A method of manufacturing curved composite structural elements can include fabricating a web ply in a flat curve over a removable substrate and laying up the ply on a curved web surface of a manufacturing tool. The method also can include laying up a diagonal ply with fibers oriented at +/−45° from the centerline of the web surface. The method further can include cutting a unidirectional composite tape into segments and laying up the tape segments to form a cross ply with a fiber orientation normal to the centerline of the web surface. One or both edges of the diagonal and cross plies may be folded over one or two sides of the manufacturing tool to form one or two flange surfaces. Additionally, a cap ply can be laid up on one or both flange surfaces using composite tape. The structural element layup can then be inspected and any excess composite material can be trimmed away.

Method of manufacturing curved composite structural elements

A contoured composite structure is fabricated by laying up a composite charge that includes at least one ply formed by uni-directional fiber pre-preg ply segments having substantially constant widths. The ply segments are placed in side-by-side, overlapping relationship with their longitudinal centerlines aligned in a polar orientation related to the contour of the structure. The charge is formed into the shape of the structure and cured.

Method for producing contoured composite structures and structures produced thereby

Provided are: a curved reinforcing fiber substrate (1) characterized by having a curved planar shape and by comprising reinforcing fiber yarns (2) arranged parallel with a direction along a circumferential direction (3) of the curved shape and auxiliary weft yarns (4) arranged in directions crossing a plurality of the reinforcing fiber yarns (2) each arranged in one direction of the circumferential direction (3); a curved reinforcing-fiber layered product using the substrate; a preform; a reinforced composite material; and processes for producing those. These can be provided as: a reinforcing fiber substrate curved along the longitudinal direction and arranged with reinforcing fibers along the curved shape in a desirable formation; a curved reinforcing-fiber layered product layered with at least one layer of the reinforcing fiber substrate and a process for producing the layered product efficiently in a short time; a preform using the layered product and a process for forming the preform efficiently; and a long-extended curved fiber-reinforced composite material and a process for producing the same.

Reinforcing fiber base of curved shape, layered product employing the same, preform, fiber-reinforced resin composite material, and processes for producing these

A curved composite aircraft frame comprises a multi-ply composite laminate having a generally Z-shaped cross section. At least certain of the laminate plies include unidirectional reinforcing fibers that are substantially tangent at substantially all points along the curvature of the frame.

Curved composite frames and method of making the same

Apparatus and techniques for providing a closed hat stringer are disclosed. In one embodiment, a closed hat stringer for stiffening a composite structure includes opposing cavity walls situated between a first flange and a second flange, the cavity walls, first flange and second flange defining an elongated cavity, the second flange including a continuous exterior surface having a width greater than the first flange and configured for attachment to a skin.

Bladderless Mold Line Conformal Hat Stringer

Method for manufacturing an elongate structural element and a rigid shell structure integrated with at least one elongate stiffening element. The method includes the steps of providing a preformed, form-stable former (16), which has a hat profile with two inwardly directed, opposing flange portions (20), covering the former with a curable composite material to form an external hat profile (24, 26) having outwardly directed flanges (26), and integrating this assembly (16, 24, 26) with either a curable or preformed shell structure (10) of composite material.

A method of manufacturing an elongate structural element configured for stiffening a shell structure, and a method for manufacturing a rigid shell structure integrated with at least one elongate stiffening element

A method for fabricating a curved beam from fiber composite material. A flat fiber composite laminate including a plurality of layers and at least two different fiber directions is formed. The fiber composite laminate is disposed in contact with a male tool includes a first flange, a second flange and an intermediate web. The male tool is curved in its longitudinal direction with a radius of curvature in such a way that the first flange has a shorter longitudinal extent than the second flange. The fiber composite laminate is brought into contact with and secured to the first flange of the male tool. The male tool and the fiber composite laminate are then rotated relative to one another so that the fiber composite laminate is brought into contact with the intermediate web of the male tool in a first rotational movement, and brought into contact with the second flange of the male tool in a second rotational movement. The fiber composite laminate hardens on the male tool, and the finished beam is separated from the tool. Also a beam of fiber composite material fabricated according to the method.

Method for fabricating a curved beam from composite material

A curved beam of fiber composite material. The beam includes a first flange curved in a longitudinal direction, a second flange curved in a longitudinal direction and having a greater longitudinal extent than the first flange, and a web curved in a longitudinal direction and extending between the first flange and the second flange. The beam includes a fiber composite laminate including layers of fibers having different fiber directions, wherein a fiber density per unit of area of the second flange is lower than a fiber density per unit of area of the first flange, and wherein the first flange, the second flange and the web are seamless, continuous, and unfolded in a longitudinal direction.

Curved beam of fiber composite material

A method for producing an object of composite material comprising the steps of: placing one or several prepregs on a plane surface, forming a fibre stack; lifting over the fibre stack to a moulding tool; downforming the fibre stack; curing the downformed fibre stack; where the method also comprises the step of: orienting the fibre directions so that all fibres, when the fibre stack is lifted over to the moulding tool, will cross an edge of the moulding tool only once.

Manufacturing method for trumpet spar and other curved objects

The present invention relates to a method for the fabrication of a former for manufacture of composite articles. The method is characterized by the following steps: forming a wetted water-soluble fiber composite on a master tool such that the fiber composite material lies against a surface area of the master tool, allowing the water-soluble fiber composite to dry on the master tool and removing the dry water-soluble fiber composite from the master tool, wherein the dry fiber composite forms the walls of the thus fabricated former. The invention also relates to the manufacture and repair of articles using said former

Bjoern Weidmann

Papers

A method of manufacturing an elongate structural element configured for stiffening a shell structure, and a method for manufacturing a rigid shell structure integrated with at least one elongate stiffening element

Method for fabricating a curved beam from composite material

Curved beam of fiber composite material

Manufacturing method for trumpet spar and other curved objects

Method for the fabrication of a former for manufacture of composite articles and manufacture and repair of composite articles using said former