optical fiber vibration sensor during single pulse discharge. This paper describes some experimental results on AE wave characteristics during single pulse discharge. The generation factor and propagation characteristic of AE wave were investigated. Numerical analysis by using finite element method (FEM) was adapted on the assumption that the AE wave was only depending on a force. In order to investigate the effect of current behavior on AE propagation, the numerical analysis result using the FEM and the experimental result along with the single pulse discharge were compared.