604 Damping Loss Factor Estimation Method of Statistical Energy Analysis Using Power Injection Method

Statistical Energy Analysis (SEA) is a well-known method to analyze the flow of acoustic and vibration energy in a complex structure. The structure is divided into subsystems where the energy in each of the subsystem is assumed to be reverberant. This study investigates the application of SEA model in a 'damped' acoustic space where the direct field component from the sound source dominates the total sound field rather than a diffuse field in a reverberant space which the SEA model assumption is based on. A measurement was conducted in a scaled room divided into two acoustic spaces separated by a partition with an opening. Absorbent materials were installed on the room walls and the power injection technique was implemented to obtain the coupling loss factor (CLF) of the system. It is found that correction of the direct field component from the subsystem energy improves the prediction of the CLF of the system.

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Prediction of Transient Vibration Envelopes Using Statistical Energy Analysis Techniques

Journal of Vibration and Acoustics ◽

10.1115/1.2930088 ◽

1990 ◽

Vol 112 (1) ◽

pp. 127-137 ◽

Cited By ~ 23

Author(s):

M. L. Lai ◽

A. Soom

Keyword(s):

Loss Factor ◽

Energy Analysis ◽

A Priori ◽

Coupled Systems ◽

Time Varying ◽

Statistical Energy Analysis ◽

Coupling Loss ◽

Transient Vibration ◽

Coupled Plates ◽

Coupling Loss Factor

The prediction, by the statistical energy analysis (SEA) method, of transient vibration envelopes for coupled systems is investigated. The relation between the time-varying energy transferred between two coupled subsystems and time-varying energies of the subsystems is studied numerically and experimentally. These studies indicate that time-varying energy transmitted between two subsystems is related to the subsystem energies by an apparent time-varying coupling loss factor. It is shown that the apparent coupling loss factor approaches the asymptotic (or steady-state) coupling loss factor as response energies and transferred energies are integrated over progressively larger times. Both the apparent time-varying coupling loss factor and the asymptotic coupling loss factor, determined experimentally, are used in energy balance equations to predict the time-varying vibration envelopes of a system of two point-coupled plates and the results are compared. Although overall response predictions are similar, considerable differences are noted in individual frequency bands. However, no general method for a priori determination of the apparent time-varying coupling loss factor is suggested.

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Panel Damping Loss Factor Estimation Using the Random Decrement Technique

51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference<BR> 18th AIAA/ASME/AHS Adaptive Structures Conference<BR> 12th ◽

10.2514/6.2010-3113 ◽

2010 ◽

Author(s):

Mark Ewing ◽

Himanshu Dande

Keyword(s):

Loss Factor ◽

Random Decrement Technique ◽

Random Decrement ◽

Damping Loss Factor ◽

Factor Estimation

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On the Coupling Loss Factor in Statistical Energy Analysis

The Journal of the Acoustical Society of America ◽

10.1121/1.1912337 ◽

1971 ◽

Vol 49 (1B) ◽

pp. 352-356 ◽

Cited By ~ 18

Author(s):

Stephen H. Crandall ◽

Robert Lotz

Keyword(s):

Loss Factor ◽

Energy Analysis ◽

Statistical Energy Analysis ◽

Coupling Loss ◽

Coupling Loss Factor

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Application of Statistical Energy Analysis for Damage Detection in Spacecraft Structures

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.293-294.525 ◽

2005 ◽

Vol 293-294 ◽

pp. 525-532 ◽

Cited By ~ 2

Author(s):

J. López-Díez ◽

M. Torrealba ◽

A. Güemes ◽

C. Cuerno-Rejado

Keyword(s):

Damage Detection ◽

Loss Factor ◽

Energy Analysis ◽

Stiffened Panel ◽

Statistical Energy Analysis ◽

Coupling Loss ◽

System Characteristics ◽

Coupling Loss Factor

This paper analyses the applicability of the Statistical Energy Analysis (SEA) for detecting incipient damages in a typical spacecraft structure, as a stiffened panel. The damage on attachment element is investigated by analyzing its influence on the system characteristics. Because of incipient damage affects mainly on highest modes, rather than on lowest, the coupling loss factor between sub-elements can be used to detect and localize the damage.

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