PREDICTION OF IMPACT FORCES IN A VIBRATORY BALL MILL USING AN INVERSETECHNIQUE

To understand the dynamic mechanisms of the mechanical milling process in a vibratory mill, it is necessary to determine the characteristics of the impact forces associated with the collision events. However, i t is difficult to directly measure the impact force in an operating mi ll. This paper describes an inverse technique for the prediction of im pact forces from acceleration measurements on a vibratory ball mill. T he characteristics of the vibratory mill have been investigated by the modal testing technique, and its system modes have been identified. I n the modelling of the system vibration response to the impact forces, two modal equations have been used to describe the modal responses. T he superposition of the modal responses gives rise to the total respon se of the system. A method based on an optimisation approach has been developed to predict the impact forces by minimising the difference be tween the measured acceleration of the vibratory ball mill and the pre dicted acceleration from the solution of the modal equations. The pred icted and measured impact forces are in good agreement. Copyright (C) 1996 Elsevier Science Ltd.