Accession Number : ADA140260

Title :   Effects of Stress on Permeation and Polyurethane Degradation.

Descriptive Note : Final rept.,


Personal Author(s) : Cassidy,P E

PDF Url : ADA140260

Report Date : 01 Mar 1983

Pagination or Media Count : 18

Abstract : Water permeation through elastomers and plastics has been studied for many years. The past ten years have witnessed increased interest in this phenomenon in regard to failure modes and expected lifetimes of sonar transducers. The basis of this concern lies in the fact that transducer design often calls for rubber to be the primary barrier to seawater penetrating into the electroacoustic spaces of the transducer. A seemingly very important consideration that has been overlooked up to now is the effect of stress on the permeability of the rubber barrier. Two types of stress are commonly present when rubber is used in transducers: a static stress due to the rubber being stretched; and a dynamic stress resulting from the rubber being subjected to acoustic vibration. If these factors affect water permeation, then the behavior and lifetime of the transducer will differ from that expected.

Descriptors :   *Polyurethane resins, *Stress analysis, *Failure(Mechanics), Sonar transducers, Degradation, Permeability, Coefficients, Stability, Sonar transducers, Sea water, Barriers, Rubber, Neoprene, Tensile strength, Aging(Materials), Hardness, Life expectancy(Service life), Deformation, Strain(Mechanics), Transducers

Subject Categories : Plastics
      Acoustic Detection and Detectors
      Ammunition and Explosives

Distribution Statement : APPROVED FOR PUBLIC RELEASE