Accession Number : ADA305479

Title :   Investigation of Thermal Fatigue in Fiber Composite Materials.

Descriptive Note : Contract rept.,

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Fahmy, Abdel A. ; Cunningham, Thomas G.

PDF Url : ADA305479

Report Date : JUL 1976

Pagination or Media Count : 62

Abstract : Graphite-epoxy laminates were thermally cycled to determine the effects of thermal cycles on tensile properties and thermal expansion coefficients of the laminates. Three 12-ply laminate configurations were subjected to up to 5000 thermal cycles. The cumulative effect of the thermal cycles was determined by destructive inspection (electron micrographs and tensile tests) of samples after progressively larger numbers of cycles. After thermal cycling, the materials' tensile strengths, moduli, and thermal expansion coefficients were significantly lower than for the materials as fabricated. Most of the degradation of properties occurred after only a few cycles. The property degradation was attributed primarily to the progressive development of matrix cracks whose locations depended upon the layup orientation of the laminate. (MM)

Descriptors :   *FIBER REINFORCED COMPOSITES, *THERMAL FATIGUE, *GRAPHITE EPOXY COMPOSITES, TENSILE STRENGTH, DEGRADATION, COMPOSITE MATERIALS, TENSILE PROPERTIES, MODULUS OF ELASTICITY, ORIENTATION(DIRECTION), FRACTURE(MECHANICS), ELECTRON MICROSCOPY, THERMAL EXPANSION, EPOXY LAMINATES, FATIGUE(MECHANICS), TEMPERATURE COEFFICIENTS, THERMAL STRESSES, CYCLIC LOADS.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE