Acoustic Radiation by Point- or Line-Excited Laminated Plates

2000 ◽  
Vol 122 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Y. F. Hwang ◽  
M. Kim ◽  
P. J. Zoccola
Keyword(s):  
Elasticity Theory ◽  
Sandwich Plate ◽  
Acoustic Radiation ◽  
Single Layer ◽  
Laminated Plates ◽  
Steel Plates ◽  
Numerical Result ◽  
Substantial Error ◽  
Theory Solution ◽  
Equal Thickness

This paper presents an elasticity theory solution for computation of acoustic radiation by a point- or line-excited fluid-loaded laminated plate, which may consist of a stack of an arbitrary number of different isotropic material layers. A one-side water-loaded three-layer sandwich plate, which consists of a hard rubber core sandwiched between two steel plates of equal thickness, was used as an example of the laminated plates. The approximated equivalent sandwich plate solutions were compared with the elasticity theory solutions. These results show that the approximated solutions are, as expected, valid only at frequencies much lower than the coincidence frequency. The numerical result also shows that, even at about one-tenth of the coincidence frequency, the approximated solutions suffer substantial error. The differences between the dry-side- and the wet-side-excited radiated fields of a single-layer uniform plate and a sandwich plate were investigated and compared, and found to be significantly different at frequencies above the coincidence frequency. [S0739-3717(00)01803-1]

Acoustic Radiation by Point- or Line-Excited Laminated Plates

1999 ◽  
Author(s):  
Y. F. Hwang ◽  
M. Kim ◽  
P. J. Zoccola
Keyword(s):  
Elasticity Theory ◽  
Sandwich Plate ◽  
Acoustic Radiation ◽  
Single Layer ◽  
Laminated Plates ◽  
Steel Plates ◽  
Numerical Result ◽  
Substantial Error ◽  
Theory Solution ◽  
Equal Thickness

Abstract This paper presents an elasticity theory solution for computation of acoustic radiation by a point- or line-excited fluid-loaded laminated plate, which may consist of a stack of an arbitrary number of different isotropic material layers. A one-side water-loaded three-layer sandwich plate, which consists of a hard rubber core sandwiched between two steel plates of equal thickness, was used as an example of the laminated plates. The approximated equivalent sandwich plate solutions were compared with the elasticity theory solutions. These results show that the approximated solutions are, as expected, valid only at frequencies much lower than the coincidence frequency. The numerical result also shows that, even at about one-tenth of the coincidence frequency, the approximated solutions suffer substantial error. The differences between the dry-side- and the wet-side-excited radiated fields of a single-layer uniform plate and a sandwich plate were investigated and compared, and found to be significantly different at frequencies above the coincidence frequency.

Refined Multilayered Plate Elements for Coupled Magneto‐Electro‐Elastic Analysis

2009 ◽  
Vol 5 (2) ◽  
pp. 119-138 ◽  
Author(s):  
M. Di Gifico ◽  
P. Nali ◽  
S. Brischetto
Keyword(s):  
Finite Elements ◽  
Kinematic Model ◽  
Single Layer ◽  
Laminated Plates ◽  
Governing Equations ◽  
Elastic Fields ◽  
Plate Elements ◽  
Plate Models ◽  
Multilayered Plates ◽  
Principle Of Virtual Displacements

Finite elements for the analysis of multilayered plates subjected to magneto‐electro‐elastic fields are developed in this work. An accurate description of the various field variables has been provided by employing a variable kinematic model which is based on the Unified Formulation, UF. Displacements, magnetic and electric potential have been chosen as independent unknowns. Equivalent single layer and layer‐wise descriptions have been accounted for. Plate models with linear up to fourth‐order distribution in the thickness direction have been compared. The extension of the principle of virtual displacements to magneto‐electro‐elastic continua has been employed to derive finite elements governing equations. According to UF these equations are presented in terms of fundamental nuclei whose form is not affected by kinematic assumptions. Results show the effectiveness of the proposed elements as well as their capability, by choosing appropriate kinematics, to accurately trace the static response of laminated plates subject to magneto‐electro‐elastic fields.

