Fold Wing Tip Stub Spar Load Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing folding wing designs for commercial aircraft are weight-intensive due to large hinges and locking pins required to handle high reaction loads, which negates the aerodynamic efficiency gains from long high aspect ratio wings, and are not optimized for commercial aircraft mission parameters.
Innovation Solution
A wing design featuring a wing tip hinged to a main section with a stub spar that extends past the tip end, allowing the stub spar to react moment loads across its length, thereby reducing the load on hinges and locking pins, enabling smaller, lighter components and maintaining aerodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the size of hinges and locking pins is increased to handle high reaction loads, then the structural strength is improved, but the aircraft weight increases
Solution Approach 1:
The stub spar extends the moment arm in a new dimensional direction (perpendicular to the wing surface), transitioning from a two-dimensional hinge connection to a three-dimensional load distribution system. This allows the moment load to be reacted over a longer distance through the stub spar extension, reducing the force requirements at the hinge and locking pin interfaces while maintaining structural strength.
2Use of energy by moving object
If the wing span is extended to achieve high aspect ratio, then the aerodynamic efficiency is improved, but the airport infrastructure compatibility deteriorates
Solution Approach 1:
The wing tip is designed with folding capability, transforming from a static fixed-span structure to a dynamic adjustable-span structure. The wing tip can be folded to a vertical position above the fuselage for storage and transport through airport infrastructure, then extended to the full high aspect ratio configuration for aerodynamically efficient flight operations.
3Weight of moving object
If the hinges and locking pins are made smaller to reduce weight, then the aircraft weight is reduced, but the load-bearing capacity deteriorates
Solution Approach 1:
The stub spar acts as an intermediary structural element that mediates the load transfer between the wing tip and the main wing section. By providing an extended moment arm through the stub spar, the system distributes and reduces the reaction loads transmitted to the hinges and locking pins, allowing these components to be smaller and lighter while maintaining adequate load-bearing capacity.
Data Source
AI summary
A wing includes a wing tip hinged to a main wing section. The wing tip includes a stub spar extending past an end of the wing tip. When the wing tip is extended, the stub spar extends into the main wing section to react a moment load across a length of the stub spar.