High modulus hybrid material rotor blade spar
AssigneeSikorsky Aircraft Corporation
InventorDavid A. Darrow, Jr.
Life of this patent
Estimating the term…
Abstract
A composite spar having an upper and lower wall region connected by leading and trailing edge regions is provided including a plurality of first laminates and a plurality of second laminates. The plurality of first laminates includes one or more intermediate modulus graphite plies having an intermediate modulus. The plurality of first laminates is arranged in one or more intermediate modulus layers to form at least a portion of the upper wall region, lower wall region, leading edge region and trailing edge region. The plurality of second laminates includes one or more high modulus graphite plies having a high modulus. The plurality of second laminates is arranged in one or more high modulus layers. The high modulus layers are generally interposed between intermediate modulus layers.
Claims15
A composite spar having an upper and lower wall region connected by leading and trailing edge regions, the spar comprising:
- a plurality of first laminates including one or more plies of graphite fibers having an intermediate modulus, the plurality of first laminates being arranged in one or more intermediate modulus layers, each of the intermediate modulus layers extends about a periphery of the spar;
- and
- a plurality of second laminates including one or more plies, wherein each ply of the one or more plies of each of the plurality of second laminates includes graphite fibers having a high modulus, which is higher than the intermediate modulus, the plurality of second laminates being arranged in one or more high modulus layers, the high modulus layers being generally interposed between intermediate modulus layers, and a total number of plies in the high modulus layers is greater than a total number of plies in an adjacent intermediate modulus layer, wherein each of the plurality of second laminates overlaps a portion of an adjacent one of the plurality of first laminates.
A method of forming a spar, comprising:
- wrapping an intermediate modulus layer including one or more plies of graphite fibers having an intermediate modulus about a periphery of a mandrel;
- arranging a high modulus layer including one or more plies, over a portion of the intermediate modulus layer, wherein each ply of the one or more plies in the high modulus layer includes graphite fibers having a high modulus and a total number of plies in the high modulus layer is greater than a total number of plies in an adjacent intermediate modulus layer;
- and
- positioning another intermediate modulus layer about the periphery of the mandrel such that the high modulus layer is interleaved between the intermediate modulus layer and the another intermediate modulus layer, wherein layers of the spar having one or more plies of graphite fibers having an intermediate modulus extend about the periphery of the mandrel.
A rotor blade for a rotary wing aircraft, comprising:
- a substantially hollow spar, the spar including:
- a plurality of first laminates including one or more plies of graphite fibers having an intermediate modulus, the plurality of first laminates being arranged in one or more intermediate modulus layers, each of the intermediate modulus layers extending about a periphery of the spar;
- and
- a plurality of second laminates including one or more plies, wherein each ply of the one or more plies of each of the plurality of second laminates includes graphite fibers having a high modulus which is higher than the intermediate modulus, the plurality of second laminates being arranged in one or more high modulus layers, the high modulus layers being generally interposed between intermediate modulus layers, a total number of plies in the high modulus layer is greater than a total number of plies in an adjacent intermediate modulus layer, wherein each of the plurality of second laminates overlaps only a portion of an adjacent one of the plurality of first laminates;
- a plurality of airfoil blocks positioned about the spar to define an airfoil shape;
- and
- at least one skin extending around an exterior of the plurality of airfoils blocks to define a smooth exterior surface.
Dependencies are inferred from the claim text.