Angled Resonance Probe Assembly for In-Situ Defect Inspection

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Solution Overview

Problem

Existing non-destructive testing methods for inspecting aircraft propulsion system components are inadequate for efficiently identifying internal defects with high accuracy and minimal downtime.

Innovation Solution

A resonance-based inspection system utilizing a probe assembly with a piezoelectric transducer and shape-memory alloy (SMA) rods, which includes a probe that can be translated and angled within a guide tube to facilitate precise ultrasonic testing of internal components, and a control assembly with galvanic isolation to prevent parasitic capacitance interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a probe assembly with SMA rods and piezoelectric transducers is used for resonance inspection, then measurement precision and detection accuracy are improved, but device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidprobe assembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The probe assembly employs a nested structure where the probe is disposed within the guide tube, and the SMA rods are positioned within the flexible cable assembly. This nesting allows multiple functional components to be integrated in a compact configuration, achieving high measurement precision without proportionally increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The probe assembly utilizes shape-memory alloy rods that change their physical state (angular bend) in response to temperature or electrical stimulus, enabling the probe to transition between retracted and deployed conditions. This parameter-based control mechanism allows precise positioning and angling of the piezoelectric transducer for accurate defect detection.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the probe is made axially translatable and angleable for precise positioning, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvepositioning precisionVSAvoidoperation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The probe assembly employs self-actuating mechanisms where the SMA rods automatically change configuration in response to environmental or electrical stimuli, enabling the probe to self-position and self-angle within the guide tube. This reduces the manual manipulation required by the operator while achieving precise positioning for resonance inspection.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If galvanic isolation is implemented to prevent parasitic capacitance interference, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvesignal accuracyVSAvoidcontrol assembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control assembly incorporates galvanic isolation mechanisms that act as intermediaries between the piezoelectric transducer and the measurement system. This isolation prevents parasitic capacitance interference from affecting the resonance inspection signals, thereby maintaining high measurement precision without requiring complex shielding or filtering circuits.

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

Enables accurate detection of internal defects in propulsion system components with reduced downtime and cost, allowing for efficient inspection of installed components without the need for removal from the aircraft.

Implementation Method 1

The probe includes a probe housing, at least one piezoelectric transducer... The at least one piezoelectric transducer is disposed within the probe housing at the distal end

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The at least one SMA rod is disposed at the proximate housing end and positioned within the probe housing and the flexible cable assembly. The at least one SMA rod is configured with a remembered angular bend disposed within the flexible cable assembly

Methodology Applied
Scientific EffectShape memory alloy effect: Shape Memory Alloy

Implementation Method 3

Resonance inspection system and method for using same... Various systems and methods are known in the art for inspecting a component for internal defects

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4647754A1Resonance inspection system and method for using same
Publication Date: 2025.11.12 RTX CORP
  • EP4647754A1 patent drawingFigure 1
  • EP4647754A1 patent drawingFigure 2
  • EP4647754A1 patent drawingFigure 3

AI summary

A probe assembly (70; 700) for a resonance inspection system includes an outer guide tube (704) and a probe (702). The outer guide tube (704) extends along a longitudinal axis (728) between and to a distal outer tube end and a proximate outer tube end. The probe (702) is axially translatable relative to the outer guide tube (704) along the longitudinal axis (728). The probe (702) includes a probe housing (712), at least one piezoelectric transducer (714), a flexible cable assembly, and at least one shape-memory alloy (SMA) rod (720). The probe (702) is selectively positionable in a retracted condition and a deployed condition. In the retracted condition, the probe (702) has a first axial probe position and the remembered angular bend is constrained within the outer guide tube (704). In the deployed condition, the probe (702) has a second axial probe position and the probe axis is oriented at a predetermined angle relative to the longitudinal axis (728) by the remembered angular bend.