Development of ultrasonic technique using phased array probes in type IV low-pressure tank
Paulina Kozera, Łukasz Sarniak, Kamil Dydek, Andrzej Wolanin, Anna Boczkowska
Quarterly No. 4, 2025 pages 234-242
DOI: https://doi.org/10.62753/ctp.2025.04.4.4
keywords: ultrasonic testing, phased array, attenuation, delamination, defects, composite tank, liner, GFRP, numerical simulations
abstract The aim of this work is to develop an ultrasonic technique employing phased array probes to detect structural defects in type IV low-pressure tanks used for the storage of hazardous chemicals. Ultrasonic testing was performed by means of an OmniScan MX2 phased-array ultrasonic flaw detector with appropriate probes, and numerical simulations were conducted utilizing CIVA software. Attenuation coefficients were measured for a composite layer excised from a two-layer low-pressure tank. Based on these results, a centre frequency of 5 MHz was selected as optimal. The determined parameters, such as the attenuation coefficient and the structural noise level, were implemented in the CIVA model. The detection criteria were established and color-coded: defects with a signal-to-noise ratio (SNR) < 0 dB were labelled white (undetectable); those 0–10 dB were labelled yellow (limited detectability); and those > 10 dB were labelled green (optimal detectability). The simulation results were validated by testing the composite samples with polytetrafluoroethylene (PTFE) inserts of varying sizes and depths. The defect detectability determined from the simulations was consistent with that obtained from testing reference samples.