Free Flexural Vibration Studies on Skew Plates

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. The transducer realizes broadband transmission by means of the coupling between radial vibration of the piezoelectric rings and high-order flexural vibration of the spherical cap metal shells. The low-frequency directional transmission of the transducer is realized by using excitation signals with different amplitude and phase on two mosaic piezoelectric rings. The relationship between transmitting voltage response (TVR), resonance frequency and structural parameters of the transducer is analyzed by finite element software COMSOL. The broadband performance of the transducer is also optimized. On this basis, the low-frequency directivity of the transducer is further analyzed and the ratio of the excitation signals of the two piezoelectric rings is obtained. Finally, a prototype of the broadband ring flextensional underwater transducer is fabricated according to the results of simulation. The electroacoustic performance of the transducer is tested in an anechoic water tank. Experimental results show that the maximum TVR of the transducer is 147.2 dB and the operation bandwidth is 1.5–4 kHz, which means that the transducer has good low-frequency, broadband transmission capability. Meanwhile, cardioid directivity is obtained at 1.4 kHz and low-frequency directivity is realized.

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Reduction of Carbody Flexural Vibration by the High-damping Elastic Support of Under-floor Equipment

Quarterly Report of RTRI ◽

10.2219/rtriqr.56.4_262 ◽

2015 ◽

Vol 56 (4) ◽

pp. 262-267 ◽

Cited By ~ 1

Author(s):

Ken-ichiro AIDA ◽

Takahiro TOMIOKA ◽

Tadao TAKIGAMI ◽

Yuki AKIYAMA ◽

Hiroyuki SATO

Keyword(s):

Flexural Vibration ◽

Elastic Support

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An Improvement of the Myklestad Method for Flexural-Vibration Problems

Journal of the Aerospace Sciences ◽

10.2514/8.7917 ◽

1959 ◽

Vol 26 (1) ◽

pp. 46-50 ◽

Cited By ~ 4

Author(s):

S. MAHALINGAM

Keyword(s):

Flexural Vibration ◽

Vibration Problems

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The Bending, Buckling, and Flexural Vibration of Simply Supported Polygonal Plates by Point-Matching

Journal of Applied Mechanics ◽

10.1115/1.3641670 ◽

1961 ◽

Vol 28 (2) ◽

pp. 288-291 ◽

Cited By ~ 51

Author(s):

H. D. Conway

Keyword(s):

Hydrostatic Pressure ◽

Boundary Conditions ◽

Flexural Vibration ◽

Frequency Equation ◽

Numerical Results ◽

Special Technique ◽

Point Matching ◽

Buckling Loads ◽

Simply Supported ◽

Flexural Vibrations

The bending by uniform lateral loading, buckling by two-dimensional hydrostatic pressure, and the flexural vibrations of simply supported polygonal plates are investigated. The method of meeting the boundary conditions at discrete points, together with the Marcus membrane analog [1], is found to be very advantageous. Numerical examples include the calculation of the deflections and moments, and buckling loads of triangular square, and hexagonal plates. A special technique is then given, whereby the boundary conditions are exactly satisfied along one edge, and an example of the buckling of an isosceles, right-angled triangle plate is analyzed. Finally, the frequency equation for the flexural vibrations of simply supported polygonal plates is shown to be the same as that for buckling under hydrostatic pressure, and numerical results can be written by analogy. All numerical results agree well with the exact solutions, where the latter are known.

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