Composite Fuselage Local Reinforcements for Stiffness and Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional metallic aircraft fuselages are heavy and labor-intensive to manufacture, and composite fuselages with lattice-type backing structures are complex and not optimally designed for load distribution, requiring many stiffeners and complex production processes.
Innovation Solution
A fibre-reinforced composite aircraft fuselage with a skin and backing structure where local reinforcements on the skin manage shear loads and internal pressure, reducing the number of longitudinal stiffeners, allowing the skin to be flexible and optimized for shear loads, while circumferential stiffeners handle circumferential loads and moments, with fewer longitudinal stiffeners required due to increased local stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a lattice-type backing structure with many stiffeners is used, then the skin is adequately stiffened, but the production complexity increases significantly
Solution Approach 1:
The patent applies local quality by implementing local reinforcements at specific positions on the skin rather than a uniform lattice structure. These local reinforcements are strategically placed to provide stiffness exactly where needed, eliminating the need for a comprehensive lattice of stiffeners throughout the entire skin surface. This approach maintains adequate skin stiffness while dramatically reducing production complexity.
2Reliability
If many longitudinal stiffeners are used, then the fuselage maintains structural stability, but the weight increases
Solution Approach 1:
The patent reduces weight by replacing numerous longitudinal stiffeners with localized reinforcements positioned only where structural stability is required. This selective approach maintains fuselage stability under normal operating conditions while eliminating the excess weight of unnecessary stiffeners throughout the fuselage.
Solution Approach 2:
The patent segments the longitudinal stiffening function into discrete local reinforcements rather than continuous longitudinal stiffeners. This segmentation allows the structure to maintain stability where needed while removing material and weight from regions where full longitudinal stiffening is not required.
3Strength
If the skin is made stiff in the longitudinal direction, then longitudinal loads are better supported, but pressure bulges occur earlier
Solution Approach 1:
The patent resolves this contradiction by providing longitudinal stiffness only at local reinforcement positions rather than making the entire skin stiff in the longitudinal direction. This allows the skin to remain flexible and resistant to pressure bulges between reinforcements, while still adequately supporting longitudinal loads at the reinforced locations.
Data Source
AI summary
A fuselage of a fiber-reinforced composite material for an aircraft with a skin and with a multiplicity of circumferential stiffeners and only a small number of longitudinal stiffeners, the skin having a multiplicity of local reinforcements.