Composite Aircraft Door Structure for Low-Weight Stiffness
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Solution Overview
Problem
Aircraft doors are traditionally made of metal due to stiffness requirements, which are costly and heavy, while composite materials are used for other components to reduce weight and cost.
Innovation Solution
A composite aircraft door design featuring an outer skin with attached outer blades and an inner skin with attached inner blades, both made of composite plastic material, arranged orthogonally to provide stiffness and ease of manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal materials are used for aircraft doors to ensure stiffness, then structural strength is improved, but weight increases and manufacturing cost increases
Solution Approach 1:
The patent applies composite plastic materials (specifically thermoplastic composite materials) to manufacture the entire aircraft door structure, replacing traditional metal materials. The composite door structure comprises a composite frame with composite web parts and composite cover plates, achieving both weight reduction and maintained structural strength through the inherent properties of composite materials.
Solution Approach 2:
The patent changes the material parameter from metal to composite plastic material, which has lower density and different mechanical properties. This parameter change enables weight reduction while maintaining structural integrity through optimized composite material selection and structural design.
2Strength
If metal materials are used for aircraft doors to ensure stiffness, then structural strength is improved, but manufacturing cost increases
Solution Approach 1:
The patent uses composite plastic materials that can be manufactured through molding processes, reducing the need for complex metal forming operations. The composite door structure integrates frame and cover plate manufacturing into streamlined processes, lowering overall manufacturing cost while maintaining structural strength.
Solution Approach 2:
The patent merges the manufacturing of the composite frame and composite cover plates into an integrated structure. The composite web parts of the frame connect the side beams and serve as mounting structures for cover plates, simplifying assembly and reducing manufacturing complexity.
3Weight of moving object
If composite materials are used for aircraft doors to reduce weight, then weight is reduced, but structural stiffness becomes insufficient
Solution Approach 1:
The patent employs thermoplastic composite materials which provide high strength-to-weight ratio. The composite structure is designed with optimized fiber orientation and layering to achieve sufficient stiffness while maintaining weight advantages over metal construction.
Solution Approach 2:
The patent applies local quality enhancement through the composite frame structure where web parts are strategically positioned to provide stiffness where needed. The composite cover plates are attached to specific locations on the frame to reinforce areas subject to higher loads, optimizing stiffness distribution throughout the door structure.
4Strength
If complex web structures are used in composite doors to ensure stiffness, then structural strength is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the functions of the composite web parts with the composite frame structure. The web parts are integrated into the frame design, connecting side beams and serving as mounting structures for cover plates, thereby reducing the number of separate components and simplifying manufacturing while maintaining structural strength.
Solution Approach 2:
The composite web parts perform multiple functions: they provide structural stiffness, connect side beams, and serve as mounting structures for composite cover plates. This multi-functionality reduces the overall complexity of the door structure by eliminating the need for separate mounting brackets and reinforcement elements.
Data Source
Figure 1~2
Figure 3a~3b
Figure 4a~4b
AI summary
The present disclosure relates to a door (100) for an aircraft (1). The door comprises an outer skin (110), a plurality of outer blades (120, 130) extending from the outer skin (110) at a predefined angle, a plurality of inner blades (220, 230), and an inner skin (210) attached to the plurality of inner blades, wherein the inner skin comprises a plurality of sections, each extending at a predefined angle from one of the plurality of inner blades. The outer skin, the plurality of outer blades, the plurality of inner blades, and the inner skin are made from a composite plastic material, and each of the plurality of inner blades is attached to one of the plurality of outer blades.