Composite Stringer Skin Structure Fiber Orientation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stringer and skin structures in aircraft are costly to fabricate and do not offer a favorable strength-to-weight ratio compared to conventional structures.
Innovation Solution
A composite stringer and skin structure fabricated using reinforced polymer-based materials with multiple layers of oriented reinforcing fibers, where the stringer includes a web portion and flange portions formed from cured and uncured components bonded with a film adhesive, and the skin is coupled to the flange using fasteners that provide compressive force and reinforce the adhesive bond.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If reinforced polymer-based materials are used to form structural members as a substitute for metals, then weight is reduced and strength-to-weight ratio is improved, but manufacturing cost and fabrication complexity increase
Solution Approach 1:
The stringer is divided into multiple discrete plies or layers, each with specific fiber orientations (0°, 45°, -45°, 90°). This segmentation allows for optimized structural performance while enabling modular manufacturing and assembly processes, reducing overall fabrication complexity.
Solution Approach 2:
The patent employs composite materials consisting of reinforcing fibers embedded in a polymer matrix. This composite structure provides high strength-to-weight ratio while allowing tailoring of mechanical properties through fiber orientation and layer configuration, addressing both weight reduction and performance requirements.
2Strength
If multiple layers of reinforcing fibers are used in the stringer structure, then mechanical strength and stiffness are improved, but manufacturing complexity and fabrication difficulty increase
Solution Approach 1:
The stringer is segmented into multiple plies with distinct fiber orientations arranged in a specific sequence. This segmentation enables optimization of mechanical properties in different directions while facilitating step-by-step manufacturing processes, reducing overall fabrication difficulty.
Solution Approach 2:
Different plies have different fiber orientations (0°, 45°, -45°, 90°) tailored to specific loading conditions. This local quality variation optimizes strength and stiffness where needed while simplifying the overall manufacturing approach by addressing specific structural requirements in each layer.
3Force
If the stringer web portion is oriented perpendicular to the skin member, then resistance to bending moment is improved, but susceptibility to lateral buckling increases
Solution Approach 1:
The stringer is constructed as a composite material structure with multiple plies of fiber-reinforced polymer. This composite construction provides high strength-to-weight ratio while allowing tailoring of mechanical properties through fiber orientation and layer configuration, addressing both bending resistance and buckling prevention.
Solution Approach 2:
The stringer web is segmented into multiple plies with specific fiber orientations that provide resistance to both bending moments and lateral buckling. This segmentation allows optimization of structural performance for multiple loading conditions simultaneously.
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 provides a more cost-effective and lightweight structural component with improved strength-to-weight ratio, suitable for aircraft applications, by utilizing interleaved fiber orientations and suitable adhesives and fastening systems to enhance bonding and structural integrity.
Implementation Method 1
bonded with a film adhesive
Implementation Method 2
fasteners that provide compressive force and reinforce the adhesive bond
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A composite stringer and skin structure (10) includes a polymer-based elongated stringer (12) having reinforcing fibers positioned in a plurality of adjacent plies, plies (52, 58) of the reinforcing fibers being oriented at a relatively shallow angle relative to a selected reference direction, and plies (62, 66) of the reinforcing fibers being oriented at a relatively broad angle relative to the selected reference direction. A polymer-based and fiber reinforced skin member (20) adjoins the stringer and an adhesive material ( is interposed between the stringer portion and the skin member.