Automated I-Stringer Manufacturing Using Cap Forming and Flexible Mandrel
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Solution Overview
Problem
The manual manufacture of aircraft stringers from fiber reinforced composite materials is time-consuming, costly, and prone to defects, making it inefficient and non-conformative for large-scale production.
Innovation Solution
A method involving a cap-forming device and a flexible mandrel is used to automate the production of reinforced composite structures, where composite material plies are overlapped and pre-cured cap inserts are positioned to form a preformed cap section, which is then cured under heat and pressure to create a reinforced composite structure affixed to a skin structure, utilizing a cap-forming device and flexible mandrel to streamline the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual methods are used to manufacture fiber reinforced composite stringers, then flexibility and adaptability are maintained, but productivity is low and manufacturing time is excessive
Solution Approach 1:
The stringer manufacturing process is divided into distinct segments: cap section formation using a cap-forming device, web section formation using a flexible mandrel, and foot section attachment to the skin structure. This segmentation allows each segment to be manufactured and cured separately, then assembled into the final stringer, significantly increasing productivity while maintaining quality control.
Solution Approach 2:
The cap section is pre-formed and pre-cured using the cap-forming device before being integrated into the full stringer assembly. This preliminary action allows the cap section to be prepared in advance, reducing overall manufacturing time and enabling parallel processing of different stringer components.
2Manufacturing precision
If manual manufacturing methods are used, then device complexity is low, but manufacturing precision and reliability are compromised due to defects and non-conformities
Solution Approach 1:
The flexible mandrel serves as an intermediary tool that enables precise formation of the web section and foot portions of the stringer. The mandrel provides a controlled environment for curing the composite material, ensuring consistent dimensions and proper alignment, thereby improving manufacturing precision despite the added equipment complexity.
3Loss of time
If hand manufacture is used for extensive stringer networks in aircraft, then adaptability to design changes is maintained, but loss of time and manufacturing cost become prohibitive
Solution Approach 1:
The manufacturing process enables continuous production through automated material layup and curing operations. The cap-forming device and flexible mandrel system allows for uninterrupted formation and curing of stringer sections, eliminating the interruptions inherent in manual manufacturing and significantly reducing total manufacturing time for extensive stringer networks.
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
This method significantly increases output, reduces defects, and enables efficient, continuous production of reinforced composite structures for aircraft, improving the rigidity and support of stringers while minimizing manual errors.
Implementation Method 1
The composite material layout is heated and pressurized using the flexible mandrel to cure the composite material layout and form the reinforced composite structure affixed to the skin structure
Implementation Method 2
The composite material layout is heated and pressurized using the flexible mandrel to cure the composite material layout and form the reinforced composite structure affixed to the skin structure
Data Source
AI summary
Methods for manufacturing a reinforced composite structure for an aircraft and devices used in such methods are provided. A device includes a base, a first support member fixedly attached to the base, and a second support member fixedly attached to the base and aligned longitudinally with the first support member. The first support member and the second support member are spaced a first distance apart. Two pinching wheels are spaced a second distance apart. The two pinching wheels are positioned proximate to ends of the first support member and the second support member. The second distance is less than the first distance. The two pinching wheels are configured to receive a composite material layout between them and to cause two lengths of the composite material layout to contact each other.