Detection of defects in a 2D fluid-solid periodic cluster

• Published in: Ultrasonics 2021-04, Vol.112, p.106307-106307, Article 106307
• Main Authors: Hafidi Alaoui, Hamza, Rodriguez, Samuel, Deschamps, Marc
• Format: Article
• Language: English
• Subjects: Acoustics; Engineering Sciences; Heterogeneous medium; Multiple scattering; Nondestructive testing; Periodic cluster; Topological imaging; Ultrasonic waves
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2020.106307

•Topological imaging allows locating a defect buried in a periodic cluster.•Topological imaging takes advantage of medium heterogeneity to enhance resolution.•An imaging function adapted to fluid-solid heterogeneous media is proposed.•Classical imaging methods are retrieved from the topological imaging framework. The present work deals with locating a defect buried in a medium composed of a fluid matrix and small solid inhomogeneities. Classical imaging methods are based on delay and sum principle and would implicitly assume that the undamaged medium is homogeneous. The topological imaging framework however allows to take into account the heterogeneous nature of the undamaged medium and potentially to take advantage of it. In this work, it is applied to a demanding test case with different assumptions on the knowledge of the medium properties using a specifically-designed fluid-solid compatible imaging function. It leads to the definition of three imaging processes whose results are compared using respectively synthetic and experimental data. The results show the relevance of using the inhomogeneities’ locations information, but not necessarily at all steps of the imaging process, leading to the definition of so called hybrid topological imaging method.