Technology of Damage Imaging of the Steel Plate-like Structure Based on EMAT
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摘要: 采用基于tEP的正交匹配信号处理方法,结合时间反转理论,进行钢板结构损伤的成像研究.首先利用电磁超声换能器(EMAT)在钢板上激励并接收兰姆波,运用匹配追踪算法对接收的原始信号进行处理,以改善信号质量;然后对钢板损伤前后的信号做代数差,并结合时间反转理论,获得时间反转信号.最后,将时间反转信号按照合成成像原理进行损伤成像.试验表明:该方法可以精确提取信号的包络,较为准确地监测出缺陷的位置、范围等特征.Abstract: The paper researches the damage imaging of the steel plate-like structure by using orthogonal matching pursuit based on tEP and the theory of time reverse.At first the electromagnetic acoustic transducer (EMAT) is used to excite and receive Lamb wave on the plate,the signal is processed with matching pursuit algorithm to improve signal quality;Then the algebraic difference is performed for the signals and a set of time reversal signal are obtained by combining with time reverse theory;Finally,damage imaging is realized in accordance with the principle of synthetic imaging.Experiments show that this method can extract the envelope signal precisely and accurately monitor the defect features.
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Keywords:
- EMAT /
- Orthogonal matching pursuit /
- Time reverse /
- Lamb wave
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