Accession Number : ADA306025

Title :   Moisture Determination in Composite Materials Using Positron Lifetime Technique.

Descriptive Note : Technical rept.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Singh, Jag J. ; Holt, William H. ; Mock, Willis, Jr

PDF Url : ADA306025

Report Date : JUL 1980

Pagination or Media Count : 23

Abstract : Fiber-reinforced resin-matrix composites reportedly suffer significant degradation in their mechanical properties when they are exposed to hot, moist environments for extended periods. Moisture weakens the fiber-matrix bond as well as the matrix shear strength. Despite the importance of measuring moisture content and its effects on composite material properties, not enough data are available on suitable nondestructive techniques for detecting and measuring moisture diffusion in resin-matrix composite materials. This paper addresses the problem of measuring the moisture content of such materials, using the positron lifetime technique. (AN)

Descriptors :   *FIBER REINFORCED COMPOSITES, *POSITRONS, NONDESTRUCTIVE TESTING, DEGRADATION, CARBON FIBERS, MATRIX MATERIALS, MOISTURE CONTENT, SATURATION, GAMMA RAYS, DIFFUSION, EPOXY RESINS, HUMIDITY, WATER VAPOR, RADIOACTIVE DECAY, GRAPHITE EPOXY COMPOSITES, SHEAR STRENGTH, HALF LIFE, POLYIMIDE RESINS, ANNIHILATION RADIATION, POSITRONIUM.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE