Accession Number : AD0715712

Title :   Study of the Onset of Permanent Deformation in Structurally Bonded Joints.

Descriptive Note : Final rept.,

Corporate Author : AUBURN UNIV ALA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Jemian,Wartan A.

Report Date : NOV 1970

Pagination or Media Count : 99

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)

Descriptors :   (*BONDED JOINTS, DEFORMATION), (*STRUCTURAL MEMBERS, LOADS(FORCES)), SHEAR STRESSES, CRACKS, NUCLEATION, BONDING, EPOXY RESINS, MATHEMATICAL MODELS, COMPUTER PROGRAMS

Subject Categories : Couplers, Fasteners, and Joints
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE