DYNAMIC PERFORMANCE IMPROVEMENT OF AN ELECTRICAL-DISCHARGE MACHINE USING AN EXPERIMENTAL-DESIGN METHOD AND EXPERIMENTAL MODAL-ANALYSIS

Abstract

An orthogonal array method is used in the design of experimental variables for the identification of their effects on the dynamics of the tool-head system of an electrical discharge machine. The purpose of the identification was to develop formulae for the prediction of resonant frequencies under a given configuration of the machine, so that the servo motor driving frequency at which the tool-head system was excited in the vertical direction could be maximized. Modal tests were carried out on the tool-head system to determine the weakest point of the most problematic dynamic mode and it was found to be the tool clamping device, which was therefore modified. The improvements are shown in terms of the resonant frequencies, the vibration magnitudes and the mode shapes.