The Electro-Magnetic Acoustic Transducer (EMAT) consisting of magnets and coil can transmit and receive ultrasonic waves without contact to the specimen. So, it is expected to be used for remote testin g/monitoring of structures in severe condition. This paper discusses techniques of ultrasonic flaw detecting suitable for EMAT, e.g., waveform processing of the received signal and ultrasonic imaging t echnique. We next evaluate the characteristics of a self-produced Lorenz type EMAT such as the amplitude di...
英字タイトル:
Visualization of Defects by Self-produced Electro-Magnetic Acoustic Transducer

This paper studies the resolution of defects by a Lorenz type of Electro-Magnetic Acoustic Transducer on the basis of simulation of ultrasonic imag ing. Transmission and reception processes and propagation of induced ultrasonic wave are formulated and numerically solved by FEM and FDM. It is sh own that the smallest defect with the size of the special division of FDM can be detected from the ultrasonic image using ALOK method. It is also shown from similarity rules that the resolution of defects becomes 1...
英字タイトル:
Resolution of searching defects by electromagnetic acoustic transducer