PRIMARY ENGINE STRUT STRUCTURE OF AN AIRCRAFT
The disclosed embodiments relate to a primary engine strut structure of an aircraft characterized in that it includes single-piece composite panels while replacing the metallic spars and metal panels, the composite panels having a lay-up of fibers oriented along crosswise directions whereby integrating, in the width of the skin of the panles, a lattice structure that replaces longitudinal and transversal stiffeners of the spars and metal panels.
1 . An aircraft engine ( 9 ) strut ( 11 ) primary structure characterized in that it comprises composite one-piece panels ( 1 a , 2 a, 3 a, 4 a ) to replace metal spars ( 1 , 2 ) and metal panels 3 , 4 , said composite panels comprising a layup ( 12 ) of the fibers orienting these fibers in crossing directions so as to incorporate into the thickness of the skin of the panels a mesh structure that replaces the longitudinal ( 13 ) and transverse ( 14 ) stiffeners of the metal spars and panels.
2 . The aircraft engine strut primary structure as claimed in claim 1 , characterized in that the lateral panels ( 1 a , 3 a ) of the structure are composite panels.
3 . The aircraft engine strut primary structure as claimed in claim 2 , comprising fittings for attaching the engine to the strut and for attaching the strut to the wing structure ( 10 ) of the aircraft, characterized in that at least some of the fittings ( 7 a ) are incorporated into the composite lateral panels ( 1 a , 3 a ).
4 . The aircraft engine strut primary structure as claimed in claim 3 , characterized in that the fittings ( 7 a ) incorporated into the composite lateral panels are fittings for attaching the strut to the wing structure ( 10 ).
5 . The aircraft engine strut primary structure as claimed in claim 2 , characterized in that with the composite lateral panels comprising inspection holes ( 8 a, 8 b, 8 c ) the layup of the composite lateral panels includes reinforcing regions ( 15 ) around the inspection holes.
6 . The aircraft engine strut primary structure as claimed in claim 1 , characterized in that it comprises at least one composite upper spar ( 2 a ) provided with rims ( 16 , 17 ) for connection to the composite lateral panels ( 1 a , 3 a ).
7 . The aircraft engine strut primary structure as claimed in claim 4 , characterized in that the composite upper spar 2 a is produced using a layup of the highly oriented ( 50 / 20 / 20 / 10 ) type.
8 . The aircraft engine strut primary structure as claimed in claim 6 , characterized in that the layup of said composite upper spar ( 2 a ) is reinforced in the regions ( 18 ) where load will be introduced.
9 . The aircraft engine strut primary structure as claimed in claim 1 , comprising an engine mount ( 5 a ) supporting a front fixing ( 6 ) for attaching the strut to the engine ( 9 ), characterized in that at least the beams of the engine mount are made of composite materials.
10 . The aircraft engine strut primary structure as claimed in claim 1 , characterized in that the layup of the composite panels is a layup of the quasi-isotropic type.