Directionally Controllable CMC Insert for Crack Redirection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
CMC components in gas turbine engines are prone to cracks in high stress/strain regions, leading to premature failure and increased repair/replacement costs, as existing fabrication techniques do not effectively manage crack growth.
Innovation Solution
A directionally controllable CMC insert with optimized architecture is integrated into the CMC components to redirect cracks towards low crack growth regions, utilizing a shaped void and mechanical interlocking joints to minimize stress and prevent crack propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If CMC components are used in high-temperature gas turbine applications, then temperature resistance is improved, but crack susceptibility in high stress regions increases
Solution Approach 1:
The patent applies local quality by creating a transition zone with gradually changing fiber orientation angles (from 0° to 90° over a 5-10mm distance) rather than abrupt changes. This localized architectural modification at the insert-component interface redistributes stress and prevents crack initiation while preserving the overall high-temperature performance of the CMC component.
Solution Approach 2:
The patent segments the CMC component into distinct zones: the base component, the insert with optimized architecture, and a transition zone connecting them. This segmentation allows each zone to be optimized independently - the base for high-temperature performance, the insert for crack control, and the transition zone for stress distribution - thereby resolving the contradiction between temperature resistance and crack susceptibility.
2Power
If CMC components operate above proportional limit, then power output is improved, but crack formation in high stress regions increases
Solution Approach 1:
The patent implements preliminary action by pre-installing the insert with optimized fiber architecture into high stress regions before the component undergoes operational loading above the proportional limit. This pre-positioned structural reinforcement proactively manages stress distribution and crack propagation paths before cracks can form, enabling the component to safely operate at higher power levels.
Solution Approach 2:
The patent converts the harmful effect of high stress into a beneficial outcome by using the stress concentration zones (created by operating above proportional limit) to guide crack propagation along predetermined paths through the insert's optimized architecture. The insert transforms what would be random, damaging cracks into controlled, non-critical crack paths that do not compromise component integrity.
3Ease of manufacture
If conventional CMC fabrication techniques are used, then manufacturing simplicity is maintained, but crack growth control capability is insufficient
Solution Approach 1:
The patent applies the nested doll principle by placing the insert (a complete CMC structure with optimized architecture) inside the larger CMC component during fabrication. The insert is embedded within the base component's matrix, creating a nested structure where the inner insert provides crack growth control while the outer component provides structural integrity. This nesting approach integrates crack control functionality without requiring separate manufacturing processes.
4Strength
If CMC components are designed with high stress region reinforcement, then crack resistance is improved, but device complexity increases
Solution Approach 1:
The patent uses parameter changes by modifying only the fiber orientation angles within a limited region (the insert) while keeping the rest of the component's architecture standard. The fiber angles are varied systematically (0° to 90° gradients) only where needed for crack control, rather than changing the entire component's complex architecture. This localized parameter modification achieves enhanced crack resistance with minimal increase in overall device complexity.
Data Source
AI summary
A ceramic matrix composite (CMC) component including a plurality of layers of a CMC and a directionally controllable CMC insert. The directionally controllable CMC insert is disposed in the plurality of layers of a ceramic matrix composite. The directionally controllable CMC insert includes an optimized architecture to strengthen a high stress region of the CMC component. The directionally controllable CMC insert is geometrically configured and disposed within the plurality of layers of the CMC to redirect a crack in the CMC component toward a region of low crack growth driving force. A turbomachine and method of forming a turbomachine member including a plurality of layers of a CMC and having the directionally controllable CMC insert disposed in a shaped void are additionally disclosed.