Testing and Simulation of Mid-High Frequency Acoustics in Vehicle Applying Statiscal Energy Analysis Method

AbstractThe analysis method is developed to obtain dynamic characteristics of the rotating cantilever plate with thermal shock and tip-rub. Based on the variational principle, equations of motion are derived considering the differences between rubbing forces in the width direction of the plate. The transverse deformation is decomposed into quasi-static deformation of the cantilever plate with thermal shock and dynamic deformation of the rubbing plate under thermal shock. Then deformations are obtained through the calculation of modal characteristics of rotating cantilever plate and temperature distribution function. Special attention is paid to the influence of tip-rub and thermal shock on the plate. The results show that tip-rub has the characteristics of multiple frequency vibrations, and high frequency vibrations are significant. On the contrary, thermal shock shows the low frequency vibrations. The thermal shock makes the rubbing plate gradually change into low frequency vibrations. Because rub-induced vibrations are more complicated than those caused by thermal shock, tip-rub is easier to result in the destruction of the blade. The increasing friction coefficient intensifies vibrations of the rubbing plate. Minimizing friction coefficients can be an effective way to reduce rub-induced damage through reducing the surface roughness between the blade tip and the inner surface of the casing.

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Power Flow and Energy Sharing between an Oscillator and a Continuous Receiver Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.1914 ◽

2011 ◽

Vol 189-193 ◽

pp. 1914-1917

Author(s):

Lin Ji

Keyword(s):

High Frequency ◽

Power Flow ◽

Energy Analysis ◽

Statistical Energy Analysis ◽

Coupled Subsystems ◽

Modal Density ◽

Vibration Problems ◽

Energy Sharing ◽

High Modal Density ◽

Vibration Modeling

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.

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Energy Analysis Method Based on Wavelet Transform for Sensor Fault Diagnosis

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.2-3.117 ◽

2011 ◽

Vol 2-3 ◽

pp. 117-122 ◽

Cited By ~ 1

Author(s):

Peng Peng Qian ◽

Jin Guo Liu ◽

Wei Zhang ◽

Ying Zi Wei

Keyword(s):

Wavelet Transform ◽

Fault Diagnosis ◽

Wavelet Analysis ◽

Energy Analysis ◽

Sensor Faults ◽

Analysis Method ◽

Sensor Fault ◽

Fault Type ◽

Ideal Tool ◽

Non Stationary Signal

Wavelet analysis with its unique features is very suitable for analyzing non-stationary signal, and it can also be used as an ideal tool for signal processing in fault diagnosis. The characteristics of the faults and the necessary information on the diagnosis can be constructed and extracted respectively by wavelet analysis. Though wavelet analysis is specialized in characteristics extraction, it can not determine the fault type. So this paper has proposed an energy analysis method based on wavelet transform. Experiment results show the method is very effective for sensor fault diagnosis, because it can not only detect the sensor faults, but also determine the fault type.

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