Sensitivity of Ultrasonic Coda Wave Interferometry to Material Damage-Observations from a Virtual Concrete Lab

Area of Science:

• Civil Engineering
• Materials Science
• Geophysics

Background:

• Ultrasonic measurements are vital for structural health monitoring of concrete.
• The coda of ultrasonic waves is sensitive to material changes.
• Coda Wave Interferometry (CWI) quantifies velocity changes in concrete.

Purpose of the Study:

• To numerically investigate CWI's sensitivity to concrete mesostructures and damage.
• To assess CWI's potential for detecting localized and global damage in concrete.

Main Methods:

• Generation of realistic numerical concrete models.
• Simulation of damage evolution using the discrete element method.
• Numerical propagation and recording of ultrasonic wavefields.

Main Results:

• Different damage scenarios produced distinct waveform decorrelation slopes.
• CWI's sensitivity to varying concrete mesostructures and damage levels was demonstrated.
• Correlation between waveform decorrelation and material velocity reduction was observed.

Conclusions:

• CWI shows potential for effective structural health monitoring of concrete infrastructures.
• Findings provide recommendations for applying CWI at a structural scale.
• Numerical simulations offer insights into CWI's application in concrete.