Propeller Blade Foam Core Crack Prevention with Composite Insert

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Modern propeller blades face issues with foam core cracking under shear forces and stress, which can lead to structural instability and potential failure during flight.

Innovation Solution

Incorporating a lightweight insert made of carbon, fiberglass, or composite materials within the propeller blade to maintain the fixed relation between the face and camber sides, reducing the likelihood of foam core cracking and stabilizing the blade under load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a foam core is used in the propeller blade to reduce weight, then the blade becomes lighter and more efficient, but the foam core is prone to cracking under shear forces and stress

Engineering Contradiction:
Improveblade weightVSAvoidfoam core stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by combining foam core with a lightweight insert made of carbon, fiberglass, or composite materials. This composite structure maintains the weight advantages of foam while adding the structural strength and crack resistance of the insert material, directly resolving the contradiction between lightweight design and structural reliability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The lightweight insert is disposed within the foam core in a nested configuration, where the insert is positioned inside the larger foam structure. This nesting approach allows the foam to provide overall shape and weight reduction while the inner insert reinforces critical areas against shear forces and prevents cracking

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If the blade structure is simplified to reduce manufacturing complexity, then production becomes easier, but the blade may lack sufficient structural support to prevent foam core cracking

Engineering Contradiction:
Improveblade manufacturingVSAvoidblade structural strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The blade structure is segmented into distinct functional components: the foam core for weight reduction and shape, the lightweight insert for structural reinforcement, and the resin impregnated fabric for surface protection and additional strength. This segmentation allows each component to be optimized independently while maintaining overall manufacturing efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lightweight insert is strategically positioned at specific locations within the foam core where shear forces and stress are most likely to cause cracking. This local reinforcement approach provides targeted structural support exactly where needed, rather than uniformly strengthening the entire blade, thus maintaining ease of manufacture while enhancing local strength

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2660143B1Propeller blade with lightweight insert and bulkheads
Publication Date: 2021.07.07 RATIER FIGEAC SAS
  • EP2660143B1 patent drawingFigure 1
  • EP2660143B1 patent drawingFigure 2
  • EP2660143B1 patent drawingFigure 3A~3B

AI summary

A propeller blade (100) includes a foam core (104) and a structural layer (106) that surrounds at least a portion of the foam core (104) and includes a face side (107) and a camber side (109). The propeller blade (100) also includes an insert (105) disposed in the foam core (104) in operable contact with the face side (107) and the camber side (109) of the structural layer (106) and one or more bulkheads (602) disposed in the form core (104) and oriented normal to the insert (105).