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The influence of reflections from the train body and the ground on the sound radiation from a railway rail
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作者 David J.Thompson Dong Zhao +3 位作者 Evangelos Ntotsios Giacomo Squicciarini Ester Cierco Erwin Jansen 《Railway Sciences》 2024年第1期1-17,共17页
Purpose – The vibration of the rails is a significant source of railway rolling noise, often forming the dominantcomponent of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper ... Purpose – The vibration of the rails is a significant source of railway rolling noise, often forming the dominantcomponent of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper is toinvestigate the influence of the ground profile and the presence of the train body on the sound radiation fromthe rail.Design/methodology/approach – Two-dimensional boundary element calculations are used, in which therail vibration is the source. The ground profile and various different shapes of train body are introduced in themodel, and results are observed in terms of sound power and sound pressure. Comparisons are also made withvibro-acoustic measurements performed with and without a train present.Findings – The sound radiated by the rail in the absence of the train body is strongly attenuated by shieldingdue to the ballast shoulder. When the train body is present, the sound from the vertical rail motion is reflectedback down toward the track where it is partly absorbed by the ballast. Nevertheless, the sound pressure at thetrackside is increased by typically 0–5 dB. For the lateral vibration of the rail, the effects are much smaller. Oncethe sound power is known, the sound pressure with the train present can be approximated reasonably well withsimple line source directivities.Originality/value – Numerical models used to predict the sound radiation from railway rails have generallyneglected the influence of the ground profile and reflections from the underside of the train body on the soundpower and directivity of the rail. These effects are studied in a systematic way including comparisons with measurements. 展开更多
关键词 Rolling noise sound radiation Railway track Boundary elements Ground reflections DIRECTIVITY
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Vibration and Sound Radiation of Cylindrical Shell Covered with a Skin Made of Micro Floating Raft Arrays Excited by Turbulence 被引量:1
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作者 Dan Zhao Qiong Wu +5 位作者 Minyao Gan Ke Li Wenhong Ma Qun Wu Liqiang Dong Shaogang Liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期2041-2055,共15页
To reduce the vibration and sound radiation of underwater cylindrical shells,a skin composed of micro floating raft arrays and a compliant wall is proposed in this paper.A vibroacoustic coupling model of a finite cyli... To reduce the vibration and sound radiation of underwater cylindrical shells,a skin composed of micro floating raft arrays and a compliant wall is proposed in this paper.A vibroacoustic coupling model of a finite cylindrical shell covered with this skin for the case of turbulence excitation is established based on the shell theories of Donnell.The model is solved with the modal superposition method to investigate the effects of the structural parameters of micro floating raft elements on the performance of reducing vibration and sound radiation of the cylindrical shell of this skin.The results indicate that increasing the stiffness ratio,damping ratio,mass ratio,or decreasing the interval betweenmicro floating raft elements can improve the vibration and sound radiation reduction performance of this skin over the frequency range 0∼2000 Hz.Moreover,the mean quadratic velocity level and sound radiation power level of the finite cylindrical shell with this skin can be reduced by 12.00 dB and 9.65 dB respectively compared to the finite cylindrical shell with homogeneous viscoelastic coating in the frequency range from0∼2000Hz,implying a favorable performance of this skin for reducing the vibration and sound radiation of cylindrical shells. 展开更多
关键词 Finite cylindrical shell vibration and sound radiation noise reduction turbulent pulsating pressure micro floating raft
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Effect of Wheel Load on Wheel Vibration and Sound Radiation 被引量:4
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作者 HAN Jian WANG Ruiqian +4 位作者 WANG Di GUAN Qinghua ZHANG Yumei XIAO Xinbiao JIN Xuesong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第1期46-54,共9页
The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty... The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation, The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t. the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the cffcct of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research. 展开更多
关键词 wheel load vibration and sound radiation finite element method (FEM) boundary element method (BEM) laboratory test field test
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ANALYSIS OF SOUND RADIATION FROM THE RING-STIFFENED CYLINDRICAL SHELL COATED WITH VISCOELASTIC LAYER IN FLUID MEDIUM 被引量:2
