In conventional electromagnetic acoustic transducer(EMAT),permanent magnets are difficult to apply to actual situations and the signal amplitude is small.According to the complementarity of EMAT and eddy current testing(ECT)in detection range,a pulsed EMAT-ECT composite sensor structure is designed.The multi-physics field coupling technique is conducted to verify the feasibility of the composite detection method and the key parameters affecting detecting sensitivity of the sensor are discussed.The results suggest the composite sensor can excite the eddy current signal for detecting surface defects and the ultrasonic signal for detecting deep layer defects which possess good sensitivity to defects of different widths and depths.In addition,the parameters of excitation coil and eddy current coil are optimized,which provides an idea for the application of electromagnetic ultrasonic and eddy current composite testing.
关键词
无损检测/脉冲电磁体/电磁超声/涡流
Key words
nondestructive testing(NDT)/pulsed electromagnet/electromagnetic ultrasonic/eddy current