Abstract
As indispensable parts of the tanks for oil and chemical storage and transportation, the tank floors have stringent nondestructive testing requirements owing to their severe operating conditions. In this article, a synthetic aperture focusing technology method is proposed for the circumferential scanning of the tank floor outside the tank using ultrasonic guided waves. The magnetostrictive patch transducer (MPT) is designed and manufactured for the generation and receiving of the SH0 mode. Based on the exploding reflector model (ERM), the relationships between guided wave fields at different radii of polar coordinates are derived in the frequency domain. The defect spot is focused when the sound field is calculated at the radius of the defect. Experimental validations are performed for the defect inspection in an iron plate. The angular bandwidth of the defect spot is used as an index for the angular resolution. The results of the proposed method show significant improvement compared to those obtained by the B-scan method, and it is found to be superior to the conventional method—named delay and sum (DAS) in both angular resolution and calculation efficiency.
How to Cite:
Wu, J. ., Tang, Z. ., Lv, F. . & Yang, K. ., (2019) “Circumferential scanning imaging of tank floors using ultrasonic guided waves”, Review of Progress in Quantitative Nondestructive Evaluation .
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