Hat Stringer Repair Using Partial Profile-Matched Reinforcement
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Solution Overview
Problem
Conventional techniques for repairing damaged hat stringers in aircraft structures present challenges, particularly in terms of matching the internal profile of the repair stringer to the hat stringer and ensuring adequate structural reinforcement.
Innovation Solution
A method of repairing a hat stringer by arranging a repair stringer in a mounting location along its cross section, where the internal profile of the repair stringer matches the internal cavity profile of the hat stringer, and coupling the repair stringer with a stringer of the hat stringer. The repair stringer has a partial cross-sectional area compared to the hat stringer, allowing for flexible mounting in multiple locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a repair stringer with full cross-sectional area is used to replace a damaged hat stringer, then structural strength is improved, but weight and material usage increase significantly
Solution Approach 1:
The patent applies partial action by using a repair stringer with partial cross-sectional area rather than full area. The repair stringer is designed to provide only the necessary structural reinforcement needed for the damaged area, not complete replacement. This reduces material usage and weight while maintaining adequate structural strength through strategic placement and profile matching with the hat stringer cavity.
2Manufacturing precision
If a repair stringer with custom unique profile is fabricated to match the hat stringer cavity, then manufacturing precision is improved, but device complexity and fabrication difficulty increase
Solution Approach 1:
The patent applies universality by designing a repair stringer with a standardized profile that can be used across multiple mounting locations and different hat stringer configurations. Rather than creating unique custom profiles for each repair scenario, the universal profile can be adapted to various positions (e.g., different sides of the hat stringer, different mounting locations along the span) through orientation changes, reducing fabrication complexity while maintaining adequate profile matching.
3Strength
If multiple repair stringers are stacked to reconstruct a full cross-section, then structural strength is improved, but device complexity and assembly difficulty increase
Solution Approach 1:
The patent applies partial action by determining that full cross-sectional reconstruction through stacking multiple repair stringers is not necessary. Instead, a single repair stringer with partial cross-sectional area provides sufficient structural reinforcement for the damaged region. This avoids the complexity of stacking, aligning, and assembling multiple components while achieving the required strength through optimized partial replacement.
Data Source
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AI summary
The present disclosure provides a method (700) of repairing a hat stringer (200). The method includes arranging (702) a repair stringer (300, 400) in a mounting location that is one of a plurality of possible mounting locations along a cross section of a hat stringer. In each of the plurality of possible mounting locations, at least a portion of an internal profile (308) of the repair stringer matches at least a portion of a profile (224) of an internal cavity (222) defined by the hat stringer. A cross-sectional area of the repair stringer as viewed along a first direction (D1) is less than a total cross-sectional area of the hat stringer as viewed along the first direction. The method also includes coupling the repair stringer with a stringer (210) of the hat stringer in the mounting location. Repair stringers and repaired hat stringers are also provided.