Selective Needling of Fibrous Preforms for Complex Contours
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fiber-reinforced composite structures face challenges in managing varying in-plane and interlaminar stresses, particularly during the manufacturing process of complex contour parts, leading to issues like fiber nonuniformities, wrinkling, and breakage.
Innovation Solution
A method for selective needling of fibrous preforms is introduced, where needle density, angle, and penetrating depth are varied based on interlaminar stress zones to enhance through-thickness reinforcement, allowing for efficient shaping into complex contours while minimizing fiber sliding and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If uniform needling is applied across the entire fibrous preform, then through-thickness reinforcement is provided, but fiber nonuniformities, wrinkling, and breakage occur due to varying interlaminar stress requirements across different zones
Solution Approach 1:
The patent applies different needling parameters (needle density, angle, penetrating depth) to different zones of the fibrous preform based on local interlaminar stress requirements. High-interlaminar-stress zones receive higher needle density and greater penetrating depth, while low-interlaminar-stress zones receive reduced needling, thereby providing locally optimized reinforcement without causing fiber nonuniformities or damage.
Solution Approach 2:
The patent varies multiple needling parameters including needle density, needle angle, and penetrating depth across different zones of the preform. These parameter changes allow the needling process to adapt to varying interlaminar stress conditions, improving interlaminar strength where needed while preserving fiber integrity in regions requiring less reinforcement.
2Strength
If high needle density is used to reinforce high interlaminar stress zones, then interlaminar strength is improved, but fiber sliding and damage increase in those zones
Solution Approach 1:
The patent implements zone-specific needling where high needle density and greater penetrating depth are applied only to high interlaminar stress zones that require additional reinforcement, while low interlaminar stress zones receive reduced or no needling. This localized approach ensures that fiber damage is minimized in regions where it is not necessary, while still providing the required interlaminar strength in critical areas.
Solution Approach 2:
The patent applies needling at varying intensities across different zones, using partial action (reduced needling) in low-stress zones and excessive action (higher needling) only where required by interlaminar stress conditions. This prevents unnecessary fiber damage in regions that do not require strong through-thickness reinforcement.
3Manufacturing precision
If selective needling with varying parameters is applied, then fiber integrity is maintained, but the complexity of the needling process increases
Solution Approach 1:
The patent divides the fibrous preform into multiple zones based on interlaminar stress distribution, with each zone assigned specific needling parameters. This segmentation allows the complex needling process to be broken down into manageable zone-specific operations, making the process controllable and implementable through programmable needle arrays or robotic systems.
Solution Approach 2:
The patent employs dynamic adjustment of needling parameters (density, angle, penetrating depth) based on the spatial location and stress characteristics of different zones. This dynamic approach allows the needling system to adapt to varying requirements across the preform, maintaining fiber integrity through intelligent parameter variation rather than fixed uniform needling.
Data Source
AI summary
A method for selective needling on a fibrous preform includes performing a through thickness reinforcement process on the fibrous preform and varying a needle density, a needle angle, and/or a needle penetrating depth during the through thickness reinforcement process such that a first needle density, a first needle angle, and/or a first needle penetrating depth of a first zone of the fibrous preform is greater than a second needle density, a second needle angle, and/or a second needle penetrating depth of a second zone of the fibrous preform. The method can further include identifying expected interlaminar stress throughout the fibrous preform and varying the needle density, needle angle, and/or needle penetrating depth in accordance with a magnitude of the expected interlaminar stress.