Wrinkle Detection in Fiber Reinforced Laminates

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Solution Overview

Problem

Current methods for detecting wrinkles in fibre reinforced laminated structures are inadequate, as they often require destructive testing or rely on assumptions about fibre orientation, and existing non-destructive methods lack precision in identifying thermal anomalies.

Innovation Solution

A method involving local heating or cooling of the structure with controlled movement of a heat source and temperature measurement along defined paths, allowing for accurate detection of temperature anomalies indicative of wrinkles without requiring knowledge of material thermal properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thermal testing methods are used to detect wrinkles, then non-destructive detection is achieved, but measurement precision is insufficient due to artifacts and lack of knowledge about material thermal properties

Engineering Contradiction:
Improvenon-destructive detection capabilityVSAvoidwrinkle detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by systematically varying heating parameters (temperature, duration, spatial distribution) and measuring the resulting temperature changes over time. By changing multiple parameters simultaneously and analyzing their combined effect on temperature evolution, the method achieves precise wrinkle detection without requiring prior knowledge of material thermal properties. The key is to monitor how temperature changes propagate through the laminate and how wrinkles alter this propagation pattern.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If conventional inspection methods are used, then simplicity is maintained, but detection precision of temperature anomalies is insufficient

Engineering Contradiction:
Improveinspection simplicityVSAvoidtemperature anomaly detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements continuity of useful action by performing continuous or sequential temperature measurements at multiple locations and time points during the heating process. Rather than taking single snapshots, the method continuously monitors temperature evolution, allowing precise detection of anomalies that manifest as deviations from expected temperature patterns. This continuous measurement approach maintains operational simplicity while dramatically improving detection precision.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If material thermal property knowledge is required for detection, then measurement precision improves, but device complexity and preparation time increase

Engineering Contradiction:
Improvewrinkle detection accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by designing a measurement system that automatically determines material thermal properties during the inspection process itself. The system performs heating, measures temperature responses, and uses this data to characterize the specific laminate being inspected without requiring pre-characterization or external reference data. This self-calibrating approach eliminates the need for complex pre-processing while maintaining high measurement precision.

Inventive Principle:
Principle #25Self-service

4Device complexity

If single-point temperature measurement is used, then device complexity is reduced, but measurement precision and wrinkle localization accuracy deteriorate

Engineering Contradiction:
Improvemeasurement system simplicityVSAvoidwrinkle localization accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the measurement task into multiple spatial segments (multiple measurement locations across the laminate surface) and temporal segments (multiple measurement time points during heating). This segmented approach allows precise localization of wrinkles by comparing temperature anomalies across different spatial segments while maintaining relatively simple measurement devices at each location. The segmentation strategy transforms a single complex measurement into multiple simpler measurements that collectively provide high precision.

Inventive Principle:
Principle #1Segmentation

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 method enables precise, non-destructive detection and measurement of wrinkle length with high reproducibility, minimizing artifacts and allowing for determination of wrinkle extent and length without needing specific thermal property knowledge.

Implementation Method 1

the structure is locally heated or cooled with the location of the heating or cooling being moved along a defined path

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The temperature of the structure is measured at a measuring location being different from the location of the heating or cooling

Methodology Applied
Scientific EffectThermal radiation detection: Thermal Radiation

Data Source

PatentEP2492671B1Method of detecting wrinkles in a fiber reinforced laminated structure
Publication Date: 2015.05.06 SIEMENS AG
  • EP2492671B1 patent drawingFigure 1
  • EP2492671B1 patent drawingFigure 2~3
  • EP2492671B1 patent drawingFigure 4

AI summary

A method of detecting wrinkles (3) in a fiber reinforced laminated structure (1) is provided. In this method, - the structure (1) is locally heated or cooled, the location of the heating or cooling being moved along a defined path (7), - the temperature of the structure (1) is measured at a measuring location being different from the location of the heating or cooling, the measuring location being moved along the same path (7) as the location of the heating or cooling, and - wrinkles (3) are detected from temperature anomalies found along the defined path (7).