Methods for manufacturing curved omega stringers and z-shaped stringers of composite material and for manufacturing composite material stiffened panel with curvature

A Method for manufacturing curved omega stringers (1) of composite material, comprises the following steps: automatic tape lay up in an ATL machine or in an AFP machine or in a FLU machine and automatic cutting of the contour, after which a straight preform with reinforcements (7) is achieved, flat forming to get an omega shape (3) on the straight preform to transform it into a straight omega shaped preform (2), and a curve forming step, in which the straight omega shaped preform (2) is placed in a flexible tool (4) comprising a longitudinally embedded stiff band (9) and some laminate clampingmeans (8), the laminate clamping means (8) located in the extremes of the flexible tool (4), the flexible tool (4) being covered by mechanical closing means, such that the head of the straight omegashaped preform (2) has reinforcements (7) on both extremes, the reinforcements (7) being hold by the laminate clamping means (8) during the forming process, and afterwards the straight omega shaped preform (2) is heated and tr