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作者 Luo Dongping Cai Minbo Peng Xu Luo Bin (Department of Naval and Ocean Engineering,Huazhong University of Science and Technology,Wuhan 430074,China) 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第2期155-161,共7页
The Donnell theory of shell is applied to describe shell motion and layer motion is described by means of three-dimensional Navier equations.Using deformation harmonious condi- tions of the interface,the effects of st... The Donnell theory of shell is applied to describe shell motion and layer motion is described by means of three-dimensional Navier equations.Using deformation harmonious condi- tions of the interface,the effects of stiffeners and layer are treated as reverse forces and moments acting on the cylindrical shell.In studying the acoustic field produced by vibration of the sub- merged ring-stiffened cylindrical coated shell,the structure dynamic equation,Helmholtz equation in the fluid field and the continuous conditions of the fluid-structure interface compose the cou- pling vibration equation of the sound-fluid-structure.The extract of sound pressure comes down to the extract of coupling vibration equation.By use of the solution of the equation,the influ- ences of hydrostatic pressure,physical characters and geometric parameters of the layer on sound radiation are discussed. 展开更多
关键词 viscoelastic layer ring-stiffened cylindrical coated shell coupling vibration equation sound radiation
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NUMERICAL SIMULATION OF SOUND RADIATION ON GEARBOX'S HOUSING 被引量:1
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作者 XIANG Changle WANG Wenping LIU Hui 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第3期26-30,共5页
The fluid-structure coupling finite element model and the boundary element model of a complex gearbox's housing are built based on the theory of fluid-structure coupling finite element method and boundary element met... The fluid-structure coupling finite element model and the boundary element model of a complex gearbox's housing are built based on the theory of fluid-structure coupling finite element method and boundary element method. At the same time, the exciting forces of the housing are analyzed and applied to the finite element models. Firstly, vibration of the housing is calculated by the fluid-structure coupling finite element model; secondly, the calculated result is verified by the experiment; finally, sound radiation of the housing is calculated by the boundary element. According to the calculated results, the housing adds some ribs not only to increase the strength, but also to reduce the sound radiation of the housing. At last, the sound radiation of the modified housing is calculated, which shows that the sound radiation of the modified housing with ribs is lower. 展开更多
关键词 sound radiation Finite element model Boundary element model Fluid-structure coupling
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Acoustic design sensitivity analysis of structural sound radiation 被引量:1
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作者 许智生 《Journal of Chongqing University》 CAS 2009年第4期250-256,共7页
This paper presents an acoustic design sensitivity(ADS)analysis on sound radiation of structures by using the boundary element method(BEM).We calculated the velocity distribution of the thin plate by analytical method... This paper presents an acoustic design sensitivity(ADS)analysis on sound radiation of structures by using the boundary element method(BEM).We calculated the velocity distribution of the thin plate by analytical method and the surface sound pressure by Rayleigh integral,and expressed the sound radiation power of the structure in a positive definite quadratic form of the Hermitian with an impedance matrix.The ADS analysis of the plate was thus translated into the analysis of structure dynamic sensitivity and ... 展开更多
关键词 acoustic design sensitivity analysis sound radiation impedance matrix Rayleigh integral
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Sound radiation of a functionally graded material cylindrical shell in water by mobility method 被引量:1
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作者 Buqing Xu,1,2, ) Shaopu Yang,3, and Haoyu Li1, 1)Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 050043, China 2)Provincial Laboratory of Traffic Safety and Control of Hebei, Shijiazhuang Tiedao University, Shijiazhuang 050043, China 3)Shijiazhuang Tiedao University, Shijiazhuang 050043, China 《Theoretical & Applied Mechanics Letters》 CAS 2011年第6期69-74,共6页
Based on the fundamental dynamic equations of functionally graded material (FGM) cylindrical shell, this paper investigates the sound radiation of vibrational FGM shell in water by mobility method. This model takes in... Based on the fundamental dynamic equations of functionally graded material (FGM) cylindrical shell, this paper investigates the sound radiation of vibrational FGM shell in water by mobility method. This model takes into account the exterior fluid loading due to the sound press radiated by the FGM shell. The FGM cylindrical shell was excited by a harmonic line radial force uniformly distributing along the generator. The FGM shell equations of motion, the Helmholtz equation in the exterior fluid medium and the continuity equation at fluid-shell interface are used in this vibroacoustic problem. The expressions of sound radiation efficiency and sound field of the FGM shell have been derived by mobility method. Radiation efficiency, modal mobility and the directivity pattern of the sound field are solved numerically. In particular, radiation efficiency and directivity pattern with various power law index are analyzed. 展开更多
