Vibration and Damping Analysis of a Multilayered Cylindrical Shell, Part 11: Numerical Results

Alam, Naushad; Asnani, N.T.

doi:10.2514/3.48534

Cited by 36 publications

(20 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 3, the mean squared velocities of the base plates (V 2 1 ) for the three specimens were coincident below 3000 Hz, which indicates that the decoupling layer provides negligible vibration suppression for the composite coating in that frequency range. However, above 3000 Hz, the value of V 2 1 for DC-002 decreased due to the enhanced reaction force caused by the increased radiation sound power at high frequencies. Figure 4 compares V 2 1 and V 2 2 for the three specimens, where the difference V 2 1 − V 2 2 reflects the degree of decoupling and vibration isolation efficiency of the decoupling layer, which increases with positively increasing…”

Section: Vibroacoustic Response With Different Composite Specimensmentioning

confidence: 96%

“…In this paper, three vibroacoustic indicators are introduced: the mean squared velocity of the base plate (V 2 1 ), the mean squared velocity of the outer surface of the decoupling layer (V 2 2 ), and the radiated sound power by the system in water ( ). The definitions of the vibroacoustic indicators have been previously published [14,15,17].…”

Section: Dynamics Of the System As Shown Inmentioning

confidence: 99%

“…Numerous studies have been performed regarding the vibroacoustics of resonant structures covered by damping coatings. Alam and Asnani [1,2] employed variational principles to derive the governing equation of a cylindrical shell covered by a multilayered damping coating. Laulagnet and Guyader [3][4][5] researched the vibroacoustic response of a finite cylindrical shell covered by a damping coating based on Donnell and Flügge thin shell theory.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental and Theoretical Analysis for a Fluid-Loaded, Simply Supported Plate Covered by a Damping and Decoupling Composite Acoustic Coating

Yuan

Meng

Liu

et al. 2017

Shock and Vibration

View full text Add to dashboard Cite

This work presents a vibroacoustic response model for a fluid-loaded, simply supported rectangular plate covered by a composite acoustic coating consisting of damping and decoupling layers. The model treated the damping layer and base plate as a unified whole under pure bending moments and the decoupling layer as a three-dimensional, isotropic, linear elastic solid. The validity of the model was verified by both numerical analysis and experiments and was shown to accurately extend previous studies that were limited to a plate covered by a single damping or decoupling layer with an evaluation confined solely to numerical analysis. The trends of the numerical and experimental results are generally consistent, with some differences due to the influences of water pressure and the frequency dependence of the material parameters, which are not taken into account by the numerical analysis. Both experimental and numerical results consistently show that the radiated noise reduction effect of the composite coating is superior to that of single-type coatings, which is attributed to the fact that the composite coating combines the merits of both the high vibration suppression performance of the damping layer and the superior vibration isolation performance of the decoupling layer.

show abstract

Section: Vibroacoustic Response With Different Composite Specimensmentioning

confidence: 96%

Section: Dynamics Of the System As Shown Inmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental and Theoretical Analysis for a Fluid-Loaded, Simply Supported Plate Covered by a Damping and Decoupling Composite Acoustic Coating

Yuan

Meng

Liu

et al. 2017

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…To satisfy the boundary conditions, it is required that det( = ( [2,3,6,7,10,11,13,16], [1,4,5,8,9,12,14,15])) = 0. The natural frequency and loss factor can be obtained by solving the equations, and varies with different boundary conditions.…”

Section: Solutions Of the Equationsmentioning

confidence: 99%

“…Pan [7] studied the axisymmetrical vibration of a finite length cylindrical shell with a viscoelastic core. Alam and Asnani [8,9] considered the vibration and damping analysis of a general multilayered cylindrical shell having an arbitrary number of orthotropic material layers and viscoelastic layers.…”

Section: Introductionmentioning

confidence: 99%

Vibration and Damping Analysis of a Multilayered Composite Plate with a Viscoelastic Midlayer

Wan

Zheng

2016

Shock and Vibration

View full text Add to dashboard Cite

Based on the theory of Donnell and Kirchhoff hypothesis and by using the complex constant model of viscoelastic materials, the vibration equations of five-layered constrained damping plate are established. The transfer matrix method (TMM) is improved and used to solve equations. The improved TMM is more effective to solve complex structural vibration. The influence of layer numbers, thickness of each layer, and arrangement of materials on vibration behavior are discussed. It is proved that multilayered plates can more effectively reduce natural frequency and obtain higher structural loss factor. The loss factor increases with the number of whole layers. Symmetrical structure can obtain higher structural loss factor than one-direction structure. Uniform arrangement of viscoelastic materials and constrained materials can obtain higher structural loss factor than nonuniform arrangement. There is different optimum frequency with different material thickness, and the optimum frequency is not dependent from layer numbers.

show abstract

Vibration and Damping of Composite Structures

Paonessa

2012

Wiley Encyclopedia of Composites

View full text Add to dashboard Cite

Today the composite materials are more and more used to provide structure for several industrial applications. The aeronautic industry is coming the last in this material user community, but recently the use in aeronautic is increasing, in fact if in the past the composite (mainly, carbon fiber based) have been used for non critical structure components, like small doors or firings, today the use has been applied to wing and tail components, recently the use has been enlarged to the main fuselage structure. One of the important design requirements of this new structure is to comply with the very demanding constraints related to the vibration and correlated sound generation. There are many applications in which the vibration response of structures is important. These include, among others, noise and vibration control techniques applied to different structures: small, as an example, a tennis rackets or very large as an aircraft. In these examples, the dynamic properties of structures can contribute to excessive vibration, which produces high noise levels, fatigue failure, premature wear, operator discomfort, and unsafe operating conditions. Laminated composites can be effective in eliminating vibration and sound. This is a recent technological development, and this article provides an introduction and hopefully stirs the interest of engineers and other product development people. The process by which a polymer converts vibration energy to heat is known as damping . The process by which a polymer, or anything else, is moistened by water is known as dampening . This article deals with the first of these terms. After reviewing the basic concepts and definitions of vibration, this article discusses methods of vibration analysis, which include macromechanical and micromechanical modeling. This is followed by an introduction to the experimental determination of composite vibration response. The effects of material variables and structural parameters on the composite vibration are discussed in a subsequent section. Finally, a section is devoted to a review of the application of vibration techniques and concepts to noise control, composite design, and nondestructive evaluation (NDE).

show abstract

Vibration and Damping Analysis of a Multilayered Cylindrical Shell, Part 11: Numerical Results

Cited by 36 publications

References 1 publication

Experimental and Theoretical Analysis for a Fluid-Loaded, Simply Supported Plate Covered by a Damping and Decoupling Composite Acoustic Coating

Experimental and Theoretical Analysis for a Fluid-Loaded, Simply Supported Plate Covered by a Damping and Decoupling Composite Acoustic Coating

Vibration and Damping Analysis of a Multilayered Composite Plate with a Viscoelastic Midlayer

Vibration and Damping of Composite Structures

Contact Info

Product

Resources

About