Three-dimensional reconstruction of subsurface defects using finite-difference modeling on pulsed thermography

Area of Science:

• Non-destructive testing
• Thermal analysis
• Materials science

Background:

• Pulsed thermography is a non-destructive evaluation technique used for detecting subsurface defects.
• Analyzing thermal response data from pulsed thermography videos can be complex.
• Accurate reconstruction of defect geometry is crucial for material integrity assessment.

Purpose of the Study:

• To develop an advanced technique for analyzing pulsed thermography videos.
• To enable the detection and precise reconstruction of subsurface defects in various materials.
• To provide an interpretable method for visualizing defect characteristics.

Main Methods:

• Analysis of thermal response in pulsed thermography videos.
• Comparison of experimental thermal data with a finite-difference model.
• Systematic adjustment of the model to minimize a cost function.
• Derivation of depth and thickness functions for defect characterization.

Main Results:

• Successful detection and 3D reconstruction of subsurface defects.
• Accurate determination of defect shape, size, depth, and location.
• Generation of easily interpretable graphical representations of detected defects.
• Validation of the technique for both homogeneous and layered objects.

Conclusions:

• The developed technique offers a reliable method for subsurface defect analysis using pulsed thermography.
• The approach provides quantitative information about defect geometry.
• This method enhances the capabilities of non-destructive evaluation for material inspection.