DEVELOPMENT OF THE SHIM JOINT CONCEPT FOR COMPOSITE STRUCTURAL MEMBERS.
Abstract
Several methods have been proposed for attaching to the ends of structural tubes fabricated from composite materials, but few have been studied in detail. This program was initiated to study the shim joint concept in detail as subjected to tension loads. The shim joint concept permits a conventional pin joint between the composite tube end and a mating metal fitting by reinforcing the composite material with thin metallic layers. Shim joints were studied during this program as applied to glass reinforced plastic tubes. Corrosion resistant steel (AM 355, 260 ksi) was used as a reinforcement material. An attempt was made to extend shim joint technology by (1) defining through analyses the critical failure modes and pertinent design parameters for tension loads; (2) establishment of design allowables for each of the failure modes through tensile testing of single pin, flat plate specimens; (3) development of a rational design procedure for the shim reinforced tube end; (4) development of improved methods for fabrication and machining of the reinforced tube end; and (5) fabrication and test of full scale tubular joints in test weight end fittings. It was shown during this program that glass composite tubes can be successfully reinforced with AM 355 foil to develop the ultimate load in the tube without prohibitive attachment weight penalties. An optimization routine was used in the design procedure to aid in determining the minimum weight configuration. The bond joint strength was increased significantly during the program by incorporating an adhesive film between the metallic and fibrous layers. A joint, designed to transmit 150 kips to a 3.0 inch OD tube, added only 0.35 pound to the basic tube weight. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1967
- Accession Number
- AD0821137
Entities
People
- A. L. Courtney
- B. W. Cole
- J. P. Wong