A HYBRID COMPOSITE FLEXBEAM FOR A HELICOPTER BEARINGLESS MAIN ROTOR ASSEMBLY

摘要

A hybrid composite flexbeam (10) for a soft inplane bearingless main rotor assembly (100) has eight spanwise regions: a hub attachment region (12); a first tapered region (14); a second tapered region (16); an inboard transition region (18); a pitch region having a cruciform configuration (20); an outboard transition region (22); a tapered outboard transition region (24); and a main rotor blade, torque tube attachment region (26). The pitch region (20) is formed from unidirectional fiberglass plies, a 50/50 admixture of unidirectional fiberglass and graphite plies, and unidirectional graphite plies. Unidirectional fiberglass and graphite plies of varying lengths are interleaved in the second inboard tapered region (16). Fiberglass and graphite cross plies of varying lengths are interleaved in the first inboard tapered region (14). Fiberglass and graphite cross plies and unidirectional fiberglass plies of varying length are interleaved in the outboard tapered region (24). The distributed arrangement of ply endings cause kick loads (97) in the hybrid flexbeam (10) to be distributed across the ply buildups.