Laser-Induced Full-Matrix Ultrasonic Imaging of Complex-Shaped Objects

Area of Science:

• Non-destructive testing
• Ultrasonic imaging
• Laser ultrasonics

Background:

• Traditional ultrasonic inspection methods face limitations with complex geometries.
• Noncontact laser ultrasound offers advantages but requires advanced data processing for high-resolution imaging.

Purpose of the Study:

• To develop a laser-induced full-matrix imaging technique for complex-shaped objects.
• To combine laser ultrasound with the total focusing method (TFM) for enhanced imaging capabilities.
• To validate the technique through numerical simulations and experimental studies.

Main Methods:

• Acquired full-matrix data by synthesizing a laser ultrasonic array via alternate scanning of laser beams.
• Extracted surface Rayleigh waves for surface profiling and longitudinal waves for imaging.
• Utilized numerical simulations to analyze full-wave dynamics (generation, propagation, scattering).
• Adapted TFM to handle complex surfaces and suppress wave interferences.

Main Results:

• Successfully demonstrated laser-induced full-matrix imaging on complex-shaped objects.
• Achieved high-contrast imaging and accurate surface profiling.
• Numerical and experimental results on an aluminum sample showed good agreement, validating the method.

Conclusions:

• Laser-induced full-matrix imaging is a promising noncontact technique for inspecting complex geometries.
• The combination of laser ultrasound and TFM provides a powerful tool for material characterization.
• The method effectively suppresses interfering waves, improving imaging fidelity.