Investigation of the Crash Impact Characteristics of Composite Airframe Structures

The results of a joint Bell/Grumman contracted effort with the Army are discussed. The effort was directed toward the investigation of the crash impact characteristics of advanced troop transport helicopter airframe structures constructed of composite materials. Currently available information was surveyed on the crash impact behavior of composite materials, analytical tools for design of crashworthy airframe structures and airframe structure crashworthiness design criteria. Information on the crash impact behavior of composite materials was found to be limited. An automotive study showed that by innovative design, composite materials could function efficiently as energy absorbers to reduce crash impact loads. Other pertinent studies were found that are currently in progress at Bell Helicopter Textron, the NASA Langley Research Center and the U. S. Army's Research and Technology Laboratories and are summarized. Finally, effects of composite materials on the compliance of airframe structures with current Army crashworthiness requirements are discussed.