Abstract The dynamic characteristics is an important index to measure the performance of machine tools.However, there is no better method to evaluate the dynamic characteristics of whole NC (numerical control) machine tool. Through the excitation of real dynamic cutting force to the NC machine tool, the dynamic characteristics of the machine tool under the action of cutting force can be quickly obtained. In view of the fact that the cutting parameters would affect the amplitude of cutting force corresponding to each frequency component, a dynamic excitation force model was established based on the dynamic cutting forces under different sample materials and cutting parameters.The dynamic characteristics of the NC machine tool in different frequency bands could be tested by frequency band excitation. Through the finite element simulation analysis, the dynamic characteristics of NC machine tool in each frequency band was judged. The main frequency components in the vibration of machine tool were obtained by fast Fourier transform of vibration signal, which could provide guidance for optimizing the dynamic characteristics of machine tool. The dynamic stiffness of different machine tools under excitation of various dynamic cutting forces was compared to distinguish which machine tool had better dynamic characteristics. Finally, the simulation results were verified by the excitation test. The results indicate that the above method is simple and practical, and can quickly evaluate the dynamic characteristics of NC machine tool, which has certain practical value.
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