Investigation of Decoupling Material Performance with a Transmission Loss Model and Acoustic Intensity Measurements

Abstract

The complex dilatational moduli of three closed cell foam materials and one elastomeric material were determined by mechanical excitation of thin samples. The neoprene/EPT/SBR, polyvinylchloride, and ethylvinylacetate foams had moduli that ranged from 0.2 MPa to 3 MPa in the 100-900 Hz frequency range. The decoupling performance of these materials was then determined by applying them to steel substrates that were mechanically excited, and measuring the effect of the coatings on the radiated sound. Unlike previous studies where the test plates were supported at the comers and semi-submerged, in this study the plates were clamped at the edges and backed by an airfilled concrete enclosure. This "concrete box" was submerged into a water filled tank and the radiated sound was determined by intensity mapping in the near field of the plate.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1999
Accession Number
AD1003747

Entities

People

  • J. Y. Guigne
  • K. Klein
  • Qingcao Liu

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Classification
  • Concrete
  • Contractors
  • Contracts
  • Decoupling
  • Intensity
  • Losses
  • Materials
  • Materials Laboratories
  • Measurement
  • Near Field
  • Noise Reduction
  • Security
  • Transmission Loss

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Polymer Science and Engineering.
  • Structural Dynamics.