The Ritz method is applied in a three-dimensional (3-D) analysis to obtain accurate frequencies for thick circular and annular plates. The method is formulated in a manner which allows one to have any combination of free or fixed plate boundaries. Admissible functions for the three displacement comp
Three-dimensional vibration analysis of thick, circular and annular plates with nonlinear thickness variation
โ Scribed by Jae-Hoon Kang
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 398 KB
- Volume
- 81
- Category
- Article
- ISSN
- 0045-7949
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โฆ Synopsis
A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of thick, circular and annular plates with nonlinear thickness variation along the radial direction. Unlike conventional plate theories, which are mathematically two-dimensional (2-D), the present method is based upon the 3-D dynamic equations of elasticity. Displacement components u s , u z , and u h in the radial, thickness, and circumferential directions, respectively, are taken to be sinusoidal in time, periodic in h, and algebraic polynomials in the s and z directions. Potential (strain) and kinetic energies of the plates are formulated, and the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies by minimizing the frequencies. As the degree of the polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies of the plates. Numerical results are presented for completely free, annular and circular plates with uniform, linear, and quadratic variations in thickness. Comparisons are also made between results obtained from the present 3-D and previously published thin plate (2-D) data.
๐ SIMILAR VOLUMES
Three-dimensional vibrations of thick circular and annular plates are analyzed by a "nite element method which, with a properly assumed set of displacement "eld, is di!erent from the traditional 3-D "nite element analysis and is reduced to a sequence of 2-D analyses one for each circumferential wave