Shear-Loaded Wing-to-Fuselage Attachment Assembly
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Solution Overview
Problem
Current wing-to-body attachment methods in aircraft require large and heavy fasteners to handle tensile loads, increasing the weight and complexity of the attachment assemblies during wing loading conditions.
Innovation Solution
An attachment assembly that loads fasteners in shear instead of tension, using a first attachment member connected to the aircraft body and a second attachment member connected to the wing box, with a bearing plate positioned between them to reduce shear load and allow for smaller, lighter fasteners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fasteners are designed to carry tensile loads during wing loading conditions, then the attachment assembly can safely handle the loads, but the fasteners become relatively large and increase the weight of the attachment assembly
Solution Approach 1:
The patent changes the loading parameter of the fasteners from tension to shear by modifying the attachment assembly configuration. The engagement member and extension tab are positioned and oriented such that wing loading conditions produce shear forces on the fasteners rather than tensile forces, allowing the use of smaller, lighter fasteners while maintaining load carrying capability
Solution Approach 2:
Instead of designing fasteners to resist tensile loads directly, the patent inverts the approach by configuring the attachment members to convert the loading condition into shear. This inversion of the load path allows for more efficient fastener utilization and reduced weight
2Reliability
If multiple attachment assemblies with fasteners are used to join the wing assembly to the aircraft body, then the wing can be securely attached, but the assembly process becomes time-consuming and complex
Solution Approach 1:
The attachment system is segmented into modular components: a first attachment member coupled to the aircraft body, a second attachment member coupled to the wing box, and fasteners that join them. This segmentation allows for pre-assembly and modular installation, reducing overall assembly time while maintaining secure attachment through multiple connection points
3Reliability
If large fasteners are used to carry tensile loads, then the attachment assembly can handle wing loading conditions, but the device complexity increases
Solution Approach 1:
By changing the parameter of fastener loading from tension to shear through configuration of the engagement member and extension tab, the patent enables the use of simpler, smaller fasteners that require less material and structural complexity while maintaining the required load carrying capability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution reduces the weight and complexity of the attachment assemblies by using smaller, lighter fasteners that are loaded in shear during wing loading conditions, while maintaining structural integrity through the high shear strength of the fasteners and the compression force from the bearing plate.
Implementation Method 1
the bearing plate is configured to engage the distal end of the outer flange during the wing loading condition
Data Source
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AI summary
An aircraft (10) includes an aircraft body (30) including a longitudinal axis (31) and a wing box (40) extending through the aircraft body. The aircraft also includes an attachment assembly (100) coupled to the aircraft body and to the wing box. The attachment assembly includes a first attachment member (102) coupled to the aircraft body and a second attachment member (104) coupled to the wing box. The second attachment member is configured to couple to the first attachment member. The attachment assembly also includes a plurality of fasteners (106) extending through the first attachment member and the second attachment member such that the plurality of fasteners are loaded in shear during a wing loading condition.