Study for the Identification of Dominant Frequencies and Sensitive Structure on Machine Tools Using Modal Decoupling and Structural Sensitivity Analysis

Background The research on machine tool vibration has significant impact to improve the processing quality of the processed parts. The vibration response on the surface quality is quite different based on different modes of vibration. Purpose Current study proposed a new approach of modes decoupling based on Operational Deflection Shape (ODS) and structural sensitivity analysis, which used to identify the structural vibrations on surface topography in manufacturing process. Method According to the modes decoupling based on the ODS method, the dominant vibration frequencies of machine tool are identified in a wide range of frequency band. Furthermore, the modal mass distribution matrix analysis is used to determine the sensitive structures that cause greater machining errors. A milling process is used to conduct experiments. Results The experimental and theoretical results indicate that (i) the contribution of dominant vibration frequency to the vibration of machine tool is larger than weak modes vibration and (ii) the sensitive structure has higher vibration energy than the insensitive structures. Conclusion The multimode vibration at dominant frequencies of the sensitive structures (MVDFSS) directly can determine the surface topography of the products.