Study of the Onset of Permanent Deformation in Structurally Bonded Joints.
Abstract
Deformation mechanics of structurally bonded joints and coated metallic single crystals was studied from both the phenomenological and mechanistic points-of-view. The polymer coating was observed to allow the normal initiation of slip, but slip was limited on each plane by the stretched polymer. This accounts for a coating effect comparable in magnitude to those of some metallic and ceramic coatings. A pronounced polymer stiffening was observed after a critical amount of strain in both coated single- crystal samples and bonded lap-shear and symmetrical double-lap joint configurations prior to crack nucleation. A separate stress analysis showed that the surface of the joint at the loading edge and at the tip of a crack along the overlap is subjected to tearing stresses only. A fracture toughness test method using lap-shear samples was developed to determine the fracture toughness by the strain energy release rate method in the opening mode. The results confirm those reported from studies on a similar system but in a different sample configuration. (Author-PL)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1970
- Accession Number
- AD0715712
Entities
People
- Wartan A. Jemian
Organizations
- Auburn University