Method of Fabricating Fiber Reinforced Composite Structure Having Stepped Surface
AssigneeThe Boeing Company
InventorsAndrew E. Modin, Jack A. Woods, Robert D. Hawkins
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Abstract
Fiber reinforced composite structures having curved stepped surfaces are fabricated by laying up plies of fiber reinforced material over a tool having a stepped tool feature. The plies are rotated about a fixed axis as they are laid up to substantially form a fixed axis rosette pattern. The plies are angularly oriented such that at least certain of the plies have fiber orientations other than 0, +45, −45 and 90 degrees. Potential bridging of the fibers over the stepped tool features is reduced or eliminated by cutting slits in the plies in the area of the stepped features, so that the plies can be fully compacted.
Claims21
A method of fabricating a fiber reinforced composite structure having a curved stepped surface, comprising the steps of:
- (A) laying up a plurality of fiber reinforced material plies in a fixed axis rosette pattern over a tool having a curved stepped tool surface;
- (B) forming an opening in each of the plies in the area of the stepped surface;
- and,
- (C) consolidating the plies.
A method of fabricating a composite structure reinforced with stiff fibers and having a curved stepped feature, comprising the steps of:
- (A) providing a plurality of reinforcement plies of material;
- (B) arranging at least certain of the plies over a tool such that at least certain of the fibers bridge over the stepped feature;
- (C) cutting the certain fibers in the area of the stepped feature;
- and,
- (D) compacting the plies.
A method of fabricating a window frame for an aircraft, wherein the frame includes a curved joggle surrounding a central window opening, comprising the steps of:
- (A) providing a tool having curved stepped tool surfaces for forming the curved joggle in the frame;
- (B) providing a plurality of plies of composite material reinforced with fibers each having an axis of orientation;
- (C) laying up the plies over the tool such that the axes of fiber orientation for the plies radiate substantially from a fixed point;
- (D) forming a slit in areas of each of the plies where the fibers in the plies cross the curved joggle;
- and,
- (E) consolidating the plies.
Dependencies are inferred from the claim text.