scholarly journals The Excitation of Ultrasound by Laser Radiation in Water Using an Optical Fiber Laser Converter with a 2D Colloidal Crystalline Coating

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 857
Author(s):  
Vladimir I. Bredikhin ◽  
Viacheslav V. Kazakov
Keyword(s):  
Laser Radiation ◽  
Optical Fiber ◽  
Acoustic Radiation ◽  
Single Layer ◽  
Characteristic Size ◽  
Maximum Temperature ◽  
Quartz Fiber ◽  
Polystyrene Spheres ◽  
Surface Spot ◽  
Sound Pulses

The technology of applying a colloidal single-layer coating of transparent polystyrene (PS) Ø 1 μm spheres at the tip face of a quartz fiber has been proposed and tested. Such a coating plays, in a light absorbing liquid, the role of a converter of pulsed laser radiation into acoustic radiation. The generation of ultrasound in water using a converter based on a quartz fiber 1 mm in diameter with a 2D colloidal crystalline coating consisted of polystyrene spheres with a diameter of ~1 μm at the fiber end was investigated. When excited by laser radiation (λ = 1.064 µm), coating of polystyrene spheres created in the liquid a laser thermal microstructure with a characteristic size of fractions of ~λ and a maximum temperature up to 10−2 degree at an energy in a short laser pulse of ~0.005 J. This short-lived thermal microstructure generated sound pulses in the liquid in the approximately 0.2–4 MHz range. The results of the experimental study of this effect are reported. The proposed laser radiation converter with colloidal coating of the optical fiber distal tip by a single layer of transparent spheres can be used for the development of new laser microtools for studying, processing of various objects in microsurgery, microstructuring of the surface, spot cleaning and restoration of objects of art and history.

Impact Performance Analysis and Optimization of X-Sandwich Panels

2012 ◽  
Vol 204-208 ◽  
pp. 1017-1023
Author(s):  
Lin Wang ◽  
Ai Quan Ye
Keyword(s):  
Sandwich Panel ◽  
Sandwich Plate ◽  
Steel Plates ◽  
Rigid Sphere ◽  
Impact Performance ◽  
Finite Element Software ◽  
Linear Dynamic ◽  
Dynamic Finite Element ◽  
Ordinary Steel ◽  
Better Than

In this paper, ANSYS/LS-DYNA which is a non-linear dynamic finite element software is applied to simulate the processes of two kinds of X-sandwich plate hit by a rigid sphere. Ultimate-ly the sandwich plate can be used to replace some components of the traditional steel protective dev-ices aimed at improving the overall crashworthiness performance of protective devices. This paper analyzes the influence of two plates on crashworthiness. And based on the comparison between the sandwich plates and the equivalent flat plate, the results from numerical simulation show that the X-sandwich panel can provide an excellent crashworthiness.Tight type of X-sandwich board is perfor-ms better than the discrete and ordinary steel plates, which can be applied to bridge protection device.

Cutting Analysis of 3-Layer Laminated Plate

2014 ◽  
Vol 804 ◽  
pp. 307-310
Author(s):  
Key Sun Kim
Keyword(s):  
Cutting Tool ◽  
Cutting Temperature ◽  
Middle Layer ◽  
Work Conditions ◽  
Laminated Plates ◽  
Steel Plates ◽  
Machining Processes ◽  
Layer Structures ◽  
Temperature Strain ◽  
Plane Mode

This paper is a study on cutting analysis of three-layer laminated plates after machining. The outer layers of the milled object were stainless steel and Cr-Mo steel plates, sandwiching a middle layer of aluminum plate. As for the tool, the cylindrical cutter used for groove making was chosen as the model. Analysis was performed in two-dimensional plane mode. As for analysis results, the change in chip shape according to cutting tool travel distance was shown in a series of diagrams, and the cutting temperature, strain rate and required cutting force, etc., were found. It is expected that these results can be utilized in machining processes and work conditions for the machining of multi-layer structures made of layers of different materials.

