Complimentary Golay Coded Thermal Wave Imaging for CFRP Defect Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermal imaging techniques for identifying defects in Carbon Fibre Reinforced Plastic (CFRP) materials, such as pulse compression based aperiodic thermal wave imaging, have limited sensitivity due to energy redistribution into side lobes, making it difficult to detect defects effectively.
Innovation Solution
The method involves generating a reconstructed zero mean temperature from the thermal response, creating first and second pulse compressed thermographic single pixel profiles, and calculating a third pulse compressed thermographic value based on the auto-correlation function of these profiles, which concentrates energy into the main lobe and reduces side lobe leakage, thereby improving defect identification sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional pulse compression based aperiodic thermal wave imaging is used, then defect identification can be performed, but sensitivity is limited due to energy redistribution into side lobes
Solution Approach 1:
The patent segments the thermal wave signal into multiple frequency components and processes them separately through frequency-domain filtering. By dividing the broadband thermal wave into discrete frequency bands and applying individual filtering operations, the method achieves better energy concentration and reduced side lobe effects compared to conventional single-stage pulse compression.
Solution Approach 2:
The patent changes the frequency domain parameters of the thermal wave signal by applying frequency-domain filtering and phase manipulation. By modifying the spectral characteristics and phase relationships of different frequency components, the method optimizes energy distribution in the compressed output, reducing side lobe leakage while maintaining main lobe intensity for improved defect detection sensitivity.
2Manufacturing precision
If frequency modulated thermal wave imaging is used, then test resolution can be improved, but side lobe leakage increases reducing overall sensitivity
Solution Approach 1:
The patent extracts and removes the harmful side lobe components through frequency-domain filtering. By identifying and isolating the side lobe energy in the frequency domain and applying selective filtering, the method separates the useful main lobe signal from the harmful side lobe leakage, thereby improving overall detection sensitivity while maintaining test resolution.
Solution Approach 2:
The patent converts the side lobe energy, which is normally harmful, into beneficial information by analyzing its spectral characteristics. The frequency-domain processing methodology transforms side lobe leakage into structured frequency components that can be filtered or weighted to enhance defect contrast, turning what was previously a disadvantage into an advantage for sensitivity improvement.
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 approach enhances the sensitivity of defect detection in CFRP materials by focusing most of the supplied energy into the main lobe, resulting in improved test sensitivity and resolution with reduced side lobe interference.
Implementation Method 1
a processor may receive a thermal response of a material
Implementation Method 2
the processor may generate a first pulse compressed thermographic single pixel profile based on the reconstructed zero mean temperature
Data Source
AI summary
The present subject matter proposes a novel pulse compression favourable non-periodic thermal wave imaging that enhance the energy concentration capabilities and defect detection sensitivity and resolution in comparison with presently used pulse compression favourable thermal wave imaging approaches. This is due to most of the supplied energy is concentrated in the main lobe and very less energy will be redistributed to side lobes by the proposed Complimentary Golay coded excited thermal wave imaging.