Takuji Magara

System Identification of Wire Electrical Discharge Machining

Abstract In wire electrical discharge machining (wire-EDM), it is very important to restrain the vibration of the tool wire electrode for the improvement of machining accuracy. In this paper, investigation is carried out toward the dynamic wire vibration mechanism and a mathematical model is derived. This model is compared with experimental results. The measured displacement of a wire electrode in machining a thin plate is analyzed with impulsive force measured through impulse response by a single discharge. The force acting on the wire depends on the direction of the wire movement in vibration. A 3rd order system equation for the wire EDM system is derived considering machining removal and vibrational features of the system are discussed with the equation. As the discharge circuit suddenly changes according to gap condition, this vibration system is essentially nonlinear. Simulation of wire-EDM is performed with the modeled system.