scholarly journals Prediction and Measurement of the Damping Ratios of Laminated Polymer Composite Plates

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3370
Author(s):  
Hugo Sol ◽  
Hubert Rahier ◽  
Jun Gu
Keyword(s):  
Material Properties ◽  
Single Layer ◽  
Composite Plates ◽  
Laminated Plates ◽  
Secondary Importance ◽  
Reinforced Composite ◽  
Composites Materials ◽  
Modal Damping ◽  
Resonance Frequencies ◽  
Subsequent Step

Laminated composites materials are mostly used in dynamically loaded structures. The design of these structures with finite element packages is focused on vibrations, elastic deformations and failure control. Damping is often neglected because of its assumed secondary importance and also because of dearth of information on relevant material properties. This trend is prone to change as it is now realised that damping plays an increasingly important role in vibration comfort, noise radiation and crash simulations. This paper shows in a first step how to identify the orthotropic elastic and damping properties of single layer fibre-reinforced composite material sheets using a new extended version of the Resonalyser procedure. The procedure is based on the elastic-viscoelastic correspondence principle and uses a mixed numerical experimental method. In a subsequent step, the complex laminate stiffness values are computed using the identified single layer material properties. To validate this approach, the modal damping ratios of arbitrary laminated plates of different materials at several resonance frequencies are predicted and experimentally verified.

Nonlocal elasticity theory for graphene modeling and simulation: prospects and challenges

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
K. M. Liew ◽  
Yang Zhang ◽  
L. W. Zhang
Keyword(s):  
Modeling And Simulation ◽  
Elasticity Theory ◽  
Nonlocal Elasticity ◽  
Single Layer ◽  
Nonlocal Elasticity Theory ◽  
Single Layer Graphene ◽  
Future Research ◽  
Graphene Sheets ◽  
Linear Modeling ◽  
Research Studies

Abstract:This paper presents a literature review of recent research studies on the applications of nonlocal elasticity theory in the modeling and simulation of graphene sheets (GSs). The history, development and excellent properties of GSs are introduced. The details of nonlocal elasticity theory are also presented. A systematic introduction to the application of nonlocal elasticity on linear modeling and nonlinear modeling for single-layer graphene sheets (SLGSs) and multilayered graphene sheets (MLGSs) is also provided. The necessity of determining mechanical parameters and nonlocal parameters is discussed. Recommendations for future work are particularly presented. This work is intended to review the development of GSs, give an introduction to the research studies on nonlocal elasticity theory in the modeling of GSs, and provide recommendations for future research.

Structural and acoustic noise produced by turbulent flow over an elastic trailing edge

1993 ◽  
Vol 442 (1916) ◽  
pp. 533-554 ◽  
Keyword(s):  
Turbulent Flow ◽  
Elastic Plate ◽  
Acoustic Noise ◽  
Acoustic Radiation ◽  
Steel Plates ◽  
Control Surface ◽  
Secondary Source ◽  
Thin Elastic Plate ◽  
Mean Flow ◽  
Trailing Edge

An analysis is made of the sound and vibration produced by turbulent flow at low Mach number over the trailing edge of an elastic plate. The trailing edges of airfoils and other flow control surfaces are known to be important sources of high frequency sound. When the surface is compliant the turbulent edge-flow also excites structural modes of vibration. In conditions of heavy fluid loading, which typically occurs in underwater applications, the energy imparted to the structural motions can be large, and the subsequent scattering of ‘surface waves’ at mechanical discontinuities is frequently an important secondary source of sound. In this paper general formulae are developed for the structural and acoustic edge-noise when the control surface is modelled by a semi-infinite, thin elastic plate which can support bending waves. Numerical results are given for steel plates in air and in water. In the latter case it is shown that, when the frequency is smaller than the coincidence frequency the bending wave power exceeds the total sound power generated at the edge by 20–40 dB, independently of the mean flow velocity, so that sound generated by secondary scattering may then be the dominant source of acoustic radiation.

Sign in / Sign up

Export Citation Format

Share Document