A simplified methodology for finding the natural frequencies and mode shapes of the machine tool structures

Finding the natural frequencies of the machine tool structures is essential so that these can be kept away from the operational frequencies. Modelling and analysis of the actual structures is expensive and time-consuming. This paper presents a simplified, FEM based methodology for approximating the natural frequencies and mode shapes of the machine tools structures. This methodology was used to find the vibration characteristics of a vertical milling machine under different loading conditions. The results showed that an increase in the mass of the workpiece, causes a decrease in its lower-order natural frequencies, but the higher-order natural frequencies remain largely unaffected. (C) 2020 Elsevier Ltd. All rights reserved.