Stiffened Composite Panel With Integrated Trimmed Shim
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Solution Overview
Problem
The assembly of aircraft requires precise fitting of panels to internal structures, which is labor-intensive and time-consuming due to non-uniform gaps that need custom shims, causing delays and inefficiencies in the manufacturing process.
Innovation Solution
The use of stiffened composite panels with an integrated shim made of sacrificial material, such as glass fiber reinforced plastic, that can be trimmed to fit specific dimensions and measurements, eliminating the need for separate shims and reducing labor and assembly time by allowing precise fitting before installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If custom shims are manufactured separately to fit non-uniform gaps, then precise fitting is achieved, but labor intensity and assembly time increase significantly
Solution Approach 1:
The shim is merged with the stringer to form an integrated assembly. The shim material is positioned between the stringer flange and skin during composite layup, and all components are co-cured as a single unit. This eliminates the need for separate shim manufacturing and assembly operations, resolving the contradiction by achieving both precise fitting (through integrated design) and high productivity (through reduced assembly steps).
Solution Approach 2:
The shim is pre-positioned and integrated into the stringer assembly during the composite panel manufacturing process, before final installation. By incorporating the shim into the stringer flange structure during co-curing, the fitting precision is ensured in advance, and no additional shim installation steps are required during aircraft assembly, thereby improving productivity.
2Manufacturing precision
If separate custom shims are manufactured and installed, then gap filling is achieved, but the number of parts and assembly steps increases
Solution Approach 1:
The shim and stringer are merged into a single integrated component. The shim material is embedded within the stringer flange structure during composite layup, reducing the component count from two separate parts (stringer and shim) to one integrated assembly. This maintains gap fitting accuracy while simplifying the overall structure and reducing assembly complexity.
3Adaptability or versatility
If multiple separate components (stringer and shim) are assembled, then structural flexibility is maintained, but assembly variability increases
Solution Approach 1:
The stringer and shim are co-cured as a single integrated composite structure, eliminating variability introduced by separate assembly operations. The integrated design ensures consistent positioning and fitment while maintaining the structural adaptability needed for different aircraft configurations through design flexibility rather than assembly variability.
4Ease of operation
If traditional separate shim assembly is used, then ease of replacement is maintained, but labor costs and time consumption increase
Solution Approach 1:
The integrated stringer-shim assembly reduces assembly time by eliminating separate shim installation steps. The shim is pre-integrated into the stringer flange during composite manufacturing, so no additional assembly operations are required during aircraft assembly, directly addressing the time loss issue while maintaining operational efficiency.
Data Source
AI summary
Provided are stiffened stringer panels with integrated shim structures. An example composite panel comprises a skin member having an inner surface, and a stringer positioned on the inner surface. The stringer comprises a first flange portion and a second flange portion with the first flange portion and the second flange portion contacting the inner surface. The composite panel further comprises an integrated shim positioned on the first flange portion. The integrated shim may comprise a sacrificial material configured to be trimmed to the desired geometry. The sacrificial material may comprise a glass fiber reinforced plastic fabric pre-impregnated with resin. The integrated shim may be configured to interface with internal support structures of a wing assembly. The integrated shim may be configured to be machined to fit dimensions and measurements corresponding to the internal support structures of the wing assembly.