Abstract—In the process of boring, the proper selection for the section shape of a boring bar can improve the quality and efficiency of mechanical processing by suppressing its vibration. The boring bar can be simplified as a cantilever beam with variable cross-section. By employing a shape function of the cross-section, the first and second natural frequencies of cantilever beams with different cross-section shapes are investigated via assumed modes method. The influence of the taper and the convexity of the cross section on natural frequency is also analyzed. By solving the principal stiffness and mass of each mode, the influence of the cross-section shape on principal stiffness and mass is studied. By numerical calculating, the influence of the change rate of the corresponding principal stiffness and mass on natural frequency is analyzed. Finally, the design principles of variable cross-section cantilever beam are given.
Index Terms—Conical boring bar, variable cross-section beam, assumed modes method, natural frequency, principal stiffness.
The authors are with College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China (e-mail: 27110292@qq.com, renys@sdust.edu.cn).
[PDF]
Cite: Yao Donghui and Ren Yongsheng, "Natural Frequencies of Conical Boring Bars," International Journal of Materials, Mechanics and Manufacturing vol. 7, no. 6, pp. 265-269, 2019.
Copyright © 2019 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (
CC BY 4.0).