Analysis of Structure–Acoustic Coupling Characteristics Between Adjacent Flexible Panels and Enclosed Cavity

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Jie Zhang ◽  
Jian Pang ◽  
Yuping Wan ◽  
Liang Yang ◽  
Wenyu Jia ◽  
...  
Keyword(s):  
Coupling Effect ◽  
Structural Characteristics ◽  
Coupled System ◽  
Coupling Mechanism ◽  
Coupling Coefficients ◽  
Mathematical Methods ◽  
Modal Expansion ◽  
Acoustic Coupling ◽  
Coupling Characteristics ◽  
Flexible Panels

Abstract This article studies the structure–acoustic coupling mechanism between two adjacent flexible panels and an enclosed cavity by analytical and mathematical methods based on modal expansion methods and impedance mobility techniques. The results show that the coupling relations among subsystem modes of the coupled system have selectivity characteristics. The coupling strength depends on the normalized mode–shape coupling coefficients. The coupling relationship between two flexible panels is established through the enclosed cavity. The structural–acoustic coupling effect mainly affects the low-order modes of the coupled system, especially the first-order modes of the panels and cavity. When one panel is weakly coupled with the cavity, the two flexible panels are decoupled. The vibration of the panel only depends on its structural characteristics and external excitation, and the panel radiates sound into the cavity. The vibration of another panel depends not only on its structural characteristics but also on its coupling effect with the cavity.

Structural-Acoustic Coupling Analysis of Two Cavities Connected by Boundary Structures and Small Holes

2005 ◽  
Vol 127 (6) ◽  
pp. 566-574 ◽  
Author(s):  
Chang-Gi Ahn ◽  
Hyoung Gil Choi ◽  
Jang Moo Lee
Keyword(s):  
Low Frequency ◽  
Coupled System ◽  
Expansion Method ◽  
Mode Shapes ◽  
Coupling Analysis ◽  
Theoretical Formulation ◽  
Modal Expansion ◽  
Acoustic Coupling ◽  
Coupling Characteristics ◽  
Small Holes

In some passenger vehicles, unexpected acoustic modes in the low-frequency range may be observed that cannot be explained by the conventional vibro-acoustic coupling analysis. It is because these methods only use the dynamic characteristics of a vehicle structure and its compartment cavity. However, some small holes or gaps existing at the boundaries between the compartment cavity and the trunk cavity of the vehicles change the modal characteristics of a coupled system. In this paper, a new analytical method is presented to investigate the structural-acoustic coupling characteristics of two cavities connected by small holes and in-between boundary structures. Small holes are modeled as an equivalent mass-spring-damper system in the analysis. A theoretical formulation for vibro-acoustic characteristics of this system is made, and the modal expansion method is used to obtain eigenvalues and their mode shapes. The validity of the proposed method is successfully examined by comparing the results of the analytical predictions with those of experiments.

Vibration Localization in a Fluid-Loaded Rectangular Plate with Rib Irregularity

2012 ◽  
Vol 226-228 ◽  
pp. 191-194
Author(s):  
Hao Hao Hu ◽  
De Jiang Shang
Keyword(s):  
Coupling Effect ◽  
Coupled System ◽  
Expansion Method ◽  
Heavy Fluid ◽  
Range Interaction ◽  
Modal Expansion ◽  
Vibration Localization ◽  
Modal Expansion Method ◽  
Force Coupling ◽  
Long Range Interaction

This paper studies the vibration localization of fluid-loaded irregularly ribbed plate analytically. The modal expansion method was adopted to solve the multi-coupled system, the ribs were considered as Timoshenko beams attached to the plate. The localization mechanism was investigated by comparing different coupling effect at the plate-beam interface, it was found the ribs space irregularity only localize the modes associated with the shear force coupling. Both the light and heavy fluid loading pressure were concerned by Rayleigh integral , the study showed that obvious vibration localization phenomenon can be achieved by the ribs space irregularity, and the localization effect was weakened by the long range interaction through the heavy fluid, although the response amplitude of the modes decreased obviously. The investigation may be quite significant for vibration confinement and noise control in engineering.

Modal Analysis of Fluid-Structure Interaction in a Bent Pipeline

2016 ◽  
Author(s):  
Gudrun Mikota ◽  
Rainer Haas ◽  
Evgeny Lukachev
Keyword(s):  
Modal Analysis ◽  
Degrees Of Freedom ◽  
Coupling Effect ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Coupling Mechanism ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Resonance Coupling ◽  
Measured Frequency Response

Fluid-structure interaction in a bent pipeline is investigated by modal methods. Measured frequency response functions between flow rate excitation and pressure response indicate a coupling effect near the third pipeline resonance. Using modal coordinates for the hydraulic and the mechanical subsystems, a two-degrees-of-freedom study of resonance coupling is carried out. An experimental modal analysis of the coupled hydraulic-mechanical system confirms the predicted resonance splitting; it illustrates the coupling mechanism and shows the relevant mechanical part. An analytical fluid-structure interaction model succeeds in reproducing the measured coupling effect. This model is also used for modification prediction; it demonstrates that an appropriate assembly of mass and damping on the pipeline can help to reduce hydraulic resonance amplitudes.

