Supplementary file 2_Dynamic modeling and frequency response characteristic analysis of a heavy boring machine tool post system based on 5-DOF.docx

Finite element method (FEM) simulations show that the natural frequencies of the tool post system are 7.6621 Hz, 12.483 Hz, 24.179 Hz, 31.214 Hz, and 41.268 Hz, with a maximum error of 0.31%. This close agreement further verifies the effectiveness of the theoretical modeling. Using theoretical calculations of the stiffness and damping parameters of each joint of the tool post system, the transient analysis of the first three natural frequencies is carried out by FEM.

The deformation of each structure of the tool post system at different frequencies is obtained. At an excitation frequency of 7 Hz, the maximum deformation of the tool holder is 4.8 mm. These findings clarify that lowfrequency excitation strongly influences the tool holder's vibration characteristics.

In order to reduce the vibration of the tool holder, the damping characteristics of the tool post system are analyzed using FEM. The results of comparing the transient response of the tool holder under damping ratios of 0.01, 0.03, and 0.05 show that the damping ratio influences the tool holder amplitude under low-frequency excitation. The research results provide support for the design and optimization of heavy machine tools.</p>