Computational Evaluation of Damping and Decoupling Materials - Phase III

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Authors
  1. Foin, G.
  2. Berry, A.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN);Sherbrooke Univ, Sherbrooke ONT (CAN) Acoustics and Vibration Group
Abstract
This report presents theoretical models and numerical results of the vibroacoustic behaviour of plane structures covered by damping or decoupling materials and immersed in water. A novel theoretical model that accounts for the three-dimensional theory of elasticity for decoupling coatings is proposed. This model allows all components of stress and strain to be taken into account in the coating layer. The three-dimensional model points out the existence of two types of waves in the coating: longitudinal (or compressional) waves and shear (or transverse) waves. Numerical results show that the shear waves are almost negligible in comparison to the compressional waves, so that a simplified model that neglects shear waves can be derived from the complete 3D model. The 3D model is compared to a previous model developed for DREA, based on the locally reacting assumption (DREA CR/96/427). It is also compared to models proposed in the literature for infinite structures (Ko 1997, House 1991). A complete parametric study of the 3D model allows its interest to be highlighted. A model that accounts for partial constrained damping treatment is also proposed. This model is able to evaluate the vibration and acoustic response of a plate partially covered by a viscoelastic layer and a constraining layer. The influence of the surface of the coverage on the global noise reduction is investigated.
Keywords
Decoupling;Constrained layer damping;Vibro-acoustics;Transverse waves;Compressional waves
Report Number
DREA-CR-2000-016 — Contractor Report
Date of publication
01 Feb 2000
Number of Pages
104
DSTKIM No
CA001547
CANDIS No
513483
Format(s):
Hardcopy;Document Image stored on Optical Disk

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