Contrast Particle Bond Verification for Composite Joints

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Solution Overview

Problem

Existing methods for verifying the bond strength of composite joints in aircraft components, particularly those made from non-metallic composite materials, are inefficient and costly, often relying on destructive testing and indirect verification, which can miss disbonding issues during service life or impact events.

Innovation Solution

Incorporating contrast particles into the joint assembly that diffuse across the bond line when heat and pressure are applied, allowing for non-destructive inspection (NDI) techniques to verify successful bond formation by detecting their location within the components or adhesive layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If destructive testing is used to verify bond strength, then bond strength verification is achieved, but the components are damaged and additional testing on actual parts is impossible

Engineering Contradiction:
Improvebond strength verificationVSAvoidcomponent integrity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent uses contrast particles as tracers that copy the diffusion pathway of material across the bond line. By tracking these particles rather than destroying the component, we achieve bond strength verification while preserving component integrity. The particles serve as surrogates for the actual material flow during bonding.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces mechanical destructive testing with a non-destructive tracer-based inspection system. Instead of applying mechanical loads that destroy the component, we use contrast particles and non-destructive inspection methods (visual, optical, or other detection techniques) to verify bond quality.

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

2Measurement precision

If process verification coupons are used to verify bond strength, then bond strength can be assessed, but the process is time-consuming and laborious

Engineering Contradiction:
Improvebond strength assessmentVSAvoidverification process efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts the verification function from separate coupon testing and integrates it directly into the actual component during manufacturing. By incorporating contrast particles into the components themselves rather than using separate test coupons, we eliminate the time-consuming process of forming, testing, and correlating coupon results with actual component performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary action by incorporating contrast particles into the components during the manufacturing process itself, before bonding occurs. This eliminates the need for subsequent separate verification steps, as the tracers are already in place to indicate bond quality once the bonding is complete.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If visual inspection is used to detect disbonding, then inspection is simple, but disbonding is difficult to detect

Engineering Contradiction:
Improveinspection simplicityVSAvoiddisbonding detection capability
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses contrast particles that create visible color or optical changes at the bond line. When disbonding occurs, the contrast particles remain on one side of the gap, creating a visible indicator that can be easily detected through simple visual or optical inspection, thereby maintaining inspection simplicity while dramatically improving disbonding detection capability.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent introduces contrast particles as an intermediary substance that makes the invisible bond interface visible. These particles act as mediators between the bond line and the inspection system, translating the subtle condition of bonding into easily observable contrast patterns that maintain inspection simplicity while enhancing detection precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If indirect verification methods are used, then bond strength can be inferred, but direct verification of bond formation is not achieved

Engineering Contradiction:
Improvebond strength inferenceVSAvoiddirect bond verification
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent uses contrast particles that directly copy and trace the material diffusion pathway across the bond line. This provides direct verification of bond formation by showing exactly where material has flowed, eliminating the need for indirect inference methods. The particles serve as direct tracers of the bonding process itself.

Inventive Principle:
Principle #26Copying

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 direct and efficient verification of bond strength without destructive testing, reducing costs and time, and providing a reliable method to detect potential disbonding issues before they become critical.

Implementation Method 1

the contrast particles diffuse across a bond line defined between the components

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

When a predetermined amount of heat and pressure are applied to the components, the contrast particles diffuse across a bond line

Methodology Applied
Scientific EffectThermal energy input: Heating

Implementation Method 3

When a predetermined amount of heat and pressure are applied to the components, the contrast particles diffuse across a bond line

Methodology Applied
Scientific EffectMechanical pressure: Compression

Data Source

PatentEP3002106B1Method of inspecting joint assemblies
Publication Date: 2020.03.25 THE BOEING CO
  • EP3002106B1 patent drawingFigure 1~2
  • EP3002106B1 patent drawingFigure 3~4
  • EP3002106B1 patent drawingFigure 5

AI summary

A joint assembly (218) is provided. The joint assembly (218) includes a first component (202) including a first bond surface (206) and a second component (204) including a second bond surface (208) coupled to the first bond surface (206) such that a bond line is defined therebetween. At least one of the first and second components (202, 204) includes a plurality of contrast particles (222, 224) that diffuse across the bond line when a predetermined amount of heat and pressure are applied to the first and second components (202, 204).