Composite Fan Blade Airfoil Ply Segmentation
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Solution Overview
Problem
Existing composite fan blade designs face issues with delamination and crack propagation due to the segregation of plies, which limits the development of effective crack arresting mechanisms and damage tolerance, especially under impact loads like bird strikes.
Innovation Solution
The method involves dividing plies into smaller groups with varying orientations, thicknesses, and spacings, and bonding them under high pressure and temperature to create a laminated composite fan blade using Automated Fiber Placement (AFP), which disperses matrix concentrations and prevents crack propagation by creating a tortuous path for cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plies are arranged with uniform orientation and spacing, then manufacturing is simplified, but crack propagation resistance deteriorates
Solution Approach 1:
The patent divides the ply structure into multiple groups (first group with N1 plies at angle β1, second group with N2 plies at angle β2, third group with N3 plies at angle β3, etc.) where each group has different orientations and spacings. This segmentation creates a non-uniform interleaved pattern that disrupts crack propagation paths while maintaining manufacturing feasibility through systematic grouping.
Solution Approach 2:
The patent implements local variation in ply orientation and spacing by assigning different angles (β1, β2, β3, β4) and different numbers of plies (N1, N2, N3, N4) to different groups. This creates locally optimized regions with specific crack-arresting properties while maintaining overall structural integrity.
2Ease of manufacture
If plies are segregated into distinct orientation groups, then manufacturing process is simplified, but delamination resistance deteriorates
Solution Approach 1:
The patent segments plies into multiple groups with different orientations (N1 plies at β1, N2 plies at β2, etc.) but interleaves these groups in a specific sequence rather than placing all plies of one orientation together. This segmentation with interleaving prevents continuous delamination paths while keeping the manufacturing process systematic and manageable.
Solution Approach 2:
The patent adds the dimension of ply stacking sequence to the traditional two-dimensional ply orientation design. By controlling the number and arrangement of plies in each group (N1, N2, N3, N4) and their stacking order, the patent creates a three-dimensional interleaved structure that blocks delamination propagation in multiple directions.
3Manufacturing precision
If all tows have uniform thickness and spacing, then manufacturing precision is improved, but damage tolerance deteriorates
Solution Approach 1:
The patent maintains uniform tow properties within each individual ply to ensure manufacturing precision, but creates local variation between different plies by assigning different orientations (β1, β2, β3, β4) and different numbers of plies (N1, N2, N3, N4) to different groups. This local quality variation at the group level provides damage tolerance while preserving manufacturing precision at the tow level.
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 approach enhances the impact resistance and damage tolerance of fan blades by reducing delamination and crack propagation, improving the overall performance and life cycle of the turbine blades.
Implementation Method 1
bonding them under high pressure and temperature
Implementation Method 2
bonding them under high pressure and temperature
Data Source
AI summary
Disclosed herein is an article comprising a first group of plies having a number of plies N1 each having unidirectional tows oriented in a first direction β1 and a second group of plies having a number of plies N2 each having unidirectional tows oriented in a second direction β2; where β1 is not equal to β2; wherein N1 and N2 are both integer numbers. At least one of the first group of plies or the second group of plies has at least one tow of different thickness from another tow, has a different tow spacing from another tow spacing, or a combination thereof.