Powerplant Defect Inspection with Detrended Vibration Signals

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Solution Overview

Problem

Existing non-destructive inspection methods for internal defects in powerplant components are inadequate, particularly in detecting small defects with minimal downtime and cost.

Innovation Solution

An inspection method using a piezoelectric actuator and sensor to induce vibrations in powerplant components, measure vibratory responses, and filter the data to detect defects, including techniques like detrending and liftering to remove noise from the measurement data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing non-destructive inspection methods are used, then internal defects can be detected, but small defects cannot be detected with sufficient accuracy and the process requires significant downtime

Engineering Contradiction:

Improvedefect detection accuracyVSAvoidaircraft downtime

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies mechanical vibration by inducing vibrations in the powerplant component across a frequency range and measuring the vibratory response. The piezoelectric transducer generates mechanical vibrations that propagate through the component, and defects are detected by analyzing changes in the vibratory response. This approach enables rapid inspection without requiring aircraft shutdown or disassembly, thus reducing downtime while maintaining high detection accuracy for small defects.

Inventive Principle:

Principle #18Mechanical vibration

2Productivity

If vibration-based inspection is used, then inspection speed is improved, but background noise from the inspection scope head interferes with defect detection

Engineering Contradiction:

Improveinspection speedVSAvoidsignal quality

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent extracts and removes the trend component from the measured vibratory response data through detrending operations. By separating the trend data (which contains background noise from the inspection scope head) from the actual defect-related signal, the method isolates the useful information. This extraction process eliminates interference from the inspection scope head while preserving the defect detection capability, maintaining high signal quality during rapid inspection.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter representation of the measurement data by transforming the vibratory response into a detrended form. By applying mathematical transformations (detrending and liftering) to the raw data, the method alters the parameter space to separate signal from noise. This parameter change enables the system to maintain high inspection speed while improving signal quality by removing background interference.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the inspection device is preloaded against the component surface, then measurement contact is improved, but the inspection device complexity increases

Engineering Contradiction:

Improvemeasurement contactVSAvoidinspection device structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a piezoelectric transducer that serves multiple functions: it acts as both the actuator to induce vibrations and the sensor to measure the vibratory response. This multi-functional device eliminates the need for separate actuators and sensors, reducing overall device complexity. The single transducer can be preloaded against the component surface to ensure reliable measurement contact while maintaining a simple, compact inspection device structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 detection of internal defects in powerplant components with minimal aircraft downtime and cost, identifying defects as small as 50 mils (0.05 inches) with high accuracy.

Implementation Method 1

Vibrations are induced in the powerplant component across a frequency range using a piezoelectric actuator

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

A vibratory response excited by the vibrations is measured using a piezoelectric sensor

Methodology Applied

Scientific EffectPiezoelectric effect: Converse Piezoelectric Effect

Data Source

PatentEP4657059A1Filtering out background noise from measurement data during defect inspection

Publication Date: 2025.12.03 RTX CORP

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AI summary

An inspection method is provided during which a head of an inspection scope is inserted into an interior of a powerplant. The head of the inspection scope includes an actuator and a sensor. The powerplant includes a component within the interior of the powerplant. The head of the inspection scope is abutted against a surface of the component. Vibrations in the component are induced using the actuator. A vibratory response excited by the vibrations is measured using the sensor to provide measurement data. The measurement data is filtered to provide filtered data, and the filtering includes detrending the measurement data.