Increasing Strengths of Boron Fiber and Graphite Fiber Plastic Composites.

Abstract

Prestressing of boron/epoxy prepreg tape material yields com-posites with substantial improvements in both average tensile strength and standard deviation over that obtained with conven-tional prepreg to laminate processing. The process has a fundamental effect on the prepreg fiber strength properties by prebreaking the fibers at their weak sites, and these induced changes are then carried into the composite as a reduction in property dispersion. The effects of processing parameters are evaluated by characterizing the details in the fiber strength distributions. The induced changes in fiber strength distri-bution are correlated with the composite strength properties. Prestressing essentially performs a quality control function on commerical type prepreg by reducing the inherent variability of unprocessed material. Fracture mode control has also been demonstrated for boron/ polyimide systems by a laminating method of alternating layers of resin rich and fiber rich prepreg mater-ial. (Author, modified-PL)

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1971
Accession Number
AD0919963

Entities

People

  • Gary G. Brown
  • George J. Mills
  • W. M. Wochos

Tags

DTIC Thesaurus Topics

  • Composite Materials
  • Dispersions
  • Graphitic Materials
  • Laminates
  • Materials
  • Prestressing
  • Quality Control
  • Standards
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Reinforced Composite Materials