The Vibration Response Analysis of Coupling System and its Experimental Validation Based on the SEA Method

2012 ◽  
Vol 479-481 ◽  
pp. 1314-1317
Author(s):  
Shou Wei Lu ◽  
Hui Hua Feng ◽  
Xiao Long Mou ◽  
Zheng Xing Zuo
Keyword(s):  
Loss Factor ◽  
Coupled System ◽  
Vibration Response ◽  
Response Analysis ◽  
Coupling Loss ◽  
Coupling System ◽  
Internal Loss ◽  
Coupled Plates ◽  
Coupling Loss Factor ◽  
Loss Factors

In this paper, methods of acquiring internal loss factors and coupling loss factors by experimental measurement are investigated. The internal loss factor and coupling loss factor of two coupled plates is measured by the modified power injection method. The SEA model of coupled system is established based on the measured results of internal loss factor (ILF) and coupling loss factor (CLF). A random vibration analysis is conducted as a validation example. Since the formulation solution and measured result agree preferably, the validity of the measurement method and the effectiveness of analyzing vibration response using SEA are proved.

Estimation of coupling loss factors for rectangular plates with different materials and junctions

2019 ◽  
Vol 50 (9-11) ◽  
pp. 306-312
Author(s):  
Mandale Maruti Bhagwan ◽  
Bangarubabu Popuri
Keyword(s):  
Loss Factor ◽  
Energy Analysis ◽  
Acoustic Analysis ◽  
Composite Plates ◽  
Rectangular Plates ◽  
Coupling Loss ◽  
Tightening Torque ◽  
Essential Parameter ◽  
Coupling Loss Factor ◽  
Loss Factors

In statistical energy analysis, coupling loss factor is the essential parameter for vibro-acoustic analysis of complicated structures. The coupling loss factors have been estimated using energy-level difference method. The tightening torque applied at structural junction has been varied. Higher values of coupling loss factor have been observed for higher tightening torque on bolted junction. The coupling loss factors have been determined for various structural junctions of rectangular composite plates. The riveted and bolted junctions have been examined for composite plates in same plane and size. The coupling loss factors for bolted junction are relatively higher than that for riveted junction of composite plates. The values of coupling loss factors are found to increase with increasing tightening torque applied at structural junctions of composite plates. It is also noted that the experimental results of coupling loss factors for point junctions vary with changes in fiber orientations of composite plates. It is firmly believed that the various findings of the coupling loss factors in this article help for vibro-acoustic analysis of complicated structures.

Variability of the coupling loss factor between two coupled plates

2005 ◽  
Vol 279 (3-5) ◽  
pp. 557-579 ◽  
Author(s):  
W.S. Park ◽  
D.J. Thompson ◽  
N.S. Ferguson
Keyword(s):  
Loss Factor ◽  
Coupling Loss ◽  
Coupled Plates ◽  
Coupling Loss Factor

Prediction of Transient Vibration Envelopes Using Statistical Energy Analysis Techniques

1990 ◽  
Vol 112 (1) ◽  
pp. 127-137 ◽  
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.

Statistical energy analysis parameter estimation for different structural junctions of rectangular plates

2016 ◽  
Vol 230 (15) ◽  
pp. 2603-2610 ◽  
Author(s):  
Maruti B Mandale ◽  
P Bangaru Babu ◽  
SM Sawant
Keyword(s):  
Loss Factor ◽  
Energy Analysis ◽  
Rectangular Plates ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Drawing Board ◽  
Board Stage ◽  
Good Agreement ◽  
Coupling Loss Factor ◽  
Loss Factors

In industries, the use of appropriate junctions between components is of paramount interest. Coupling loss factor is one of the important parameters in statistical energy analysis for vibroacoustic analysis of complicated structures in drawing board stage. The values of coupling loss factor were calculated and compared for different junctions. The screwed and bolted junctions were examined for thin rectangular plates of same size. The energy level difference method was used to find coupling loss factors because of its simplicity. These experimentally found coupling loss factors were later compared with analytical solutions. It is noticed that the analytical results are in good agreement with experimental results. It is also observed that coupling loss factor for bolted junction are relatively high than that for screwed junction.

Coupling Loss Factors and Coupling Damping for Flanged Cylindrical Shells

1991 ◽  
Author(s):  
P. R. Keswick ◽  
M. P. Norton
Keyword(s):  
Loss Factor ◽  
Cylindrical Shells ◽  
Coupled Systems ◽  
Flange Joint ◽  
Coupling Loss ◽  
Theoretical Evaluation ◽  
Injection Method ◽  
Power Injection ◽  
Coupling Loss Factor ◽  
Loss Factors

Abstract This paper reports on an investigation into an experimental and theoretical evaluation of coupling loss factors and the experimental evaluation of coupling damping for statistical energy analysis of flanged cylindrical shells. It includes the following. 1. An evaluation of the power injection method and the steady state energy method for determining the coupling loss factors of conservative and non-conservatively coupled cylindrical shells. The investigation also establishes if it is necessary to use post processing or additional damping to the subsystems to obtain meaningful loss and coupling loss factors from the power injection method. 2. Establishment of a procedure for measuring coupling damping using the in-situ loss factors measured from the power injection method for non-conservatively coupled systems. The coupling damping estimates are measured for the same non-conservatively coupled cylindrical shell as used for the coupling loss factor experiments. 3. Usage of an elastic wave propagation analysis to obtain theoretical estimates of the coupling loss factors for cylindrical shells connected by a solid flange joint using the Fliigge stress equations for cylindrical shells. The flange joint arrangement is modelled as a ring connecting the two shell halves, where the Love equations are used to develop the in-plane and out-of-plane ring forces and moment. The coupling loss factor is calculated from the power transmitted across the joint and from the stored energy on the incident side.

scholarly journals IMPROVED ENERGY RATIO METHOD TO ESTIMATE COUPLING LOSS FACTORS FOR SERIES COUPLED STRUCTURE

2015 ◽  
Vol 45 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Jintao Gu ◽  
Meiping Sheng
Keyword(s):  
Coupled System ◽  
Great Accuracy ◽  
Two Dimensions ◽  
Large Dimension ◽  
Energy Ratio ◽  
Ratio Method ◽  
Coupling Loss ◽  
Loss Factors

Energy ratio method (ERM), which is a widely used method for coupling loss factors (CLFs) measurement, may lead to numerical problems because of the inversion of a large dimension matrix. The improved energy ratio method proposed here simplified a series several-coupled system into a two-coupled system so that it becomes a two dimensions matrix instead of large dimensions one. Coupling loss factors of a series three-coupled structure are measured using this method. Vibrating responses of the structure has been tested and predicted with loss and coupling loss factors measured here in order to verify the accuracy of measured CLFs. The agreement of vibrating responses indicates the fact that the improved energy ratio method is of great accuracy and reliability.

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