Removing Fiber-Reinforced Wrap from Fan Casing

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Solution Overview

Problem

The existing methods are inefficient and costly for removing fiber-reinforced wraps from metal portions of fan casings without damaging the underlying metal or the wrap, which is crucial for repairing corrosion or other damage in aerospace applications.

Innovation Solution

A method involving local heating of the fiber-reinforced wrap to soften the adhesive, followed by unwinding and rewinding onto a collection drum using a tensioning roller, allowing for the removal and reuse of the metal casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fiber-reinforced wrap is used on metal fan casing, then blade containment capability is improved, but removal and repair difficulty increases

Engineering Contradiction:
Improveblade containment capabilityVSAvoidremoval difficulty
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The fiber-reinforced wrap is divided into multiple circumferential layers that can be sequentially removed. The removal system processes one layer at a time by heating, peeling, and winding onto a collection drum, enabling systematic decomposition of the complex removal task into manageable segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Heat is applied to the fiber-reinforced wrap before removal to soften the adhesive bonding the wrap to the metal casing. This preliminary heating action reduces the bonding strength, making subsequent peeling and removal operations easier and less damaging to both the wrap and underlying metal structure.

Inventive Principle:
Principle #10Preliminary action

2Loss of substance

If conventional removal methods are used, then fiber-reinforced wrap can be removed, but damage to metal casing and wrap increases

Engineering Contradiction:
Improvematerial damageVSAvoidremoval process simplicity
Core Design Contradiction:
Loss of substanceVSEase of manufacture

Solution Approach 1:

A tensioning roller is introduced as an intermediary element between the fiber-reinforced wrap and the collection drum. This roller applies controlled tension to the wrap during removal, preventing excessive force that could damage the metal casing or the wrap itself, while still enabling effective separation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The removal process replaces purely mechanical force-based methods with a combined thermal-mechanical approach. Heating softens the adhesive to reduce bonding strength, allowing removal with significantly reduced mechanical force, thereby minimizing damage to both the wrap and metal casing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of repair

If fiber-reinforced wrap is removed for repair, then corrosion damage can be addressed, but removal cost and time increases

Engineering Contradiction:
Improvecorrosion repair accessibilityVSAvoidremoval time
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The removal system operates continuously by sequentially processing multiple circumferential layers of the fiber-reinforced wrap. As one layer is heated, peeled, and wound onto the collection drum, the system immediately transitions to the next layer without interruption, maximizing productivity and reducing total removal time.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The removal system is designed to recover intact fiber-reinforced wrap layers for potential reuse or proper disposal. By maintaining controlled tension and avoiding damage during removal, the system preserves the value of the expensive composite material, reducing waste and potential replacement costs.

Inventive Principle:
Principle #34Discarding and recovering

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

Enables efficient and cost-effective removal of the fiber-reinforced wrap without damaging the metal, facilitating repairs and reducing material waste by allowing for the reuse of the metal portion.

Implementation Method 1

The fiber-reinforced wrap may be heated to a temperature of about 120 °C to about 200 °C (e.g., about 125 °C to about 185 °C)

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3404217B1Method and system for removing a fiber-reinforced wrap from a fan casing
Publication Date: 2021.12.01 GENERAL ELECTRIC CO
  • EP3404217B1 patent drawingFigure 1
  • EP3404217B1 patent drawingFigure 2

AI summary

a method of removing a fiber-reinforced wrap (102) from a fan casing (18) compries heating the fiber-reinforced wrap (102) while on a metal support (104) of the fan casing (18), unwinding a layer (101) of the fiber-reinforced wrap (102) from the fan casing (18), and winding the layer (101) of the fiber-reinforced wrap (102) onto a collection drum (114). A system for removing a fiber-reinforced wrap (102) from a fan casing (18) comprises a mounting roll for a metal support (104) of the fan casing (18), a heat source (106) directed at the mount and configured to heat a surface of the fan casing (18) when loaded onto the mounting roll, and a collection drum (114).