Vol.2 No.4 GA 16 - AA 30 - SP5 ( 31 - 32 - 33 ) - NT 33 - 34 - 35 Vol.3 No.2 | |||||
Academic Articles | |||||
Regular Paper (invited) | Vol.3, No.1 (2011) p.11 - p.24 | ||||
Simulation of Ultrasonic Fields and Echoes Obtained Using Angle Beam Transducer by Hybrid FDTD Method |
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Tomonori KIMURA1,* and Shusou WADAKA2 | |||||
1 Mitsubishi Electric Corporation, 5-1-1 Ofuna, Kamakura, Kanagawa 247-8501, Japan 2 Ryoden Shonan Electronics Corporation, 25, Yamasaki, Kamakura, Kanagawa 247-0066, Japan (Received; For the use of JSM)
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Abstract | |||||
A hybrid model to calculate an ultrasonic field and a received signal by the angle beam technique is presented. In this model, the field in a test object transmitted by an angle beam transducer is calculated using the Rayleigh integral with the geometrical optics approximation, and the field scattered by a flaw is calculated by the finite-difference time domain (FDTD) method. The signal received by the transducer is obtained by calculating the inner product of the transmitted field and the scattered field at each grid point used in the FDTD method, and then these products are integrated over a predetermined calculation area. Since the calculation area in the FDTD method can be limited to around the flaw, the calculation time and computer memory required can be reduced. In the angle beam technique, the transmission coefficient from a couplant to a test object becomes complex when the angle of incidence exceeds the critical angle. In order to calculate the transmitted field in this case, an analytic signal is introduced to deal with the complex transmission coefficient. The validity of the model is demonstrated by experiments using an angle beam transducer and a steel block with a side-drilled hole. | |||||
Keywords | |||||
Ultrasonic waves, Nondestructive testing, Simulation model, Hybrid FDTD method, Angle beam technique | |||||
Full Paper: PDF
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