The Numerical Simulation Method for Electromagnetic Acoustic Technique

As no physical contact is necessary between the transducer and test-piece, the electromagnetic acoustic technique(EMAT) can not only improve the inspection efficiency but also extend the application area of ultrasonic NDT to the fields of a high temperature, a high speed and on-line inspection. A finite element method for the numerical simulation of electromagnetic ultrasonic testing signals was established and the corresponding numerical code was developed. In order to prove the validity of the code, propagation behaviors of ultrasonic waves excited by transducers of different structure were investigated by using the developed code. The simulation method and code provided a useful tool for the defect sizing and transducer optimization in practical application of EMAT.