Magnetostrictive Adhesive Bond Integrity Monitoring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current adhesive bonding techniques in aircraft composite structures lack sufficient confidence and reliability, leading to the use of metal fasteners which increase weight, complexity, and cost, while existing inspection methods are inadequate for establishing bond integrity.

Innovation Solution

Incorporating strain-sensitive magnetostrictive material into adhesives, which changes magnetization in response to physical strain, allowing for non-destructive detection of bond strength and irregularities through magnetic property measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal fasteners are added to bonded joints to ensure structural reliability, then the reliability of the joint is improved, but the weight of the aircraft structure increases

Engineering Contradiction:

Improvejoint reliabilityVSAvoidaircraft weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces the mechanical fastening system with a magnetic sensing system. Magnetostrictive material embedded in the adhesive layer detects bond integrity through magnetic property changes, eliminating the need for metal fasteners while maintaining joint reliability through non-destructive monitoring.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from mechanical (fastener presence) to magnetic (magnetization properties). By monitoring magnetic property changes in the magnetostrictive material under stress, the system detects bond failures without adding mechanical fasteners, thus maintaining reliability while reducing weight.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If metal fasteners are used to reinforce bonded joints, then the structural integrity is improved, but the device complexity increases

Engineering Contradiction:

Improvestructural integrityVSAvoidfabrication complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the adhesive bonding function with the sensing function by embedding magnetostrictive material directly into the adhesive layer. This integration eliminates separate fastener components and simplifies the fabrication process while maintaining structural integrity through combined bonding and monitoring.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the complex mechanical fastening system with a simplified magnetic sensing approach. The magnetostrictive material provides both structural bonding and integrity monitoring functions, reducing device complexity while maintaining reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If metal fasteners are installed in composite structures, then the load-bearing capacity is improved, but the manufacturing time and cost increase

Engineering Contradiction:

Improveload-bearing capacityVSAvoidfabrication time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The patent incorporates magnetostrictive material into the adhesive before the bonding process. This preliminary integration eliminates the need for separate fastener installation steps, reducing manufacturing time and cost while maintaining load-bearing capacity through the combined adhesive-magnetic material system.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces time-consuming mechanical fastener installation with a simplified process of embedding magnetostrictive material in the adhesive during normal bonding operations. This substitution maintains strength while significantly reducing fabrication time and complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If fastener holes are created in composite structures, then the joint reliability is improved, but the susceptibility to corrosion and lightning strike increases

Engineering Contradiction:

Improvejoint reliabilityVSAvoidcorrosion and lightning strike susceptibility

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical fasteners that require holes with a magnetic sensing system embedded in the adhesive. This substitution eliminates penetration holes, thereby eliminating pathways for corrosion and lightning strike while maintaining joint reliability through magnetic monitoring of bond integrity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 non-destructive assessment of adhesive bond strength and detection of weak points, reducing the need for metal fasteners and improving the reliability of adhesive bonds, thereby enhancing the structural integrity and reducing fabrication complexities.

Implementation Method 1

Incorporating strain-sensitive magnetostrictive material into adhesives, which changes magnetization in response to physical strain

Methodology Applied

Scientific EffectMagnetostriction: Magnetostriction

Data Source

PatentEP2070688B1Aircraft structures bonded with adhesive including magnetostrictive material

Publication Date: 2018.08.29 THE BOEING CO

Figure 1~2
Figure 3~7
Figure 5~6

AI summary

First and second aircraft structures (110,120) are bonded together with an adhesive (130) including strain-sensitive magnetostrictive material.