Rapid High Quality Field Repair Methods for Thick Section Composite Vehicle Structures

Field repair methods for composite aircraft structures fail to account for the unique materials, construction and failure modes associated with thick section fiberglass composite combat vehicle structures. Although acceptable repair techniques for thick laminates have been demonstrated in the laboratory, most viable techniques require the application of heat to cure an adhesive or resin. Heating blankets, hot air, heat lamps and solar radiation are field deployable, but they all rely on heat transfer from the surface through the thick, low thermal conductivity laminate. Depending on the environment, it may take many hours to effectively cure through the thickness of the laminate. Such a lengthy procedure could severely tax field maintenance assets. In or near a combat zone, time is a life or death matter. Foster-Miller proposes a practical means to drastically reduce the time required to effect high quality field repairs. Our method would combine two proven thick laminate repair methods, resin injection and through-thickness fasteners, with an ultra-rapid, simple and safe microwave heating method. We believe that this method has the potential to reduce field repair time from many hours to less than an hour. In Phase I, we will demonstrate that a man-portable microwave hood, comprised of low cost commercially available components, can be used to rapidly and safely heat repair adhesives injected into interior delamination surfaces in a fiberglass laminate. Our team member, FMC, has agreed to provide samples at no cost to the program. In Phase II, detailed repair procedures will be developed, validated, and catalogued in a field repair handbook.