关键词 fluid-loaded cylindrical shell functionally graded material mobility method sound radiation
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Active Control of Structurally Radiated Sound from an Elastic Cylindrical Shell 被引量:2
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作者 靳国永 刘小玲 刘志刚 《Journal of Marine Science and Application》 2011年第1期88-97,共10页
A numerical and experimental study was presented on active control of structurally radiated sound from an elastic cylindrical shell.An analytical model was developed for the active structural acoustic control (ASAC) o... A numerical and experimental study was presented on active control of structurally radiated sound from an elastic cylindrical shell.An analytical model was developed for the active structural acoustic control (ASAC) of the cylindrical shell.Both global and local control strategies were considered.The optimal control forces corresponding to each control strategy were obtained by using the linear quadratic optimal control theory.Numerical simulations were performed to examine and analyze the control performance under different control strategies.The results show that global sound attenuation of the cylindrical shell at resonance frequencies can be achieved by using point force as the control input of the ASAC system.Better control performance can be obtained under the control strategy of minimization of the radiated sound power.However,control spillover may occur at off-resonance frequencies with the control strategy of structural kinetic energy minimization in terms of the radiated sound power.Considerable levels of global sound attenuation can also be achieved in the on-resonance cases with the local control strategy,i.e.,minimization of the mean-square velocity of finite discrete locations.An ASAC experiment using an FXLMS algorithm was implemented,agreement was observed between the numerical and experimental results,and successful attenuation of structural vibration and radiated sound was achieved. 展开更多
关键词 cylindrical shell radiated sound power active structural acoustic control (ASAC) FXLMS algorithm
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A General Method to Study the Sound Radiation of a Finite Cylindrical Shell Based on Elastic Theory
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作者 Junjie Zhang Chunhui Yuan +1 位作者 Xianming Zhu Tianyun Li 《Journal of Marine Science and Application》 2012年第2期258-264,共7页
A general method was proposed to study the sound and vibration of a finite cylindrical shell with elastic theory. This method was developed through comprehensive analysis of the uncoupled Helmholtz equation obtained b... A general method was proposed to study the sound and vibration of a finite cylindrical shell with elastic theory. This method was developed through comprehensive analysis of the uncoupled Helmholtz equation obtained by the decomposition of elastic equations and the structure of the solution of a finite cylindrical shell analyzed by thin shell theory. The proposed method is theoretically suitable for arbitrary thickness of the shell and any frequency. Also, the results obtained through the method can be used to determine the range of application of the thin shell theory. Furthermore, the proposed method can deal with the problems limited by the thin shell theory. Additionally, the method can be suitable for several types of complex cylindrical shell such as the ring-stiffened cylindrical shell, damped cylindrical shell, and double cylindrical shell. 展开更多
关键词 finite cylindrical shell elastic theory sound radiation thin shell theory
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Sound Radiation Analysis of Damping Structure Based on Response Surface Method
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作者 梁新华 林忠钦 +1 位作者 朱平 高新华 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第1期29-34,共6页
The methods of modifying dimension and shape of structure, or covering damping material are effective to reduce structure-borne noise, while these methods are based on the knowledge of qualitative and quantitative rel... The methods of modifying dimension and shape of structure, or covering damping material are effective to reduce structure-borne noise, while these methods are based on the knowledge of qualitative and quantitative relationship between sound radiation and design parameters. In order to decrease the complexity of the problem, response surface method(RSM) was utilized to analyze and optimize the vibro-acoustic properties of the damping structure. A simple case was illustrated to demonstrate the capabilities of the developed procedure. A structure-born noise problem was approximated by a series of polynomials using RSM. Three main performances were considered, i.e. sound radiation power, first order modal frequency and total mass. Consequently, the response surface model not only gives the direction of design modification, it also leads to an optimal design of complex systems. 展开更多
关键词 response surface method (RSM) damping structure sound radiation structure-born noise
