Composite Laminate Compliant Layers for Delamination Resistance
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Solution Overview
Problem
Composite laminates manufactured from the same fibrous material and polymeric-matrix material are prone to delamination and matrix cracks, especially under high cycle dynamic loading, necessitating an improved manufacturing method to enhance their structural integrity.
Innovation Solution
Incorporating 'compliant' layers with different polymeric-matrix materials or fibrous materials between 'baseline' layers, where the compliant layers are stronger than the baseline layers, to impede delamination initiation and propagation by redistributing stresses and increasing tensile strength, particularly at locations of peak interlaminar stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If composite laminate is manufactured from the same fibrous material and polymeric-matrix material throughout, then manufacturing simplicity is maintained, but the laminate becomes prone to delamination and matrix cracks under high cycle dynamic loading
Solution Approach 1:
The patent applies local quality by introducing compliant layers at specific locations within the composite laminate where peak interlaminar stresses occur. These compliant layers have different material properties (higher compliance) compared to the baseline layers, creating local variations in quality that specifically address stress concentration areas without changing the entire laminate structure. This selective placement resolves the contradiction by maintaining manufacturing simplicity while improving reliability at critical locations.
Solution Approach 2:
The patent employs composite materials by combining baseline layers (made from standard fibrous material and polymeric-matrix material) with compliant layers (made from different polymeric-matrix materials or fibrous materials) to create a multi-layered composite structure. This composite approach allows the laminate to leverage the strengths of different materials: the baseline layers provide overall structural integrity while the compliant layers provide enhanced resistance to delamination and matrix cracks through their superior compliance characteristics.
2Strength
If compliant layers are added to impede delamination and increase tensile strength, then structural integrity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the composite laminate into distinct baseline layers and compliant layers. This segmentation allows each layer type to be optimized for its specific function: baseline layers for overall structural support and compliant layers for stress management and delamination resistance. The segmented structure improves strength and integrity while managing manufacturing complexity through modular layer design that can be implemented systematically.
Solution Approach 2:
The compliant layers are selectively placed only at locations where peak interlaminar stresses occur, rather than throughout the entire laminate. This local application approach improves structural integrity at critical stress points while minimizing the overall addition of complexity to the manufacturing process. The localized strategy ensures that the benefits of compliant layers are concentrated where most needed without unnecessarily complicating the entire manufacturing system.
3Reliability
If compliant layers are placed at locations of peak interlaminar stresses, then delamination propagation is impeded, but the number of layers and structural complexity increases
Solution Approach 1:
The patent implements local quality by placing compliant layers specifically at locations where peak interlaminar stresses occur and where delamination is most likely to initiate or propagate. This targeted approach ensures that the additional layers are concentrated in regions that benefit most from their presence, thereby impeding delamination propagation effectively while minimizing the overall increase in the number of layers compared to a uniform multi-layer design.
Solution Approach 2:
By segmenting the laminate structure into baseline layers and strategically positioned compliant layers, the patent creates a differentiated architecture that addresses delamination risks at specific critical locations. This segmentation allows the structure to maintain fewer total layers compared to a uniformly thick multi-layer design, as compliant layers are added only where necessary rather than throughout the entire laminate stack.
Data Source
AI summary
In some embodiments, a method of manufacturing composite laminate, including providing a first fibrous material having a plurality of fibers, providing a second fibrous material having a plurality of fibers, disposing the fibers of the first fibrous material in a first polymeric matrix, disposing the fibers of the second fibrous material in a second polymeric matrix, laying up a plurality of the first fibrous material on a rigid structure, laying up the second fibrous material on the rigid structure, wherein the first fibrous material is in contact with the second fibrous material, curing the first polymeric matrix, creating a plurality of baseline layers from the plurality of first fibrous material and the first polymeric matrix, and curing the second polymeric matrix, creating a compliant layer from the second fibrous material and the second polymeric matrix. The compliant layer is stronger than each individual baseline layers.