A technique for applying the symmetry method to solve a problem of torsional vibrations of disks of variable thickness

Authors

DOI:

https://doi.org/10.15587/1729-4061.2025.323561

Keywords:

differential equation, disk of variable thickness, torsional vibrations, natural frequencies, method of symmetries

Abstract

The object of this study is a disk of variable thickness. A solution to the problem of natural torsional vibrations of disks of variable thickness was sought. An algorithm to solve the problem for an arbitrary number of different disk profiles has been constructed. The law of change in disk thickness H(ρ), which contains three arbitrary constants α, С, С1, has been considered. The choice of the disk profile configuration is controlled by changing the values of these three constants.

Exact solutions to the problem in elementary functions are known only in two cases, when H(ρ)=1/ρ3 or H(ρ)=ρ-3eαρ, where ρ is the relative radial coordinate and α is an arbitrary constant. These cases are not sufficient for generalizing conclusions about the behavior of disks during their oscillations.

For the case of a disk that is rigidly fixed along its inner diameter and with a free outer edge, the corresponding relations were derived. They made it possible to calculate natural numbers and study the distribution of angular displacements of the disk. These numerical parameters, along with the frequency indices, are a convenient technique for evaluating the resonant properties of the disk for practice.

A comparison of torsional and radial vibrations of the disk with the chosen law of thickness change was performed. To study torsional vibrations, approximation approaches of thickness change functions were used. It was found that the relative discrepancy between the values of these functions at a certain interval did not exceed 2.2 %. It was found that the differences in the eigenfrequencies of torsional vibrations for the disk of the chosen configuration were significantly smaller than in the case of radial vibrations.

A practical algorithm for applying the method used is presented, which could prove useful for further research based on similar analytical approaches.

The method makes it possible to choose the desired disk configuration for various practical purposes. Owing to this feature, it is possible to provide the required distribution of cyclic stresses, resonant frequencies, and amplitudes for the disk

Author Biographies

Kirill Trapezon, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute"

PhD, Associate Professor

Department of Acoustic and Multimedia Electronic Systems

Alexandr Trapezon, G. S. Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine

Doctor of Technical Sciences, Leading Research

Department No. 6

References

  1. Kumar, P., Tiwari, R. (2023). A review: multiplicative faults and model-based condition monitoring strategies for fault diagnosis in rotary machines. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 45 (5). https://doi.org/10.1007/s40430-023-04203-z
  2. Murawski, L., Dereszewski, M. (2019). Theoretical and practical backgrounds of monitoring system of ship power transmission systems’ torsional vibration. Journal of Marine Science and Technology, 25 (1), 272–284. https://doi.org/10.1007/s00773-019-00646-z
  3. Kim, Y. G., Kim, U. K. (2019). Effects of torsional vibration of a propulsion shafting system and energy efficiency design index from a system combining exhaust gas recirculation and turbocharger cut out. Journal of Mechanical Science and Technology, 33 (8), 3629–3639. https://doi.org/10.1007/s12206-019-0703-5
  4. Bai, B., Zhang, J., Cui, Y., Li, H. (2020). Vibration characteristics investigation of mistuned blisks with receptance substructure component modal synthesis method. Journal of Mechanical Science and Technology, 34 (7), 2715–2729. https://doi.org/10.1007/s12206-020-0604-7
  5. Kutsal, S. M., Coşkun, S. B. (2023). Analytical approximations for elastic limit angular velocities of rotating annular disks with hyperbolic thickness. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 45 (6). https://doi.org/10.1007/s40430-023-04132-x
  6. Salehian, M., Shahriari, B., Yousefi, M. (2018). Investigating the effect of angular acceleration of the rotating disk having variable thickness and density function on shear stress and tangential displacement. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 41 (1). https://doi.org/10.1007/s40430-018-1523-8
  7. Szuwalski, K., Ustrzycka, A. (2015). Mathematical and numerical modelling of large creep deformations for annular rotating disks. Applied Mathematics and Mechanics, 36 (11), 1441–1448. https://doi.org/10.1007/s10483-015-1994-7
  8. Bagheri, E., Asghari, M., Danesh, V. (2019). Analytical study of micro-rotating disks with angular acceleration on the basis of the strain gradient elasticity. Acta Mechanica, 230 (9), 3259–3278. https://doi.org/10.1007/s00707-019-02461-4
  9. Thakur, P., Sethi, M., Kumar, N., Gupta, K., Bhardwaj, R. K. (2021). Analytical Solution of Hyperbolic Deformable Disk having Variable Density. Mechanics of Solids, 56 (6), 1039–1046. https://doi.org/10.3103/s0025654421060194
  10. Bahrami Babamiri, B., Shahrjerdi, A., Bayat, M. (2020). Effect of geometrical imperfection on the thermomechanical behavior of functionally graded material rotating disk. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 42 (5). https://doi.org/10.1007/s40430-020-02360-z
  11. Biezeno, C. B., Grammel, R. (1939). Technische Dynamik. Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-662-36257-0
  12. Trapezon, K., Trapezon, A., Kalinichenko, V., Didkovskii, V. (2024). Results of the analytical solution of the problem of radial vibrations of disks of variable thickness. Eastern-European Journal of Enterprise Technologies, 2 (7 (128)), 6–15. https://doi.org/10.15587/1729-4061.2024.300090
  13. Kamke, E. (1959). Differential gleichungen, Losungsmethoden und losungen. Leipzig, 244.
A technique for applying the symmetry method to solve a problem of torsional vibrations of disks of variable thickness

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Published

2025-04-29

How to Cite

Trapezon, K., & Trapezon, A. (2025). A technique for applying the symmetry method to solve a problem of torsional vibrations of disks of variable thickness. Eastern-European Journal of Enterprise Technologies, 2(7 (134), 6–14. https://doi.org/10.15587/1729-4061.2025.323561

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Section

Applied mechanics