Accession Number : ADA305024

Title :   Acoustic Emission Testing of Composite Vessels Under Sustained Loading.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Lark, R. F. ; Moorhead, P. E.

PDF Url : ADA305024

Report Date : 11 OCT 1978

Pagination or Media Count : 25

Abstract : This paper describes a study of the acoustic emissions (AE) generated from Kevlar 49/epoxy composite pressure vessels subjected to sustained load-to-failure tests. The AE data from two different transducer locations on the vessels were compared. It was found that AE from vessel wall-mounted transducers showed a wide variance from those for identical vessels subjected to the same pressure loading. AE from boss-mounted transducers did, however, yield values that were relatively consistent. It appears that the signals from the boss-mounted transducers represent an integrated average of the emissions generated by fibers fracturing during the vessel tests. The AE from boss-mounted transducers were also independent of time for vessel failure. This suggests that a similar number of fiber fractures must occur prior to initiation of vessel failure. These studies indicate a potential for developing an AE test procedure for predicting the residual service life or integrity of composite vessels. (MM)

Descriptors :   *FIBER REINFORCED COMPOSITES, *POLYAMIDE PLASTICS, *PRESSURE VESSELS, *ACOUSTIC EMISSIONS, FILAMENT WOUND CONSTRUCTION, SYMPOSIA, LIFE EXPECTANCY(SERVICE LIFE), COMPOSITE MATERIALS, LOADS(FORCES), COMPOSITE STRUCTURES, RUPTURE, FRACTURE(MECHANICS), LIGHTWEIGHT, TRANSDUCERS, EPOXY COMPOSITES, FAILURE(MECHANICS), EPOXY RESINS, STRESS WAVES, CREEP TESTS, WINDING, BURSTING STRENGTH.

Subject Categories : Laminates and Composite Materials
      Plastics
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE