3D Woven Fibrous Reinforcement for Composite Articulation Ends
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Solution Overview
Problem
Existing composite materials for aircraft parts, such as landing gear struts, suffer from increased stress concentration, delamination risk, high manual labor requirements, and suboptimal mechanical performance, particularly in compressive strength, leading to inefficiencies in mass savings and integration.
Innovation Solution
A fibrous preform with a core-belt assembly design using three-dimensional weaving, featuring varying yarn ratios and thicknesses at articulation ends to enhance mechanical performance and reduce manual labor, while maintaining a consistent number of layers and minimizing non-conformities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a laminated structure with intercalation of plies is used to form articulation forks, then the risk of delamination is reduced, but the size of stress introduction areas increases and mass saving is compromised
Solution Approach 1:
The patent uses a three-dimensional woven composite structure instead of a laminated structure. The 3D weaving creates interlaced yarns that extend in multiple directions (longitudinal, transverse, and diagonal), forming a monolithic structure that resists delamination without requiring increased ply intercalation. This maintains smaller stress introduction area sizes while ensuring structural reliability.
Solution Approach 2:
The patent transitions from a two-dimensional laminated structure to a three-dimensional woven structure. The yarns are arranged in three dimensions with longitudinal yarns extending along the length, transverse yarns crossing perpendicular to the longitudinal direction, and diagonal yarns providing additional reinforcement. This 3D arrangement creates inherent resistance to delamination through spatial interlacing rather than through increased lamination thickness.
2Manufacturing precision
If manual work is increased to achieve precise fiber placement, then manufacturing precision improves, but production cost and time increase
Solution Approach 1:
The patent changes the manufacturing approach from manual fiber placement to automated 3D weaving. By adjusting weaving parameters such as yarn density, weave pattern, and tension during the weaving process, the desired fiber distribution and structural properties are achieved automatically. This eliminates manual intervention while maintaining precise fiber placement through controlled mechanical weaving operations.
Solution Approach 2:
The patent replaces manual mechanical fiber placement operations with an automated 3D weaving mechanical system. The weaving machine uses programmed motion control to guide yarns through complex three-dimensional paths, automatically creating the desired reinforcement structure. This substitution of manual labor with automated machinery improves both precision and productivity simultaneously.
3Strength
If material is added in the common area to improve compressive strength, then mechanical performance improves, but mass increases
Solution Approach 1:
The patent applies different yarn densities and configurations in different regions of the structure. In the common area subjected to compressive loads, the 3D weaving pattern is optimized with appropriate yarn spacing and tension to provide sufficient compressive strength. In articulation areas, the yarn arrangement is adjusted to handle bending and shear stresses. This localized optimization ensures adequate strength throughout without adding unnecessary material mass.
Solution Approach 2:
The patent utilizes the inherent properties of three-dimensional woven composite materials to achieve efficient load distribution. The interlaced yarn structure in three dimensions provides multi-directional reinforcement that resists compressive, tensile, and shear stresses simultaneously. This composite structure delivers the required compressive strength in the common area without requiring additional material layers, thereby avoiding mass increase.
Data Source
AI summary
A fibrous preform of a core portion of a fibrous reinforcement for a composite material part, the preform having an elongate shape along a longitudinal direction and being formed by three-dimensional weaving of first yarns extending along the longitudinal direction with second yarns transverse to the first yarns, the preform including two longitudinal ends for articulation with other parts and a median area located between the longitudinal ends, each longitudinal end having a thickness greater than a thickness of the median area, the median area having a first volume ratio of first yarns to second yarns that is greater than one, and each longitudinal end having a second volume ratio of first yarns to second yarns that is less than the first ratio and closer to one than this first ratio.