[4A5] Investigation into modelling hydrogen-induced defects to predict their ultrasound images
L Chang, B Drinkwater and J Zhang
University of Bristol, UK
As hydrogen becomes central to global clean energy strategies, ensuring the safety of storage containers and pipelines is essential. Hydrogen-induced defects can form through various mechanisms, including embrittlement, blistering, hydrogen-induced cracking (HIC) and high-temperature hydrogen attack (HTHA). These defects often have irregular and complex geometries, posing significant challenges for both simulation and detection. In this paper, we investigate approaches for properly modelling hydrogen-induced crack geometries and predicting their signatures in ultrasound images. Statistical characteristics of various realistic hydrogen-induced defects are extracted and incorporated into crack profile simulations using a random walk algorithm. The resulting simulated crack profiles, such as linear, step-wise and branching cracks, are then implemented in finite element models to evaluate their acoustic backscattering behaviour and generate full matrix capture array datasets. Ultrasound images are reconstructed using the total focusing method imaging algorithm. Our results indicate that some fine details of crack geometry may not significantly affect the ultrasound image due to the limited operating frequency bandwidth commonly used in practice. This insight can help simplify defect modelling for more efficient and realistic ultrasound simulation.
