Ultrasonic wave propagation in heterogeneous solid media: theoretical analysis and experimental validation

Area of Science:

• Materials Science
• Civil Engineering
• Acoustics

Background:

• Thermal damage in concrete causes microcracks, altering material properties.
• Ultrasonic wave scattering occurs in heterogeneous, damaged concrete.
• Understanding wave propagation is crucial for non-destructive evaluation.

Purpose of the Study:

• To develop and validate a homogenization model for ultrasonic wave propagation in thermally damaged concrete.
• To characterize the effects of microcracks on wave velocity and attenuation.
• To correlate theoretical predictions with experimental measurements.

Main Methods:

• A homogenization model integrating multiple wave scattering was employed.
• Simulations were performed for concrete-specific scenarios.
• Experimental validation involved immersion measurements of phase velocity and attenuation from 160 kHz to 1.3 MHz.

Main Results:

• The model successfully predicts phase velocity and attenuation based on material composition and damage.
• Experimental results validated the model's predictions for phase velocity in simulated damaged concrete.
• Qualitative agreement was observed for velocity and attenuation changes in thermally damaged concrete.

Conclusions:

• The homogenization model effectively characterizes ultrasonic wave behavior in damaged concrete.
• Ultrasonic testing provides a viable method for assessing thermal damage in concrete structures.
• Further research can refine the model for quantitative damage assessment.