Gas Turbine Blade Composite Ply Segmentation for Dovetail Strength
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Solution Overview
Problem
Existing rotor blades in gas turbine engines face mechanical and thermal stresses, leading to cracking and failure due to zones of weakness created by supplemental composite plies in the dovetail area, which increases the likelihood of failure under operational stresses.
Innovation Solution
A method and system for manufacturing blades by layering first plies that extend the length of the blade with second plies that only partially extend the length, interspersed throughout the first plies to increase the cross-sectional area and form a structural core, using a mold and bonding process to spread apart the plies and reduce resin pockets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If supplemental composite plies are inserted near the root of the blade to increase cross-sectional area, then the cross-sectional area is increased, but zones of weakness are created throughout the dovetail
Solution Approach 1:
The blade structure is segmented into two types of plies: first plies that extend substantially the full length of the blade span, and second plies that are supplemental plies inserted near the root. This segmentation allows the first plies to provide continuous structural support while the second plies locally increase the cross-sectional area in the dovetail region without creating zones of weakness throughout the entire blade length.
Solution Approach 2:
The invention applies local quality by having different plies serve different functions at different locations. The first plies provide continuous span-wise support, while the second plies are strategically placed only where additional cross-sectional area is needed near the root to form the dovetail coupling, thereby avoiding unnecessary material in other regions and preventing zones of weakness.
2Area of moving object
If supplemental composite plies are inserted near the root of the blade, then the cross-sectional area is increased, but the likelihood of blade failure increases under thermal and mechanical stresses
Solution Approach 1:
By segmenting the ply structure into first plies extending the full span and second plies localized near the root, the invention ensures that the supplemental material is only placed where structurally necessary. This prevents the creation of weak zones in other critical regions of the blade while still achieving the required cross-sectional area for strength in the dovetail region.
Solution Approach 2:
The invention implements local quality by varying the ply configuration based on local structural requirements. The first plies provide uniform support throughout the blade span, while the second plies are locally inserted only where additional strength and cross-sectional area are needed near the root, maintaining optimal strength-to-weight ratio and avoiding unnecessary material that could create weakness zones.
3Area of moving object
If second plies are interspersed throughout the first plies to spread them apart, then the cross-sectional area is increased, but the manufacturing complexity increases
Solution Approach 1:
The manufacturing process is segmented into providing first plies that extend the full span and second plies that are supplemental and shorter. This segmentation simplifies the layering process compared to attempting to create the same geometry with uniformly long plies, as the shorter second plies can be more easily positioned and bonded only where needed to achieve the desired cross-sectional area increase.
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 load-carrying capacity, reduces the likelihood of cracking, and increases the reliability and longevity of the blades while maintaining a uniform core structure, thereby extending the blade's useful life and reducing manufacturing costs.
Implementation Method 1
bonding the plurality of first plies to the plurality of second plies to facilitate forming a structural core of the blade
Data Source
AI summary
A method of manufacturing a blade is provided. The method includes providing a plurality of first plies, each of the first plies sized to extend substantially the length of a span of the blade and providing a plurality of second plies, each of the second plies sized to extend only partially the length of the span of the blade. The method also includes layering the plurality of first plies and the plurality of second plies in a mold such that the plurality of second plies is interspersed throughout the plurality of first plies to spread apart the plurality of first plies to facilitate increasing a cross-sectional area of the blade and bonding the plurality of first plies to the plurality of second plies to facilitate forming a structural core of the blade.