Abstract: A composite structural element comprising a substantially planar main section defining a coordinate system with a first axis extending along a longitudinal axis of the structural element and a second axis extending perpendicular to the longitudinal axis within the planar main section. The structural element contains a basic lay-up of single plies, each comprising a fiber-reinforced composite material with a substantially unidirectional fiber orientation. The lay-up comprises N plies arranged from top to bottom in the following form: [[?, ?]M; [?]K; [?, ?]M], wherein ?, ? and ? represent one ply having an angle enclosed between the first axis and the unidirectional fiber orientation of the one ply, respectively, [x]y means y plies each having angle x; [x, y]z means z pairs of plies, K and M are both positive integers equal to or greater than 1: N=4·M+K.

Abstract: A composite structural element comprising a substantially planar main section defining a coordinate system with a first axis extending along a longitudinal axis of the structural element and a second axis extending perpendicular to the longitudinal axis within the planar main section. The structural element contains a basic lay-up of single plies, each comprising a fiber-reinforced composite material with a substantially unidirectional fiber orientation. The lay-up comprises N plies arranged from top to bottom in the following form: [[?, ?]M; [?]K; [?, ?]M], wherein ?, ? and ? represent one ply having an angle enclosed between the first axis and the unidirectional fiber orientation of the one ply, respectively, [x]y means y plies each having angle x; [x, y]z means z pairs of plies, K and M are both positive integers equal to or greater than 1: N=4·M+K.

Abstract: This relates to a composite structural element, in particular a rib or a spar, specifically for use in a torsion box of an aircraft structure such as a vertical tailplane, wherein the structural element defines a coordinate system with a first axis “a” wherein the structural element comprises a substantially planar main section defining a coordinate system with a first axis “a” extending along the longitudinal axis “L” of the structural element and a second axis “b” extending perpendicular to said longitudinal axis “L” within the planar main section and defining an angle of +90° with the first axis “a”, wherein the structural element contains a lay-up of single plies consisting of a fiber-reinforced composite material with a substantially unidirectional fiber orientation.

Abstract: This relates to a composite structural element, in particular a rib or a spar, specifically for use in a torsion box of an aircraft structure such as a vertical tailplane, wherein the structural element defines a coordinate system with a first axis “a” wherein the structural element comprises a substantially planar main section defining a coordinate system with a first axis “a” extending along the longitudinal axis “L” of the structural element and a second axis “b” extending perpendicular to said longitudinal axis “L” within the planar main section and defining an angle of +90° with the first axis “a”, wherein the structural element contains a lay-up of single plies consisting of a fiber-reinforced composite material with a substantially unidirectional fiber orientation.