Accession Number : ADA135076

Title :   A Study of Polymer Matrix Fatigue Properties.

Descriptive Note : Final rept. Sep 79-Feb 83,

Corporate Author : WYOMING UNIV LARAMIE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Odom,E M ; Adams,D F

PDF Url : ADA135076

Report Date : Jun 1983

Pagination or Media Count : 120

Abstract : Hercules 3501-6 neat epoxy and Hercules X4001 neat bismaleimide specimens were fabricated and tested, both statically and in cyclic fatigue. Axial tensile and torsional shear loadings were utilized, at room temperature and 88 C. Detailed procedures are given for casting good quality specimens of these high performance structural polymers in neat (unreinforced) form. Techniques are also presented for gripping the specimens for mechanical loading, with special emphasis on problems which can be anticipated during fatigue cycling. Although there was scatter in the fatigue data for these relatively brittle polymers, the S-N curves exhibited a knee at about 10,000 cycles. That is, an endurance limit is suggested, which it may be possible to correlate with corresponding composite material response. Extensive scanning electron microscopy (SEM) was performed on the neat resin fracture surfaces. Failure initiation sites and a consistent pattern of crack propagation were exhibited. The observations suggest that the failures of the torsion specimens were consistently via tensile mode, characteristic of brittle materials. Correlations were made between the relative sizes of the fractures observed, and the static strengths and fatigue lives of the materials. (Author)

Descriptors :   *Polymers, *Matrix materials, *Fatigue, Composite materials, Epoxy resins, Polyimide resins, Tension, Loads(Forces), Cyclic tests, Static tests, Shear properties, Tensile properties, Torsion, Temperature, Fabrication, Brittleness, Fatigue life, Fracture(Mechanics), Surfaces, Crack propagation, Strength(Mechanics), Electron microscopy

Subject Categories : Laminates and Composite Materials
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE