Composite Casing Omega Stiffener Winding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aeronautical gas turbine fan casings made of composite materials face challenges in achieving sufficient stiffness while minimizing weight, as thinning certain areas for weight reduction compromises mechanical resistance and dynamic behavior, particularly under dynamic stress from rotating fan blades.
Innovation Solution
Incorporating an omega-type stiffening element between the before-last and last turns of the fiber texture during the manufacturing process, with reduced warp thread size in the last turn covering the stiffening element, enhances stiffness and reliability while reducing overall weight by allowing thinner sections without compromising rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the casing thickness is reduced to decrease weight, then the weight of the casing is reduced, but the mechanical resistance and stiffness of the casing deteriorate
Solution Approach 1:
The patent employs composite materials with fiber reinforcement (carbon, glass, aramid, or ceramic fibers) combined with organic matrix (epoxy, bismaleimide, or polyimide resin) to create a casing that achieves high strength-to-weight ratio. The fiber reinforcement provides mechanical resistance while the organic matrix binds the fibers, enabling weight reduction without compromising strength.
Solution Approach 2:
The patent implements local thickening at specific areas of the casing where mechanical resistance is critical, while maintaining thinner sections in areas where weight reduction is prioritized. This is achieved by adjusting the number of fiber texture layers and their orientation in different regions of the casing during the winding process.
2Weight of moving object
If the casing thickness is reduced to decrease weight, then the weight of the casing is reduced, but the stiffness of the casing deteriorates
Solution Approach 1:
The composite material structure with fiber reinforcement provides high stiffness-to-weight ratio. The directional arrangement of fibers in the fiber texture layers allows optimization of stiffness in specific directions while minimizing weight, addressing the contradiction between weight reduction and stiffness maintenance.
Solution Approach 2:
The patent applies varying fiber layer configurations and orientations in different regions of the casing to locally enhance stiffness where required while maintaining overall weight reduction. The fiber texture winding process allows precise control of material distribution to achieve optimal stiffness-weight balance.
3Stability of the object's composition
If add-on stiffeners are attached to the casing to increase stiffness, then the stiffness of the casing is increased, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the stiffening function directly into the casing structure by incorporating fiber reinforcement layers and strategic thickening zones during the primary manufacturing process. This integration eliminates the need for separate add-on stiffeners and their associated attachment processes, reducing device complexity while maintaining stiffness.
Solution Approach 2:
The stiffness-enhancing features are built into the casing structure during the initial fiber preform creation and winding processes, before final assembly. The fiber texture layers are arranged in advance to provide structural rigidity, eliminating the need for subsequent stiffening operations.
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
The method increases the stiffness of the composite-material casing, simplifies manufacturing, and ensures reliable attachment of stiffening elements, reducing the casing's weight while maintaining or improving its natural frequency response to dynamic stress.
Implementation Method 1
the winding of the fiber texture around several superimposed turns on a mandrel with a profile corresponding to that of the casing to be manufactured in order to obtain a fiber preform
Implementation Method 2
the densification of the preform by a matrix is carried out, the matrix being notably obtainable by injection and curing of a resin in the fiber preform
Implementation Method 3
injection and curing of a resin in the fiber preform
Implementation Method 4
at least one stiffening element being interposed between the before-last turn and the last turn of the fiber texture, the stiffening element projecting over the outer surface of the before-last turn
Data Source
AI summary
A method for manufacturing a composite-material casing for a gas turbine, includes producing by three-dimensional weaving a fiber texture in the form of a strip, winding of the fiber texture around several superimposed turns on a mandrel with a profile corresponding to that of the casing to be manufactured in order to obtain a fiber preform of a shape corresponding to that of the casing to be manufactured, and densifying the fiber preform by a matrix. During the winding of the last turn of the fiber texture on the mandrel, at least one stiffening element is interposed between the before-last turn and the last turn of the fiber texture. The stiffening element projects over the outer surface of the before-last turn of the fiber texture. The stiffening element has an axial section of omega-type shape.