A TENSOR-SKIN CONCEPT FOR CRASHWORTHINESS OF HELICOPTERS IN CASE OF WATER IMPACT

The "tensor-skin concept" was developed to improve the crashworthiness of composite helicopter structures in case of water impacts. This new skin concept can be used for the bottom shell of the fuselage of a helicopter. It contains polyethylene fiber/epoxy layers as part of a regular laminate and provides the skin with the capability to unfold and deflect by forming "plastic hinges", before it stretches and fails in tension. In this manner the skin is able to transfer transverse water pressure loads to the adjacent structure without fracturing. Results are presented of the first two phases of the investigation: an evaluation of one-dimensional and two-dimensional proof-of-concept specimens. A further development phase is being carried out to evaluate the tensor-skin at the structural panel level.