Abstract
The main spindle is the most important part of the machine tool making the rotation tool needed to remove material in the chips form. The spindle is directly exposed to the vibration generated by the cutting process. These vibrations can be both sinusoidal and random. In this paper we shall consider the behavior of the main spindle to the random cutting vibration (RCV). Finite element method was used to highlight the dynamic behavior in different cases: free and processing. To validate the results of the numerical simulation an experimental protocol is achieved by determining the natural frequency for each direction of the main spindle. Keywords: Finite Element Modeling, random vibration, spindle.