CAI TechnologIes Mitigate RIsks of CertIfyIng Bonded Structures Published Dec. 12, 2006 By Plans and Programs Directorate AFRL/XP WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Thanks to the AFRL-sponsored Composites Affordability Initiative (CAI), the Department of Defense (DoD) supplier base now has access to a suite of tools and technologies enabling confident certification of bonded composite structures for primary load-bearing applications. The use of these resources will promote the development of more efficient concepts for air and space applications. The CAI team--which includes members from AFRL and the Navy, as well as industry representatives from Bell Helicopter Textron, Boeing, Lockheed Martin, and Northrop Grumman--took an aggressive approach to developing the technologies necessary for mitigating certification risks. The resulting product suite comprises advanced analysis tools to aid predictions regarding the onset and progression of failure mechanisms; process controls to improve the reliability of surface preparation and evaluation, adhesive mixing and dispensing, and assembly; and advanced inspection techniques to identify unique bond deficiencies and measure specific bond strength. These tools, along with a sound certification plan of analysis supported by testing, boost the confidence of certification authorities in trusting there are currently no technical barriers to certifying bonded structures. This represents a major breakthrough towards realizing the cost, cycle time, weight, and durability benefits associated with advanced bonded structures. Following the team's technology development achievement, the advanced analysis tools--which can accurately predict failure onset as well as progression--transitioned to commercial vendors. The capability to certify bonded airframe structures allows designers to create more efficient structural concepts. Compared to conventional, fastened structures, bonded structures offer reduced weight, which improves aircraft speed, range, payload, and loiter capability. Lighter-weight composite airframes will translate into fuel savings as well. Furthermore, the DoD can expect to leverage a projected 14% to 35% reduction in airframe acquisition costs and a 25% reduction in manufacturing cycle time for the production of airframe structures. Bonded structures will promote savings in other areas as well, reducing life-cycle costs (which dominate total weapon system ownership costs) by about 75% over fastened structures. This reduction will occur as corrosion-resistant composite structures begin to replace conventional aluminum airframes. The various combinations of these payoffs have application to a wide range of advanced weapon systems currently under consideration.