Lightning-Resistant Fastener With Integrated Insulating Section
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Solution Overview
Problem
Existing lightning-resistant fastener systems for aircraft wings are inefficient and costly due to manual installation requirements, potential misalignment issues, and variability in work quality, leading to suboptimal insulation performance and reliability concerns.
Innovation Solution
A lightning-resistant fastener design featuring a fastener main body with an insulating section, such as an insulating coat film or collar, that increases electrical resistance between the fastener and structural members, directing lightning currents along the wing panel, thereby reducing arc discharge risks and eliminating the need for manual sealing or cap installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cap is installed separately from the fastener main body with an air-gap to provide insulation, then lightning resistance performance is improved, but installation precision deteriorates due to misalignment between cap and fastener member centers
Solution Approach 1:
The insulating section is integrated directly into the fastener main body structure, merging the fastening function and insulation function into a single component. This eliminates the separate cap installation process and ensures precise alignment between the insulating section and the fastener member without requiring additional alignment operations.
Solution Approach 2:
The fastener main body provides its own insulation function through the integrated insulating section, eliminating the need for separate insulation components. The insulating section is automatically positioned correctly as part of the fastener assembly process, making the system self-aligning and self-sufficient for insulation requirements.
2Reliability
If a cap is installed separately requiring adhesive or rubber coating, then insulation function is achieved, but work time and labor increase significantly
Solution Approach 1:
The insulating section is manufactured as an integrated part of the fastener main body, combining the fastening component and insulation component into one piece. This eliminates the need for separate cap installation, adhesive application, or rubber coating operations, dramatically reducing installation time and labor requirements.
Solution Approach 2:
The fastener main body inherently provides insulation through its integrated insulating section, eliminating the need for additional insulation materials or processes. The single-component design performs both fastening and insulation functions simultaneously without requiring separate operational steps.
3Reliability
If manual installation of caps and sealing work is performed, then insulation is achieved, but work quality varies depending on worker skill level
Solution Approach 1:
The insulating section is integrated into the fastener main body as a single manufactured component, ensuring consistent insulation quality through controlled manufacturing processes rather than variable manual installation. This eliminates skill-dependent quality variations associated with manual cap installation and sealing operations.
Solution Approach 2:
The fastener assembly provides consistent insulation performance through its integrated insulating section, eliminating variability introduced by different workers' skills. The insulation function is built-in and automatically performed correctly every time the fastener is installed, ensuring uniform quality across all installations.
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 enhances lightning resistance performance while reducing costs and improving field work efficiency and reliability by ensuring most lightning currents flow along the wing panel, minimizing arc discharge occurrences, and maintaining high reliability without requiring complex site-specific work.
Implementation Method 1
an insulating section made of an insulative material and formed between a portion opposed to the second hole in the fastener main body and the second hole to be continuous in the entire circumferential direction
Data Source
AI summary
There is provided a lightning-resistant fastener that can secure sufficient lightning-resistance performance at low cost and realize efficiency of field work and improvement of reliability. An insulating coat film 40 is formed in a region opposed to a structural member 22 in a shaft section 25c of a fastener main body 25 and an insulating layer is interposed between the structural member 22 and the shaft section 25c of the fastener main body 25, whereby an electric current is fed along a head section 25b side of the fastener main body 25 and a wing panel 21 when lightning occurs. This suppresses the electric current from flowing to the front end portion side of the fastener main body 25, i.e., the interior side of a wing 20 and prevents arc discharge from occurring inside the wing 20.