Control of the Flight Vehicle Cable over Wide Spectrum Radiation Effects Simulation Experiment Research

2012 ◽  
Vol 510 ◽  
pp. 141-146
Author(s):  
Yi Lv
Keyword(s):  
Radiation Effects ◽  
Coupling Effect ◽  
Wide Spectrum ◽  
Ultra Wideband ◽  
Vehicle Body ◽  
Coupling Mechanism ◽  
High Power Microwave ◽  
Control Order ◽  
And Control ◽  
Environment Performance

According to the aircraft is under complex work hard to electromagnetic environment performance analysis of the issue, a vehicle body and control lead in ultra-wideband high power microwave (UWS-HPM) under the irradiation of coupling effect and experimental study. Use back to lose signal simulator with the repetitive; the change control the length of the wire, radiation orientation, irradiation parts and other measures to make the experiment generality. The results of the study show that: aircraft in more than 25 kV/m of field UWS-HPM irradiation, interference and make its crash. Interference coupling mechanism is energy electromagnetic pulse through the control lead into the control box, and influence the formation of the control order. On the basis of experiment, this paper analyzes the interference with various factors coupling relation, which for electromagnetic protection equipment provides a theoretical basis.

Dynamic Properties of Coupled Train-Bridge Interaction System

2014 ◽  
Vol 1065-1069 ◽  
pp. 875-881
Author(s):  
Xue Tong Si ◽  
Ke Jian Chen ◽  
Wen Hua Guo
Keyword(s):  
Finite Element ◽  
Coupling Effect ◽  
Dynamic Properties ◽  
Coupled System ◽  
Dynamic Responses ◽  
Plate Model ◽  
Lateral Direction ◽  
Long Span ◽  
Interaction System ◽  
Spatial Beam

This paper investigates the dynamic properties of each sub-system of a coupled railway train-bridge interaction system. Both spatial beam-plate model and spatial grillage model are built for a long-span dual-deck cable-stayed railway bridge by use of finite element method. The railway train is modeled as a mass-spring-damper system. Then free vibration equations are established based on the finite element models and then subspace iteration method is employed to calculate the dynamic properties for each sub-system. Results show that the spatial grillage model agrees well with the spatial beam-plate model in terms of mass and stiffness distribution. The spatial beam-plate model serves as benchmark solution and the grillage model as a tool for dynamic responses of the coupled system due to its computational efficiency. It also shows that first modes of both the railway train and long-span bridge are lateral direction, which indicates that the train may experience much response in lateral direction. Therefore attention should be drawn to the lateral running stability and safety of railway train due to the coupling effect between the bridge and railway train.

scholarly journals When two wrongs make a right: synchronized neuronal bursting from combined electrical and inhibitory coupling

2017 ◽  
Vol 375 (2096) ◽  
pp. 20160282 ◽  
Author(s):  
Reimbay Reimbayev ◽  
Kevin Daley ◽  
Igor Belykh
Keyword(s):  
Electrical Coupling ◽  
Coupled System ◽  
Underlying Mechanism ◽  
Mathematical Methods ◽  
Synaptic Inputs ◽  
Bursting Neurons ◽  
Robust Synchronization ◽  
Neuronal Mechanisms ◽  
Central Nervous Systems ◽  
Inhibitory Coupling

Synchronized cortical activities in the central nervous systems of mammals are crucial for sensory perception, coordination and locomotory function. The neuronal mechanisms that generate synchronous synaptic inputs in the neocortex are far from being fully understood. In this paper, we study the emergence of synchronization in networks of bursting neurons as a highly non-trivial, combined effect of electrical and inhibitory connections. We report a counterintuitive find that combined electrical and inhibitory coupling can synergistically induce robust synchronization in a range of parameters where electrical coupling alone promotes anti-phase spiking and inhibition induces anti-phase bursting. We reveal the underlying mechanism, which uses a balance between hidden properties of electrical and inhibitory coupling to act together to synchronize neuronal bursting. We show that this balance is controlled by the duty cycle of the self-coupled system which governs the synchronized bursting rhythm. This article is part of the themed issue ‘Mathematical methods in medicine: neuroscience, cardiology and pathology’.

Analysis of the coupling characteristics of a tapered three-guide coupled system

1990 ◽  
Vol 8 (10) ◽  
pp. 1621-1629 ◽  
Author(s):  
Y. Cai ◽  
T. Mizumoto ◽  
Y. Naito
Keyword(s):  
Coupled System ◽  
Coupling Characteristics

scholarly journals A Novel Design of Rescue Capsule considering the Pressure Characteristics and Thermal Dynamic Response with Thermomechanical Coupling Action Subjected to Gas Explosion Load

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaowei Zhai ◽  
Shibo Wu ◽  
Kai Wang ◽  
Xiaokun Chen ◽  
Haitao Li
Keyword(s):  
Dynamic Response ◽  
Coal Mine ◽  
Coupling Effect ◽  
Design Method ◽  
Thermomechanical Coupling ◽  
Structural Safety ◽  
Coupling Mechanism ◽  
Gas Explosion ◽  
Explosion Load ◽  
Mine Rescue

To ensure the structural safety and reliability of coal mine rescue capsule in disastrous surroundings after gas explosion, in this paper, the thermomechanical coupling effect on a certain structure subjected to gas explosion was analyzed, and then a novel rescue capsule with a combination of radius and square features was designed according to the underground surroundings and relevant regulations on mine rescue devices. Foremost, the coupling mechanism of thermal-fluid-solid interaction between gas explosion shock wave and rescue capsule and the thermal dynamic response of the capsule subjected to explosion load of gas/air mixture was investigated and revealed by employing LS-DYNA. The variation laws and characteristics of stress field, displacement field, and temperature field of the capsule were analyzed based on the simulation results. Results show that the structural safety, tightness, and reliability of the capsule meet the requirements of the national safety regulations. The design method presented in this work provides a new thought for design of coal mine rescue capsule.

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