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A General Model for Analysis of Sound Radiation from Orthogonally Stiffened Laminated Composite Plates
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作者 金叶青 庞福振 +1 位作者 杨飞 李光明 《China Ocean Engineering》 SCIE EI CSCD 2014年第4期457-470,共14页
A general theoretical model is developed to investigate the sound radiation from an infinite orthogonally stiffened plate under point excitation force. The plate can be metallic or composite, and fluid loading is also... A general theoretical model is developed to investigate the sound radiation from an infinite orthogonally stiffened plate under point excitation force. The plate can be metallic or composite, and fluid loading is also considered in the research. The first order shear deformation theory is used to account for the transverse shear deformation. The motion of the equally spaced stiffeners is examined by considering their bending vibrations and torsional movements. Based on the periodic structure theory and the concepts of the equivalent dynamic flexibility of the plate, the generalized vibro-acoustic equation of the model is obtained by applying the Fourier transform method. The generalized model that can be solved numerically is validated by comparing model predictions with the existing results. Numerical calculations are performed to investigate the effects of the location of the excitation, the spacing of the stiffeners, the plate thickness, the strengthening form and the fiber orientation on the sound radiation characteristic of the orthogonaUy stiffened plate, and some practical conclusions are drawn from these parameter studies. 展开更多
关键词 sound radiation orthogonally stiffened plates first order shear deformation theory wavenumber analysis equivalent dynamic flexibility
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Active Control of Sound Transmission in Ship Cabins Through Multiple Independently Supported Flexible Subplates
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作者 Liping Zhu Tiejun Yang +2 位作者 Xinhui Li Lihong Pang Minggang Zhu 《Journal of Marine Science and Application》 CSCD 2020年第1期116-126,共11页
The vibration and noise produced by the powertrain and waves inside ship cabins limit working efficiency and crew and passengers’accommodation quality.This paper simplifies ship cabins as cavities and explores active... The vibration and noise produced by the powertrain and waves inside ship cabins limit working efficiency and crew and passengers’accommodation quality.This paper simplifies ship cabins as cavities and explores active control techniques to attenuate sound transmission via multiple parallel-supported flexible subplates.The theoretical formulations of the interaction between multiple subplates and cavities were performed and the coupling relationships between them were analyzed.Based on the multiple subplates and the cavity coupling models,numerical simulations were performed using the derived optimal controller to minimize the transmission of sound into the cavities through two and nine parallel-supported subplates.The various control strategies were explored to minimize the coupling system’s acoustic potential energy,and the control performances were compared and discussed.The mechanism of reducing sound transmission through multiple supported subplates into a cavity is revealed.The simulation results showed that the vibration pattern of the controlled subplate is changed after it is regulated,which increases its radiation to subdue the other subplates’radiation,while increasing vibration of the controlled subplate.The more subplates a cavity has,the more kinetic energy the controlled subplate possess.Furthermore,the noise reduction performance of a cavity with fewer subplates is better than that with more subplates. 展开更多
关键词 Active structural-acoustic control Cabin noise Multiple subplates sound radiation Structural-acoustic coupling
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Research on vibration and near-field sound radiation of ring-ribbed cylindrical shell coated deadening and decoupling materials
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作者 YAO Xiong-liang LIU Qing-jie YU Xiu-bo 《Journal of Marine Science and Application》 2007年第1期21-30,共10页
The research on structural vibration and sound radiation of underwater ring-ribbed cylindrical shell, which is coated with a kind of deadening and decoupling materials, becomes a focus in recent years. This paper anal... The research on structural vibration and sound radiation of underwater ring-ribbed cylindrical shell, which is coated with a kind of deadening and decoupling materials, becomes a focus in recent years. This paper analyzes the problem on two aspects: model experiment and numerical calculation. The model experiment is carried out including three cases firstly, in which the structural vibration response and radiating acoustic field are measured respectively, and the results gained in these three cases are analyzed to discuss the effect of reducing structural vibration and radiating noise of the deadening and decoupling materials. The coupling FEM/BEM and the SEA methods are both used in numerical calculation, i.e. the arithmetic of the coupling FEM/BEM method is adopted to calculate the low frequency characteristics and the SEA method is adopted to calculate the medium-high frequencies characteristics of the model. By comparing experimental results with numerical calculation results, it is proved that the algorithm adopted in this paper is reasonable. 展开更多
