Development of Film-Infused Tougher Boron/Epoxy Ply
Abstract
A previous study has examined the fatigue properties of bonded joints representative of the boron-epoxy doublers bonded to the wing-pivot fittings of Royal Australian Air Force (RAAF) F-111C aircraft. These repairs indicated some fatigue damage and crack propagation occurred at the boron fiber to adhesive interface of the doubler. This paper reports studies that have investigated methods to improve the fracture toughness of the boron/epoxy laminate. Two types of specimen were prepared. In the first case the standard boron epoxy laminate was modified by co-curing FM73 adhesive film layers at the midplane. In the second case a standard laminate with two FM73 film infused layers at the midplane was prepared. The two modified laminates showed substantial increases in the fracture toughness, however, the co-cured FM73 laminate did not exhibit stable fracture. Failure analysis indicated that the three laminates specimens tested exhibited a complex fracture. Fracture either propagated at the boron-epoxy interface or within the resin or FM73 layers. Further improvement in fracture toughness of the laminate may be achieved by improving the boron to FM73 adhesion. The methods reported for improving laminate fracture toughness may potentially be employed for aircraft repairs in which very high stresses are known to be present.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2000
- Accession Number
- ADA385581
Entities
People
- Andrew Rider
- Ivan Stoyanovski
- Peter Chalkley
- Richard Muscat
Organizations
- Defence Science and Technology Group