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.

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.

ASYMPTOTIC DECAY TOWARD THE PLANAR RAREFACTION WAVES FOR A MODEL SYSTEM OF THE RADIATING GAS IN TWO DIMENSIONS

2008 ◽  
Vol 18 (04) ◽  
pp. 511-541 ◽  
Author(s):  
WENLIANG GAO ◽  
CHANGJIANG ZHU
Keyword(s):  
Cauchy Problem ◽  
Maximum Principle ◽  
Coupled System ◽  
Model System ◽  
Two Dimensions ◽  
Rarefaction Waves ◽  
Asymptotic Decay ◽  
The Maximum Principle ◽  
The Cauchy Problem ◽  
Asymptotic Decay Rate

In this paper, we consider the asymptotic decay rate towards the planar rarefaction waves to the Cauchy problem for a hyperbolic–elliptic coupled system called as a model system of the radiating gas in two dimensions. The analysis based on the standard L2-energy method, L1-estimate and the monotonicity of profile obtained by the maximum principle.

Measurement of SEA coupling loss factors using point mobilities

1994 ◽  
Vol 346 (1681) ◽  
pp. 465-475 ◽  
Keyword(s):  
Coupled Systems ◽  
Coupling Loss ◽  
Good For ◽  
Loss Factors

In this paper calculation of SEA coupling loss factors, using measured point mobility, is derived for coupled systems, homogeneous or not, with rigid or soft links. Some simplifications and hypothesis are necessary to fit with SEA basic relations. To validate the theory an experiment was done on plates coupled in three points; the agreement is reasonably good for homogeneous and non-homogeneous plates.

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.

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