Simulation And Analysis Of Electromagnetic Acoustic Transducer Mechanism

Distinguished from Piezoelectric ultrasonic testing technology, electromagnetic acoustic technology has many advantages, such as inspection without coupling agent, stimulated different mode wave easily and so on, attracts attention highly in Nondestructive Testing field. Because of complexity and diversity of the electromagnetic acoustic transducer, apply ANSYS to simulate and analyze it based on study and understanding of electromagnetic acoustic transducer mechanism at home and abroad.Analyze electromagnetic acoustic transducer mechanism divided into three intercoupling fields as electromagnetic field, kinetic field and ultrasonic field with detailed mathematical description. Based on various configuration of magnet and winding coil in electromagnetic acoustic transducer, analyze different mode wave stimulated by them correspondingly and sound transmission in sample.Apply ANSYS to simulate and analyze electromagnetic field of the electromagnetic acoustic transducer. Based on the established three-dimensional finite element model of electromagnetic acoustic transducer, acquisition eddy current, Lorentz force on the surface of the sample. At the same time, by means of which electromagnetic field intercoupling with structure force field, acquisition stress, strain and displacement distribution in the sample to analyze further acoustic field of the electromagnetic acoustic transducer in the sample. The weakness of electromagnetic acoustic transducer is low transduction efficiency resulting in weak signal. In order to improving transduction efficiency, optimize it including Lift-off distance between coil and sample, parameter of magnet and coil.By means of which electromagnetic field intercoupling with structure force field, obtain the orientation of radiated sound field of electromagnetic ultrasonic surface wave, its variation with thickness of sample and stimulated current frequency. Orientation result is verified by experiments. At last, compared radiated sound fields of three configuration of magnet and winding coil in electromagnetic acoustic transducer with each other.