Simulation of ultrasonic inspection of concrete using finite elements and analytical models

Ultrasonic non-destructive testing (NDT) simulation plays a key role in the evaluation of concrete structures. Concrete is a dense composite medium whose heterogeneities (aggregates, porosity, micro cracks) cause wave dispersion and attenuation, thus affecting inspection techniques. Classical approaches rely on the study of the coherent wave, characterized by its phase velocity and attenuation. Since 3D numerical models are too computationally expensive, improving existing simplified analytical models is essential. This study proposes a new 2D homogenization model better suited for dense media. The improvement lies in a more accurate description in analytical models of the pair-correlation function of aggregate positions. The new model is compared to a 2D finite elements code integrated in CIVA NDT simulation platform. Results show good agreement between the developed analytical model and numerical simulations. Further work will explore the effects of aggregate granulometry and other material configurations to ultimately extend the model to 3D and improve ultrasonic simulation accuracy for concrete.