Braced Wing Aircraft Staggered Spar Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional braced wing aircraft configurations with box-wing or joined-wing designs face challenges in achieving efficient load continuity and integration of propulsion units, leading to increased complexity, weight, and limited practical applications due to structural kinks and inefficiencies in load path support.
Innovation Solution
A braced wing aircraft design featuring staggered and interconnected dependent singular wings with a specific structural arrangement where upper and lower wing spars are connected through transition spars in a virtually spanned plane, eliminating kinks and enhancing stiffness, allowing for improved support of propulsion devices without additional ribs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional box-wing or joined-wing configurations are used with upper and lower wings formed on the basis of conventional staggered braced wing configurations, then the basic wing structure is achieved, but plural kinks are formed in associated wing spars at the area of respective wing tips leading to increased constructional complexity
Solution Approach 1:
The wing structure is divided into upper and lower wings that are staggered and interconnected at transition regions. Each wing has its own spars (upper wing spars and lower wing spars) that are connected through transition spars, creating modular segments that reduce overall constructional complexity while maintaining the box-wing configuration.
Solution Approach 2:
Transition spars are introduced as intermediary elements connecting the upper wing spars to the lower wing spars at the transition regions. These transition spars act as mediators that enable efficient load transfer between the upper and lower wings without creating kinks in the main spars, thereby reducing constructional complexity.
2Strength
If additional ribs are added to support kinks in wing spars, then the required stiffness and strength are guaranteed, but additional weight, cost, fatigue sensitivity, and complexity increase
Solution Approach 1:
The transition spars are arranged in a virtually spanned plane that ensures continuous load transfer from the upper wings to the lower wings. This continuous load path eliminates the need for additional ribs to support kinks, maintaining wing strength while reducing structural complexity and weight.
Solution Approach 2:
The arrangement of spars in a virtually spanned plane changes the geometric parameters of the wing structure. By optimizing the spatial arrangement and inclination of spars, the structure achieves required stiffness and strength through geometric optimization rather than adding more structural elements.
3Adaptability or versatility
If propeller or engine is mounted at the respective wing tips in the wing interconnection region, then propulsion is integrated into the wing structure, but the main load path becomes comparatively inefficient due to interface areas and cut of main load carrying members
Solution Approach 1:
The transition spars serve multiple functions: they connect the upper and lower wings structurally, transfer loads between them, and provide mounting support for propulsion units at the wing tips. This multi-functionality allows propulsion integration without compromising load path efficiency.
Solution Approach 2:
The transition spar arrangement creates a redundant load path that can accommodate propulsion units. The virtually spanned plane of spars provides a copied or alternative load transfer route that maintains efficiency even when propulsion units are mounted at the wing tips, preventing disruption of the main load path.
4Adaptability or versatility
If the spars of upper and lower wings are arranged to provide support for propeller or engine, then propulsion support is enabled, but the wing stiffness is reduced due to interface areas and cuts in main load carrying members
Solution Approach 1:
The spars are arranged in a virtually spanned plane that is inclined with respect to the vertical aircraft axis, introducing a new spatial dimension to the structure. This three-dimensional arrangement allows the spars to provide propulsion support while maintaining wing stiffness through optimized geometric configuration rather than relying on traditional two-dimensional wing box structures.
Data Source
AI summary
A braced wing aircraft with a fuselage and a fixed wing arrangement, the fixed wing arrangement comprising at least two braced wings that are arranged laterally and opposite to each other on the fuselage, each one of the at least two braced wings comprising at least one upper wing and at least one lower wing which are staggered and interconnected at a predetermined transition region, the at least one upper wing being connected to the fuselage at an associated upper wing root and the at least one lower wing being connected to the fuselage at an associated lower wing root.