Experimental Methodology for Discretization and Characterization of the Rigidities for Large Components Manufacturing Machines

Force, vibration and deformation models are more and more used to improve accuracy in machining operations. This improvement is more remarkable, the higher the scale on which the machine work, due to the tolerances and decrease of stiffness of this type of machines. But to feed these models is necessary to characterize the stiffness of the machine. To perform theoretically this characterization using finite elements is in general very difficult and sometimes impossible because the user often does not know the structural characteristics of the machine.Commonly, the experimental method is imposed as the best approach. This paper presents a methodology to determine the lowest number of degrees of freedom and stiffness for each and validates the proposed methodology on a real case in a vertical lathe in a boring operation.