This Small Business Innovative Research (SBIR) Phase I project will evaluate a blind structural fastening technique that is thought to be superior to riveted joints. Riveting is the preferred method for assembly of load-bearing aluminum and titanium airframe structures; however, this process requires high loads and access to both sides of the structure. Phase I will analyze and test the mechanical performance of a low-impact fastener inflation approach for structural joining. This approach requires access to only one side of a structure, greatly simplifying fastener installation. The Phase I project will perform: numerical analysis of the mechanics of fastener installation; an experiment to verify fastener loads and deformation; and test the strength of fastened test coupons. Design specifications will be made for a low-cost fastener and a compact, low-impact-fastening tool suited for manual or robotic installation. Airframe assembly is a major cost of military and commercial aircraft. This fastener technology is expected to halve the cost of manual airframe fabrication and can be used in an automated, flexible-manufacturing environment. It may eventually be extended to fastening of a wide variety of aluminum, titanium, and composite structures for automotive, transport, and civil engineering structures.
