Hat-stringer assembly with integrated fitting for aircraft fuel tanks
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Solution Overview
Problem
The assembly of fittings and valves onto hat stringers in aircraft fuel tanks is time-consuming and adds weight due to the need for separate fastening and shimming, which complicates the process and increases the overall weight of the aircraft.
Innovation Solution
A hat-stringer assembly that integrates a fitting with the hat stringer, formed from composite materials, which eliminates the need for separate assembly and fastening, enhancing local stiffness while reducing weight by co-curing or co-bonding the components together.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fittings and valves are assembled separately onto hat stringers, then the assembly process requires additional fastening, drilling, shimming, and sealing operations, but this increases assembly time and adds weight to the aircraft
Solution Approach 1:
The patent integrates the fitting directly into the hat stringer structure by forming the fitting as an integral part of the hat stringer during the same manufacturing process. This merging eliminates the need for separate assembly operations including fastening, drilling, shimming, and sealing, thereby reducing assembly time and simplifying the manufacturing process
2Reliability
If separate fasteners and shims are used to attach fittings to hat stringers, then the attachment is secured, but this adds weight to the aircraft assembly
Solution Approach 1:
The fitting is formed as an integral part of the hat stringer structure, eliminating the need for separate fasteners and shims. This integration maintains attachment security while removing the additional weight that would be introduced by separate fastening components
3Adaptability or versatility
If fittings are assembled onto completed hat stringers, then the components can be attached after stringer formation, but this requires additional assembly operations for fastening and sealing
Solution Approach 1:
The fitting and hat stringer are formed as a single integrated component in one manufacturing process, eliminating the need for subsequent assembly operations. This integration reduces device complexity by removing multiple assembly steps while maintaining the functional adaptability of the venting system
Data Source
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AI summary
A hat-stringer assembly (100) for an aircraft (500) comprises a hat stringer (110) with a first hat-stringer leg (140), a second hat-stringer leg (150), a first hat-stringer sidewall (114), a connecting wall (112), a second hat-stringer sidewall (116), and a ventilation opening (128), extending through the connecting wall (112). The hat stringer assembly (100) also comprises a fitting (200), comprising a first channel member (210) in contact with the first hat-stringer sidewall (114) and the first hat-stringer leg (140). The fitting (200) also comprises a second channel member (240) in contact with the second hat-stringer sidewall (116) and the second hat-stringer leg (150). The fitting (200) further comprises a web cap (260), in contact with the first channel member (210) and the second channel member (240). The web cap (260) comprises a web-cap opening (262), which is in fluidic communication with the ventilation opening (128).