Abstract: A lay-up method of composite aircraft parts with an opening. Composite tows having an orientation of 0°, 90° or +/?45° are laid up forming plies which form a composite laminate. Each tow having an orientation of 0° and being within the perimeter of the opening comprises: a first gap located at approximately ? of the length of the first semi-major axis from the center, the first gap being configured as a first elongated gap longitudinally perpendicular to the orientation of the tow, and a second gap located at approximately ? of the length of the second semi-major axis from the center, the second gap being configured as a second elongated gap longitudinally perpendicular to the orientation of the tow.

Abstract: A composite laminate (2) for an airframe lifting surface comprising a set of stacked plies (10) of pre-preg material, the composite laminate (2) being surrounded by at least an edge (3) following an edge direction E along the composite laminate (2), the set of stacked plies (10) including: a first plurality (4) of plies (4.1) formed by tapes arranged parallel to the edge direction E, and a second plurality (5) of plies (5.1, 5.2, 5.3) formed by tapes arranged in a direction different to the edge direction E, wherein the thickness of at least one ply of the second plurality (5) of plies is lower than the thickness of each ply of the first plurality (4) of plies.

Abstract: A composite laminate for an airframe lifting surface including: at least two sides and one ramp area defined by a decreasing staggered laminate extended along a ramp direction, wherein the composite laminate includes: first plies formed by tapes arranged parallel to the ramp direction, second plies formed by tapes arranged orthogonal to the ramp direction, third plies formed by tapes arranged in a first laying up direction, being the first laying up direction different from the ramp direction and the direction orthogonal to the ramp direction, and fourth plies formed by tapes arranged in a second laying up direction, being the second laying up direction different from the ramp direction, the direction orthogonal to the ramp direction and the first laying up direction; wherein in the ramp area, the tapes forming the third and/or fourth plies are extended from one laminate side to another laminate side.

Abstract: A composite laminate for an airframe lifting surface including: at least two sides and one ramp area defined by a decreasing staggered laminate extended along a ramp direction, wherein the composite laminate includes: first plies formed by tapes arranged parallel to the ramp direction, second plies formed by tapes arranged orthogonal to the ramp direction, third plies formed by tapes arranged in a first laying up direction, being the first laying up direction different from the ramp direction and the direction orthogonal to the ramp direction, and fourth plies formed by tapes arranged in a second laying up direction, being the second laying up direction different from the ramp direction, the direction orthogonal to the ramp direction and the first laying up direction; wherein in the ramp area, the tapes forming the third and/or fourth plies are extended from one laminate side to another laminate side.

Abstract: A composite laminate (2) for an airframe lifting surface comprising a set of stacked plies (10) of pre-preg material, the composite laminate (2) being surrounded by at least an edge (3) following an edge direction E along the composite laminate (2), the set of stacked plies (10) including: a first plurality (4) of plies (4.1) formed by tapes arranged parallel to the edge direction E, and a second plurality (5) of plies (5.1, 5.2, 5.3) formed by tapes arranged in a direction different to the edge direction E, wherein the thickness of at least one ply of the second plurality (5) of plies is lower than the thickness of each ply of the first plurality (4) of plies.

Abstract: Composite material part (11) with stringer (31) on ramp, manufactured from a stack of fabrics, which comprises at least one zone (13) with two sectors (17, 19) having a greater thickness than that of the surrounding zones and with the stringer (31) situated on an edge (21) of said zone (13) in which: a) each group of fabrics (27, 27? . . . ; 29, 29?, . . . ) of said sectors (17, 19) has the dimensions to form on said edge (21) a ramp with an acceptable gradient 1/p so that the stringer (31) remains situated on the ramp; b) the stacking of the zone (13) is carried out firstly by placing the fabrics (27, 27?, . . . ) of the first sector (17) and on these the fabrics (29, 29?, . . . ) of the second sector (19) in such a way that in the coinciding section (35) of said edge (21) the gradient of the resulting ramp is 1/(p/2).

Abstract: A manufacturing procedure of a composite material part (11), with an edge region (13) destined to be joined to another part by rivets, making a change in the geometry of said edge region (13) with respect to an initial surface (41) on the part's external face, comprising the following steps: a) providing a laying-up tool incorporating a modified surface (43) according to said change in the edge region (13) geometry; b) providing the composite material plies needed for the laying-up of the part, with the plies (51, 51?, . . . , 51n) destined for the edge region (13) of the part affected by the geometric modification being already cut so that they finish as they reach said modified surface (43); c) laying-up said plies over said tool and curing the resultant laminate. The invention also refers to a lower skin of an aircraft wing (11) manufactured according to said procedure.

Abstract: An aircraft lifting surface structured as a torsion box comprising upper and lower skins (19, 21) stiffened by span wise stringers (25, 25?, 25?), said aircraft lifting surface comprising one or more fuel tanks (31, 33, 35, 37) arranged inside of said torsion box and separated by bulkheads (41), the stringers (25, 25?, 25?) having extended feet in the intersection areas with said bulkheads (41), also comprising filler panels (45) of said skins (19, 21) covering the holes that remain between said skins (19, 21) and said bulkheads (41) outside said intersection areas, whose configuration is adapted for covering the space between the extended feet (26, 26?) of stringers (25, 25?), leaving a gap with them of a predetermined width (W1), thereby providing a self-fastening capability over each skin plane that facilitates the attachment of said filler panels (45) to said skins (19, 21).

Abstract: Procedure for the manufacture of a composite material part (11) having, at least, one reinforced area (13) of greater thickness than the surrounding areas, in which the dimensions and laying up sequence of the plies (21, 21?, 21?, 21??) that are used in the laying up step of said reinforced area (13), are determined so that, at least one of the plies (21?, 21?, 21??) crosses over the ply situated beneath it for reducing the volume of said reinforced area (13). The invention also refers to a composite material part (11) manufactured with said procedure, particularly a CFRP skin of an aircraft lifting surface.

Abstract: A manufacturing procedure of a composite material part (11), with an edge region (13) destined to be joined to another part by rivets, making a change in the geometry of said edge region (13) with respect to an initial surface (41) on the part's external face, comprising the following steps: a) providing a laying-up tool incorporating a modified surface (43) according to said change in the edge region (13) geometry; b) providing the composite material plies needed for the laying-up of the part, with the plies (51, 51?, . . . , 51n) destined for the edge region (13) of the part affected by the geometric modification being already cut so that they finish as they reach said modified surface (43); c) laying-up said plies over said tool and curing the resultant laminate. The invention also refers to a lower skin of an aircraft wing (11) manufactured according to said procedure.

Abstract: Composite material part (11) with stringer (31) on ramp, manufactured from a stack of fabrics, which comprises at least one zone (13) with two sectors (17, 19) having a greater thickness than that of the surrounding zones and with the stringer (31) situated on an edge (21) of said zone (13) in which: a) each group of fabrics (27, 27? . . . ; 29, 29?, . . . ) of said sectors (17, 19) has the dimensions to form on said edge (21) a ramp with an acceptable gradient 1/p so that the stringer (31) remains situated on the ramp; b) the stacking of the zone (13) is carried out firstly by placing the fabrics (27, 27?, . . . ) of the first sector (17) and on these the fabrics (29, 29?, . . . ) of the second sector (19) in such a way that in the coinciding section (35) of said edge (21) the gradient of the resulting ramp is 1/(p/2).