Woven-Fiber Airfoil Support Rib for Hoop Stress Relief

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing support ribs in airfoils, formed with unidirectional fibers, have limited stiffness and thermal conductivity in the hoop direction, failing to effectively alleviate hoop stresses and thermal gradients caused by pressure differentials.

Innovation Solution

A support rib design incorporating a central joined section and end sections with woven fibers in a ceramic matrix, oriented at perpendicular angles to enhance load carrying and thermal conductivity, particularly in the hoop direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If unidirectional fibers are used in support ribs, then manufacturing is simplified, but stiffness and thermal conductivity in the hoop direction are limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidstiffness in hoop direction
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies composite materials by combining unidirectional fibers with woven fibers in the support rib structure. The unidirectional fibers provide manufacturing simplicity and strength in the thickness direction, while the woven fibers (arranged in hoop and axial directions) enhance stiffness and thermal conductivity in the hoop direction. This composite approach allows the support rib to simultaneously achieve ease of manufacture and improved mechanical properties in multiple directions.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If unidirectional fibers are used in support ribs, then manufacturing is simplified, but thermal conductivity in the hoop direction is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidthermal conductivity in hoop direction
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent uses composite materials combining unidirectional and woven fiber structures to address thermal conductivity limitations. The woven fibers arranged in the hoop direction create thermal conduction pathways that efficiently transfer heat across the support rib, while the unidirectional fibers maintain manufacturing simplicity. This composite structure enables the support rib to conduct heat effectively in the hoop direction without complicating the manufacturing process.

Inventive Principle:
Principle #40Composite materials

3Strength

If support ribs are added to reduce bulging, then structural integrity is improved, but device complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidairfoil structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies local quality by varying the fiber orientation and composition in different regions of the support rib. The woven fibers are concentrated in the hoop and axial directions where they are most effective at reducing bulging and enhancing stiffness, while unidirectional fibers are used in the thickness direction for manufacturing simplicity. This localized optimization allows the support rib to provide maximum structural integrity with minimal added complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4640992A1Support rib for airfoil
Publication Date: 2025.10.29 RTX CORP
  • EP4640992A1 patent drawingFigure 1~2
  • EP4640992A1 patent drawingFigure 3
  • EP4640992A1 patent drawingFigure 4~5

AI summary

A support rib (40) and an airfoil (10) having a support rib (40) where the support rib (40) is formed from a central joined section(80) which includes at least one ply of woven bidirectional fibers (230, 240, 250), a first end section (90), and a second end section (100) where the first and second end sections (90, 100) are positioned on opposing ends of the central joined section (80). The first end section (90) and the second end section (100) each have at least two plies (170, 180, 190, 200) of woven bidirectional fibers (230, 240, 250). The support rib (40) joins two radial tubes (50, 60) to form an airfoil (10) where the central joined section (80) of the support rib (40) joins the adjacent circumferential surfaces (300, 310) of the radial tubes (50, 60) and the first and second end sections (90, 100) join to the curved surfaces of the outer circumferential surfaces (300, 310) of the radial tubes (50, 60), respectively.