关键词 ring-fibbed cylindrical shell vibration and sound radiation model experiment coupling FEM/BEM method SEA
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ANALYTICAL SOLUTION OF RADIATED SOUND PRESSURE OF RING-STIFFENED CYLINDRICAL SHELLS IN FLUID MEDIUM
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作者 谢官员模 骆东平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第12期1143-1148,共6页
In this paper, analytical formularions of radiated sound pressure of ring-stiffenedcylindrical shells in fluid medium are derived by means of Hamilton's principleHuygens principle and Green function . These formul... In this paper, analytical formularions of radiated sound pressure of ring-stiffenedcylindrical shells in fluid medium are derived by means of Hamilton's principleHuygens principle and Green function . These formulations Can be used to compute the sound pressure of the shell's surface nearfield and farfield. 展开更多
关键词 ring-stiffened cylindrical shell. radiated sound pressure. Huygensprinciple
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THEORETICAL PREDICTION OF SOUND RADIATION FROM A HEAVY FLUID-LOADED CYLINDRICAL COATED SHELL
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作者 Wu, Chengjun Chen, Hualing Huang, Xieqing 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1998年第4期2-9,共8页
A theoretical model is developed to predict the sound radiation ability of a cylindrical thin elastic shell of finite length, covered with a damp layer and terminated with infinite cylindrical rigid baffles. This shel... A theoretical model is developed to predict the sound radiation ability of a cylindrical thin elastic shell of finite length, covered with a damp layer and terminated with infinite cylindrical rigid baffles. This shell is immersed in a heavy fluid extending up to infinity, and excited by a constant point load continuously traveling along the circumferential direction. A frequency-domain representation of the rotating load and three equations of the vibroacoustic coupling problem are given. The equations are solved by means of modal analysis method and asymptotic expansion method. Also, a mathematical expression of modal amplitude of shell radial displacement is obtained. The sound radiation ability of this kind of shell is evaluated and the corresponding numerical results are given. 展开更多
关键词 Rotating load Heavy fluid Cylindrical shell sound radiation
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FORCED VIBRATION AND SOUND RADIATION OF A RECTANGULAR PLATE WITH VISCOELASTIC BOUNDARY SUPPORTS
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作者 Fan Zijie Dept of Automotive Eng.,Qinghua University Kim Kwang Joon Dept of Mechanical Eng.,KAIST,Korea 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1999年第4期276-281,316,共7页
A method for the forced vibration and sound radiation of a rectangular plate with viscoelastic boundary supports is proposed.The method is based on damped complex modes analysis method.Using the damped complex modes o... A method for the forced vibration and sound radiation of a rectangular plate with viscoelastic boundary supports is proposed.The method is based on damped complex modes analysis method.Using the damped complex modes of the plate system,the modal equation of the plate motion becomes completely uncouped.The sound radiation pressure is obtained by numerical integration of the Rayleigh integral.Effects of the viscoelastic boundary supports on the vibration response and the radiated sound pressure of the vibrating plate are discussed by an example. 展开更多
关键词 VIBRATION Viscoelastic damping Supports sound radiation
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Model and optimization of ultrasonic phased array parameters 被引量:1
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作者 钱雪微 王召巴 赵霞 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第2期115-122,共8页
Beam focusing is one of the unique characteristics of ultrasonic phased array compared with conventional ultrasound.On the basis of two-dimensional radiated sound field of phased array,the three-dimensional radiated s... Beam focusing is one of the unique characteristics of ultrasonic phased array compared with conventional ultrasound.On the basis of two-dimensional radiated sound field of phased array,the three-dimensional radiated sound field was simulated in the paper,and then the effect of different frequencies,different number of array elements and different element spacings on focal spot,the depth of focus and the effect on horizontal and vertical resolution were analyzed.The optimal results of transducer parameters have certain reference value for the design of phased array probe. 展开更多
关键词 beam focusing ultrasonic phased array three-dimensional sound field radiation focal spot depth of focus
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Analysis of underwater decoupling properties of a locally resonant acoustic metamaterial coating 被引量:3
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作者 黄凌志 肖勇 +2 位作者 温激鸿 杨海滨 温熙森 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期221-228,共8页
