Glass Fibre/Epoxy Resin Interface Life-Time Prediction.
Final rept. Apr 81-Apr 83,
BRISTOL UNIV (ENGLAND) H H WILLS PHYSICS LAB
Pagination or Media Count:
Chemical reaction, adsorption and diffusion in polymers are all enhanced by stress and, as is the case for other materials, localized stresses, since they initiate failures, are more important than overall levels of residual stress. The solutions contained inside interfacial pressure pockets are corrosive and their destructive action, on the bonds responsible for load transfer, is enhanced by residual interfacial stress. There exist no high resolution techniques for measuring localized deformation in non-crystalline materials. In crystals, however, local elastic strain can be detected and measured using Kossel X-ray diffraction and electron beam back scattering diffraction in the SEM, and convergent beam diffraction in the TEM. Each of these facilities has been used to study residual stress close to a-quartzepoxy resin interfaces in order to establish the general nature and magnitude of interfacial stress in SiO2epoxy composite materials including GRP. At 40mm from the interface local strain is 2. The corresponding large interfacial stresses are held responsible for the observed very strong dependence of mechanical damping on interfacial area.
- Laminates and Composite Materials
- Test Facilities, Equipment and Methods