Operational modal analysis used to identify dynamic behaviour of machine tools during milling

The dynamic behaviour of machine tools during cutting is investigated by Operational Modal Analysis (OMA), which overcomes the disadvantages of the Experimental Modal Analysis (EMA) using excitation methods such as shakers or hammers, not considering effects occurring during operation. The assumptions of OMA such as time-invariance and white noise excitation are difficult to fulfil considering the boundary conditions of a milling process. The results show that feed motions classify the varying dynamic behaviour in the working space and excitation is controlled by modification of the milling conditions. Modal Parameters, identified by OMA, provide process-related results enabling to improve performance.