Abstract: A cast article having a reinforced structural composite core is disclosed. The cast article includes a structural element which is embedded in the otherwise cast metal article. The structural element is comprised of a metal matrix composite structural core. It includes a plurality of reinforcing fibers within a metal matrix. The fibers are generally a non-metallic material such as a ceramic which degrade at a temperature below the melting temperature of the cast metal comprising the article. The metal matrix composite structural core is encased with a sheath. The sheath, attached to and completely surrounding the core, is made of the same metal as the cast metal article. In a preferred embodiment, the article is a titanium alloy strut for a gas turbine engine.

Abstract: A cast article having a reinforced structural composite core is disclosed. The cast article includes a structural element which is embedded in the otherwise cast metal article. The structural element is comprised of a metal matrix composite structural core. It includes a plurality of reinforcing fibers within a metal matrix. The fibers are generally a non-metallic material such as a ceramic which degrade at a temperature below the melting temperature of the cast metal comprising the article. The metal matrix composite structural core is encased with a sheath. The sheath, attached to and completely surrounding the core, is made of the same metal as the cast metal article. In a preferred embodiment, the article is a titanium alloy strut for a gas turbine engine.

Abstract: A variable pitch blade and blade mount which is suitable for propellers, fans and the like and which has improved impact resistance. The invention is particularly directed to composite fan blades and blade mounting arrangements wherein the blades are permitted to pivot relative to a turbine hub about an axis generally parallel to the centerline of the engine upon impact of a large foreign object, such as a bird. By thus providing for the pivoting of the blades upon impact, centrifugal force recovery becomes the principal energy absorbing mechanism and a blade having improved impact strength is obtained.

Abstract: A rotor apparatus comprising a blade having a root adapted to swing laterally within a supporting spindle under impact loading is provided with a flow path defining platform. The platform comprises an inner shroud extending generally laterally of the blade airfoil portion and adapted to swing laterally therewith. In one embodiment wherein the blade primarily comprises a laminate of composite filament plies, the inner shroud is bonded to the laminate. An outer shroud, fixed with respect to the supporting spindle, forms a lateral extension of the inner shroud with the blade in its normal operating position. The inner and outer shrouds are provided with a pair of complementary adjacent surfaces contoured to pass in relatively close-fitting relationship to each other when the blade swings under impact loadings.

Abstract: A turbomachinery blade platform comprising a pair of complementary platform halves, each having an outer flow path defining shroud adapted to extend generally laterally of the blade. An inner flange on each platform half, also extending generally laterally of the blade, is retained in a cooperating slot formed within the support structure retaining the blade. A structural member extending between the shroud and the flange is contoured to conform to an overlapping wedging surface disposed about the blade airfoil surface. The platform is thus provided with redundant retention by both the blade and by the blade support structure.