Honeycomb Fastening 700850

Attachment of honeycomb sandwich structure has been an important design consideration in the aerospace field since the early 50's when bonded sandwich was first used extensively as covering for the wings and tail of the supersonic B-58. Since then, virtually all military and an increasing number of commercial aircraft and space vehicles utilize honeycomb sandwich as primary structure. This paper illustrates the basic approaches to sandwich panel attachment and the variety of typical solutions. Successful honeycomb fastening design concepts from B-58, B-57F, and F-111 production programs at General Dynamics are illustrated. Sealing of sandwich joints for use as integral fuel tanks and application of specialty fasteners for honeycomb sandwich are discussed. Structural efficiency of “fastened” stepped-down edge concepts versus full-depth panel edges is compared. A full-depth panel edge design with a stud and plug with spliceplate is currently an attractive design for fastening both metallic and composite-faced sandwich.