Aircraft Bulkhead Z-Section Prepreg Manufacturing to Prevent Wrinkles
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Solution Overview
Problem
Existing methods for manufacturing airplane frames with composite materials result in significant wrinkling during the fiber laying process due to differing arc lengths, affecting quality, and require multiple braiding mandrels leading to increased transportation costs.
Innovation Solution
A method involving Z-shaped airplane frames with specific braiding techniques, including biaxial and triaxial braiding, to form a prepreg that avoids wrinkling and allows for continuous use and transport of braiding mandrels, enhancing tensile and compression strengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional fiber bodies are curvedly laid on the mold, then the arc-shaped frame configuration can be achieved, but significant wrinkles are produced at the curved positions affecting quality
Solution Approach 1:
The fiber body is pre-formed into a cylindrical shape through braiding before being developed into a planar configuration. This preliminary cylindrical formation ensures that the fibers are already aligned and tensioned to follow the desired arc shape, preventing wrinkles when the planar braid is curvedly laid on the mold.
Solution Approach 2:
The fiber body undergoes a dimensional transformation from a planar flat configuration to a cylindrical three-dimensional configuration through braiding, then back to planar through development. This dimensional change allows the fibers to maintain tension and alignment along curved surfaces without wrinkling.
2Ease of manufacture
If dry fiber braiding combined with RTM molding is used, then the manufacturing process can be implemented, but more braiding mandrels are required resulting in higher transportation costs
Solution Approach 1:
The braiding mandrel is extracted from the final product and not reused. Instead of maintaining mandrels for continuous use, the process uses mandrels only during the brief braiding operation to form the cylindrical fiber body, then discards them after the planar braid is developed and used. This eliminates the need for multiple mandrels and reduces transportation costs.
Solution Approach 2:
The braiding mandrels are designed as disposable, single-use tools rather than expensive, long-lasting assets. This approach accepts the low cost of short-living mandrels to simplify the manufacturing process and eliminate complex mandrel management and transportation requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively prevents wrinkling and improves structural integrity while reducing transportation costs by utilizing continuous braiding mandrels and optimizing fiber alignment for improved mechanical properties.
Implementation Method 1
laying and then curing the cut prepreg to form the airplane frame
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to a manufacturing method for an aircraft bulkhead. The aircraft bulkhead is of an arc structure and comprises a Z-shaped cross section, and comprises a flanging area, bending areas, and a web area extending between the bending areas, wherein the web area is fan-shaped. The manufacturing method comprises the following steps: weaving a first fiber body on a weaving mandrel in an extension direction of the aircraft bulkhead according to the size of the aircraft bulkhead so as to form a cylindrical woven body; expanding the cylindrical woven body to form a flat woven body; pre-impregnating the flat woven body with resin to form a prepreg; cutting the prepreg according to the size of the aircraft bulkhead; and laying the cut prepreg and curing same to form the aircraft bulkhead. The manufacturing method of the present invention can solve the problem that folds are easily formed after the woven body is laid.