This paper presents a semi-analytical solution for the vibration and sound radiation of a semi-infinite plate covered by a decoupling layer consisting of locally resonant acoustic metamaterial. Formulations are derive... This paper presents a semi-analytical solution for the vibration and sound radiation of a semi-infinite plate covered by a decoupling layer consisting of locally resonant acoustic metamaterial. Formulations are derived based on a combination use of effective medium theory and the theory of elasticity for the decoupling material. Theoretical results show good agree- ments between the method developed in this paper and the conventional finite element method (FEM), but the method of this paper is more efficient than FEM. Numerical results also show that system with acoustic metamaterial decoupling layer exhibits significant noise reduction performance at the local resonance frequency of the acoustic metamaterial, and such performance can be ascribed to the vibration suppression of the base plate. It is demonstrated that the effective density of acoustic metamaterial decoupling layer has a great influence on the mechanical impedance of the system. Furthermore, the resonance frequency of locally resonant structure can be effectively predicted by a simple model, and it can be significantly affected by the material properties of the locally resonant structure. 展开更多
关键词 locally resonant decoupling mechanism underwater sound radiation
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A unified prediction solution for vibro-acoustic analysis of composite laminated elliptical shells immersed in air 被引量:3
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作者 GUAN Xian-lei ZHONG Rui +2 位作者 QIN Bin WANG Qing-shan SHUAI Ci-jun 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期429-444,共16页
A semi-analytical method to conduct vibro-acoustic analysis of a composite laminated elliptical shell immersed in air is proposed.A variational method and multi-segment technique are used to formulate the dynamic mode... A semi-analytical method to conduct vibro-acoustic analysis of a composite laminated elliptical shell immersed in air is proposed.A variational method and multi-segment technique are used to formulate the dynamic model.The sound radiation of the exterior fluid field is calculated by a spectral Kirchhoff–Helmholtz integral formulation.The variables containing displacements and sound pressure are expanded by the combination of Fourier series and Chebyshev orthogonal polynomials.The collocation points are introduced to construct an algebraic system of acoustic integral equations,where these points are distributed on the roots of Chebyshev polynomials,and the non-uniqueness solution of system is eliminated by a combined Helmholtz integral.Numerical examples for sound radiation problems of composite laminated elliptical shells are presented and individual contributions of the circumferential modes to the acoustical results of composite laminated elliptical shells are also given.The effects of geometric and material parameters on sound radiation of composite laminated elliptical shells are also investigated. 展开更多
关键词 composite laminated elliptical shells semi-analytical method VIBRATION sound radiation
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Fluid-structure coupled analysis of underwater cylindrical shells 被引量:1
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作者 艾尚茂 孙丽萍 《Journal of Marine Science and Application》 2008年第2期77-81,共5页
Underwater cylindrical shell structures have been found a wide of application in many engineering fields, such as the element of marine, oil platforms, etc. The coupled vibration analysis is a hot issue for these unde... Underwater cylindrical shell structures have been found a wide of application in many engineering fields, such as the element of marine, oil platforms, etc. The coupled vibration analysis is a hot issue for these underwater structures. The vibration characteristics of underwater structures are influenced not only by hydrodynamic pressure but also by hydrostatic pressure corresponding to different water depths. In this study, an acoustic finite element method was used to evaluate the underwater structures. Taken the hydrostatic pressure into account in terms of initial stress stiffness, an acoustical fluid-structure coupled analysis of underwater cylindrical shells has been made to study the effect of hydrodynamic pressures on natural frequency and sound radiation. By comparing with the frequencies obtained by the acoustic finite element method and by the added mass method based on the Bessel function, the validity of present analysis was checked. Finally, test samples of the sound radiation of stiffened cylindrical shells were acquired by a harmonic acoustic analysis. The results showed that hydrostatic pressure plays an important role in determining a large submerged body motion, and the characteristics of sound radiation change with water depth. Furthermore, the analysis methods and the results are of significant reference value for studies of other complicated submarine structures. 展开更多
关键词 underwater structure fluid-structure coupled analysis initial stress natural frequency sound radiation
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