Integrated composite skin for aircraft mid-box lifting surfaces
A composite skin ( 11 ) with swept angle and dihedral for an aircraft mid-box lifting surface having a left side ( 5 ), a right side ( 7 ) and a central transition area ( 9 ) where both sides meet, that is designed and manufactured as a single part from left tip to right tip following a common ply structure for the whole part defined in relation to a single orientation rosette ( 25 ). The invention also refers to a composite aircraft mid-box lifting surface including an upper and lower panel with said composite skin ( 11 ).
1. A composite skin for an aircraft mid-box lifting surface defining swept and dihedral angles and including a left side, a right side and a central transition area where the left and right sides meet, the composite skin comprising:
at least one ply extending from a first tip of the lifting surface on one of the two sides to a position in the central transition area, and
a further ply overlaying the at least one ply, wherein the further ply is a continuous ply which extends from the first tip to a second tip of the other of the two sides of the lifting surface to form a composite skin having a common ply structure; and
wherein said skin has been manufactured as a single structure following a common ply structure for the whole part defined in relation to a single orientation rosette.
2. A composite skin according to claim 1 , wherein the common ply structure includes continuous plies shared by said left and right sides and non-continuous plies that are dropped-off at said central transition area.
3. A composite skin according to claim 1 , wherein the stacking sequences of said left and right sides are symmetrical with regard to the aircraft longitudinal axis.
4. A composite skin according to claim 1 , further comprising an external continuous ply in at least one of its surfaces.
5. A composite skin according to claim 1 , wherein the composite skin is made of a material including carbon fibers impregnated with thermoset resin.
6. A composite aircraft mid-box lifting surface including an upper and lower panel having left and right sides, wherein the skin of said panels are made of a composite skin according to claim 1 .
7. A composite skin according to claim 1 , wherein the at least one and the further plies are laid with reference to global orientation reference so as to be compatible with main load paths of the left and right sides.
8. A method for manufacturing a composite skin according to claim 1 , comprising the steps of:
laying the at least one ply from the first tip to the central transition area, and
laying the further ply over the at least one ply continuously from the first tip to the second tip.
9. A method for manufacturing a composite skin according to claim 1 ; further comprising selecting a global orientation reference such that the first and second plies are laid in an orientation that is compatible with main loading paths of the left and right sides.