NATURAL FREQUENCIES AND MODES OF FREE-EDGE CIRCULAR PLATES VIBRATING IN VACUUM OR IN CONTACT WITH LIQUID

1995 ◽  
Vol 188 (5) ◽  
pp. 685-699 ◽  
Author(s):  
M. Amabili ◽  
A. Pasqualini ◽  
G. Dalpiaz
Keyword(s):  
Natural Frequencies ◽  
Free Edge ◽  
Circular Plates ◽  
Natural Frequencies And Modes

scholarly journals Natural frequencies of orthotropic circular plates of variable thickness.

AIAA Journal ◽  
1968 ◽  
Vol 6 (8) ◽  
pp. 1625-1626 ◽  
Author(s):  
ALAN P. SALZMAN ◽  
SHARAD A. PATEL
Keyword(s):  
Variable Thickness ◽  
Natural Frequencies ◽  
Circular Plates ◽  
Plates Of Variable Thickness

scholarly journals INFLUENCE OF A LIQUID ON THE NATURAL FREQUENCIES OF ALMOST CIRCULAR PLATES

2014 ◽  
Vol 06 (05) ◽  
pp. 1450052 ◽  
Author(s):  
MANUEL GASCÓN-PÉREZ ◽  
PABLO GARCÍA-FOGEDA
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Mode ◽  
Normal Modes ◽  
Virtual Mass ◽  
Circular Plates ◽  
Hankel Transformation ◽  
Fluid System ◽  
Surrounding Fluid ◽  
Good Agreement

In this work, the influence of the surrounding fluid on the dynamic characteristics of almost circular plates is investigated. First the natural frequencies and normal modes for the plates in vacuum are calculated by a perturbation procedure. The method is applied for the case of elliptical plates with a low value of eccentricity. The results are compared with other available methods for this type of plates with good agreement. Next, the effect of the fluid is considered. The normal modes of the plate in vacuum are used as a base to express the vibration mode of the coupled plate-fluid system. By applying the Hankel transformation the nondimensional added virtual mass 2 increment (NAVMI) are calculated for elliptical plates. Results of the NAVMI factors and the effect of the fluid on the natural frequencies are given and it is shown that when the eccentricity of the plate is reduced to zero (circular plate) the known results of the natural frequencies for circular plates surrounded by liquid are recovered.

Natural frequencies of monoclinic circular plates

1974 ◽  
Vol 55 (4) ◽  
pp. 874-876
Author(s):  
J. Padovan ◽  
J. Lestingi
Keyword(s):  
Natural Frequencies ◽  
Circular Plates

Natural Frequencies and Modes of Beams

2014 ◽  
pp. 89-112
Author(s):  
Sinniah Ilanko ◽  
Luis E. Monterrubio ◽  
Yusuke Mochida
Keyword(s):  
Natural Frequencies ◽  
Natural Frequencies And Modes

Spatial Modulation of Repeated Vibration Modes in Rotationally Periodic Structures

1997 ◽  
Author(s):  
Mintae Kim ◽  
Joonho Moon ◽  
Jonathan A. Wickert
Keyword(s):  
Mode Shape ◽  
Natural Frequencies ◽  
Periodic Structures ◽  
Spatial Modulation ◽  
Vibration Modes ◽  
Algebraic Relation ◽  
Natural Frequencies And Modes ◽  
Axisymmetric Structure ◽  
Technical Interest ◽  
Model Features

Abstract When a structure deviates from axisymmetry because of circumferentially varying model features, significant changes can occur to its natural frequencies and modes, particularly for the doublet modes that have non-zero nodal diameters and repeated natural frequencies in the limit of axisymmetry. Of technical interest are configurations in which inertia, dissipation, stiffness, or domain features are evenly distributed around the structure. Aside from the well-studied phenomenon of eigenvalue splitting, whereby the natural frequencies of certain doublets split into distinct values, modes of the axisymmetric structure that are precisely harmonic become contaminated by certain additional wavenumbers in the presence of periodically spaced model features. From analytical, numerical, and experimental perspectives, this paper investigates spatial modulation of the doublet modes, particularly those retaining repeated natural frequencies for which modulation is most acute. In some cases, modulation can be sufficiently severe that a mode shape will beat spatially as harmonics with commensurate wavenumbers combine, just as the superposition of time records having nearly equal frequencies leads to classic temporal beating. A straightforward algebraic relation and a graphical checkerboard diagram are discussed with a view towards predicting the wavenumbers present in modulated eigenfunctions given the number of nodal diameters in the base mode and the number of equally spaced model features.

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