EFFECTIVE INTERNAL LOSS FACTORS AND COUPLING LOSS FACTORS FOR NON-CONSERVATIVELY COUPLED SYSTEMS

1998 ◽  
Vol 209 (4) ◽  
pp. 685-694 ◽  
Author(s):  
M.P. Sheng ◽  
M.Q. Wang ◽  
J.C. Sun
Keyword(s):  
Coupled Systems ◽  
Coupling Loss ◽  
Internal Loss ◽  
Loss Factors

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.

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.

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.

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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