Results of the analytical solution of the problem of radial vibrations of disks of variable thickness

Authors

DOI:

https://doi.org/10.15587/1729-4061.2024.300090

Keywords:

disk of variable thickness, radial vibrations, natural frequencies, waveforms, stresses

Abstract

An analytical solution is obtained for the problem of radial vibrations of disks of variable thickness. A disk is considered that is rigidly fixed along the inner circular contour (ρ=0.2) and free on the outer contour (ρ=1). The thickness of the disk varies according to the law H=H0ν+μ+Cρν-μ)2, where H0,C,μ are arbitrary constants; ν is the Poisson's ratio. The exact solution of the problem is known only for H=const and H=1/ρ3. However, these solutions are not sufficient to study the vibrations of disks of other configurations. The proposed law of thickness variation H(ρ) allows us to obtain exact solutions to the problem at any value of the constant coefficients H0, C, μ, ν. By varying the values of these coefficients within a single given function, it is possible to set the disk profile of the desired appearance. The methods used to obtain these solutions are based on appropriate mathematical transformations of the original equation.

The problem of disk oscillations is solved for four variants of thickness change. The natural frequencies for the first three forms of vibration are calculated. Comparison of the natural frequencies found for the three cases of the disk profile gently sloping indicates an increase in their values with an increase in the bending of the disk thickness. Based on the obtained eigenfunctions, the stresses were calculated and the nature of their distribution along the radial coordinate of the disk was determined.

The strength of the disks under resonant radial vibrations was evaluated using a special criterion. It is found that the most limiting, i.e., destructive principal stress σ1r at the first (main) form of vibration should be chosen from the ratio σr≈0.79 [σ-1], where [σ-1] is the endurance limit of the disk material under uniform loading. The results obtained can be used to predict the stress-strain state of disks of variable profile under their radial vibrations

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

Vitalii Kalinichenko, G. S. Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine

PhD, Senior Researcher

Department No. 6

Vitaliy Didkovskii, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute"

Doctor of Technical Sciences, Professor

Department of Acoustic and Multimedia Electronic Systems

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Results of the analytical solution of the problem of radial vibrations of disks of variable thickness

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Published

2024-04-30

How to Cite

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

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Section

Applied mechanics