Wing Tip Joint Clevis Lug Fastening System
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Solution Overview
Problem
Current wing tip joints in aircraft are impractical for interchangeability and performance due to limitations in load transfer and physical space constraints, particularly with shear joints, tension joints, and pinned joints, which restrict the ability to carry wing bending loads effectively.
Innovation Solution
A clevis and lug fastening system is implemented with a hinge unit located between the upper and lower aerodynamic surfaces, allowing for a moment reaction and improved load distribution, enabling the wing tip to be securely attached and detached while maintaining aerodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional shear joints, tension joints, or pin joints are used to attach wing tips, then the wing tip can be made removable and replaceable, but the ability to effectively carry wing bending loads is restricted due to physical space constraints and impracticality for interchangeability
Solution Approach 1:
The hinge unit is positioned at a location that is offset from both the upper and lower aerodynamic surfaces, creating a third dimensional arrangement rather than traditional top-bottom fastening. This intermediate positioning allows the hinge to effectively transfer bending loads while maintaining removability, as the moment reaction is distributed through the wing structure rather than concentrated at the extreme surfaces.
Solution Approach 2:
The hinge unit acts as an intermediary component between the wing tip and the wing structure. It provides a dedicated load transfer path that mediates between the removable connection requirement and the strength requirement, allowing the wing tip to be attached and detached while effectively carrying bending loads through the intermediate hinge position.
2Loss of energy
If the airfoil thickness is reduced to decrease aerodynamic drag, then aerodynamic performance is improved, but the amount of room available for structural components within the airfoil is reduced
Solution Approach 1:
Instead of positioning structural components only at the traditional upper and lower surfaces of the thin airfoil, the hinge unit is positioned at an intermediate location offset from both surfaces. This dimensional repositioning allows the structural component to fit within the limited thickness of the airfoil while still providing effective load transfer, thus maintaining low drag with sufficient structural space.
3Strength
If multiple fasteners are used in shear joints or tension bolts in tension joints, then the wing tip can be securely attached, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The invention extracts the fastening function from the traditional multiple-fastener configuration and consolidates it into a single hinge unit. By positioning the hinge at an intermediate location, the design eliminates the need for multiple fasteners distributed across the upper and lower surfaces, reducing joint complexity while maintaining secure attachment through the moment reaction mechanism.
Data Source
AI summary
An aircraft joint comprises a wing structure and a wing tip. The wing structure has a first part of a clevis and lug fastening system located around an outer end of the wing structure. The wing tip has a second part of the clevis and lug fastening system located around an end of the wing tip. The wing tip is capable of being joined to the outer end of the wing structure. An upper aerodynamic surface and a lower aerodynamic surface are formed by joining the wing structure and the wing tip. The first part and the second part are located about a center between the upper aerodynamic surface and the lower aerodynamic surface. The first part and the second part engage each other such that a moment reaction occurs around the upper aerodynamic surface and the lower aerodynamic surface.