Flexible Inspection Device for Composite Structures

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current non-destructive inspection methods, particularly for composite structures, face challenges such as acoustic impedance mismatch between air and solids, leading to reflection and loss of ultrasonic scan quality, and are limited by slow inspection speeds due to the need for manual scanning of small areas.

Innovation Solution

The inspection device features a housing with a chamber for a transducer and a fluid passage that maintains a laminar flow of coupling material, using a phased array transducer and a nozzle with a flexible material to ensure efficient signal transmission and minimize damage during contact, allowing for faster and more robust inspection of composite structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a coupling material is used to transmit ultrasonic signals, then signal transmission quality is improved, but inspection speed decreases due to the need for slow, laminar flow

Engineering Contradiction:
Improveultrasonic scan qualityVSAvoidinspection speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies dynamics by making the housing flexible rather than rigid, allowing it to adapt to surface contours while maintaining contact. This flexibility enables faster inspection speeds while preserving the necessary coupling material flow for quality ultrasonic transmission, resolving the contradiction between measurement precision and productivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state and flow characteristics of the coupling material by controlling its delivery through the flexible housing. By optimizing the flow parameters (laminar flow maintenance) while allowing housing deformation, the system achieves both high scan quality and improved inspection speed, addressing the trade-off between these two parameters.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If manual scanning of small areas is performed, then ultrasonic signal transmission is maintained, but inspection time increases significantly

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidinspection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the inspection process by using multiple piezoelectric elements arranged in an array within the housing. This segmentation allows parallel scanning of multiple areas simultaneously, reducing total inspection time while maintaining reliable signal transmission through each element, thus resolving the contradiction between reliability and time loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables continuous useful action by allowing the flexible housing to maintain constant contact with the surface during movement, ensuring uninterrupted ultrasonic signal transmission. This continuity eliminates the need for repeated positioning and setup, significantly reducing inspection time while preserving signal reliability.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of operation

If air is used as the medium between transducer and structure, then inspection setup is simplified, but acoustic impedance mismatch causes signal reflection and quality loss

Engineering Contradiction:
Improveinspection setup simplicityVSAvoidultrasonic signal quality
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces a coupling material as an intermediary substance delivered through the flexible housing between the transducer and the structure. This intermediary resolves the acoustic impedance mismatch problem by providing a transitional medium that enables effective signal transmission, while the simplified housing design maintains ease of operation, thus resolving the contradiction between operational simplicity and measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration ensures effective ultrasonic signal transmission with reduced turbulence, enabling faster and more accurate inspection of composite structures by maintaining laminar flow and minimizing damage during contact.

Implementation Method 1

An ultrasonic signal is transmitted by at least one of the transducers, propagated through the structure, and received by the other transducer or receiver sensor

Methodology Applied
Scientific EffectUltrasonic transmission: Ultrasound

Implementation Method 2

Ultrasonic testing generally requires a coupling material (e.g., a fluid, such as water) to aid transmission of the ultrasonic energy to the test specimen because the acoustic impedance mismatch between air and solids (i.e., the test specimen) is unacceptably large

Methodology Applied
Scientific EffectAcoustic impedance matching: Acoustic Lubrication

Implementation Method 3

when a flowing fluid, such as water, is utilized as a coupling material, flow of the fluid should be in a substantially laminar regime in order to effectively pass the ultrasonic signal to the structure to be inspected without substantially altering the ultrasonic signal

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Data Source

PatentEP3405782B1Inspection devices and related systems and methods
Publication Date: 2022.11.16 NORTHROP GRUMMAN SYSTEMS CORP
  • EP3405782B1 patent drawingFigure 1
  • EP3405782B1 patent drawingFigure 2
  • EP3405782B1 patent drawingFigure 3~4

AI summary

Inspection devices include a nozzle portion having at least one opening and a transducer disposed in a rear chamber of a housing. The housing has at least one fluid channel defined in the housing and extending along at least a portion of the rear chamber. The at least one fluid channel is configured to supply a fluid into a forward chamber of the housing proximate the transducer. Related methods include operating an inspection device.