外文原文-使用磁致伸縮傳感器產(chǎn)生和探測扭轉(zhuǎn)導(dǎo)波

Generating and detecting torsional guided waves using magnetostrictive sensors of crossed coils Yi-Gon Kim a, Hong-Sik Moona, Kyung-Jo Parkb,n, Jeong-Ki Leec aDepartment of Electrical Engineering, Chonnam National University, San 96-1, Dundeok-dong, Yosu 550-749, Republic of Korea bDepartment of Mechanical Engineering, Chonnam National University, San 96-1, Dundeok-dong, Yosu 550-749, Republic of Korea cInnovation Center for Safety Diagnosis Technology of Heavy fax : +82 61 659 3229. E-mail address: kjpark40chonnam.ac.kr (K.-J. Park). NDT thus, the refl ection coeffi cient is calculated to be 0.005. The refl ection coeffi cients for notches CC3 and CC4 were similarly calculated to be 0.009 and 0.013, respectively. The results show that the amplitude is roughly a linear function of the circumferential extent of the notch. 5. Conclusions We developed a crossed-coil magnetostrictive sensor to gen- erate and detect torsional guided waves for pipe inspection and verifi ed the performance of the sensor through experiments. Fig. 8. Response measured using the crossed-coil MsS: (a) time history measured at the end, and (b) timefrequency representation of the measured signals. 1.2 1 0.8 0.6 AmplitudeV 0.4 0.2 0 0 Pre-magnetization Crossed Coils 0.8 Toroidal coil input currentA 1.8 Fig. 9. Measured amplitudes as a function of input current to toroidal coil. Y.-G. Kim et al. / NDT (2) excitation energies are used to generate the torsional waves only so that unwanted modes such as the L mode cannot be excited on the pipe. Results from a pipe with multiple circumferential notches showed that any defect larger than three times the pipe wall thickness in diameter was detected using the crossed-coil MsS. Therefore long-range guided wave testing techniques combined with a crossed-coil magnetostrictive sensor can be a useful and cost-effective tool for pipe inspection. Acknowledgments ThisstudywassupportedbytheMinistryofKnowledgeEconomy (MKE) and the Ministry of Education, Science, and Technology (MEST)throughtheRegionalInnovationCenterProgramandHuman Resource Training for Regional Innovation. References 1 Alleyne D, Lowe M, Cawley P. The refl ection of guided waves from circumfer- ential notches in pipes. J Appl Mech 1998;65:63541. 2 Ditri J. Utilization of guided elastic waves for the characterization of circumferential cracks in hollow cylinders. J Acoust Soc Am 1994;96: 376975. 3 Demma A, Cawley P, Lowe M, Roosenbrand A, Pavlakovic B. The refl ection of guided waves from notches in pipes: a guide for interpreting corrosion measurements. NDT and E Int 2004;37:16780. 4 Lee JH, Lee SJ. Application of laser-generated guided wave for evaluation of corrosion in carbon steel pipe. NDT and E Int 2009;42:2227. 5 Williams R. Theory of magnetostrictive dealy lines for pulse and continuous wave transmission. IEEE Trans Ultrason Eng 1959;UE-7:1638. 6 Kwun H. Method and apparatus generating and detecting torsional wave inspection of pipes or tubes. US Patent, Patent no. US 6429560 B1, 2002. 7 Park C, Han S, Cho S, Kim Y. The generation of torsional waves and the pipe diagnosisusingmagnetostrictivetransducers.ProcKNV2003:5448. in Korean. 8 Vinogradov A. Method and system for the generation of torsional guided wavesusingaferromagneticstripsensor.USPatent,Patentno.US7573261B1, 2009. 9 Gianola U. Application of the Wiedemann effect to the magnetostrictive coupling of crossed coils. J Appl Phys 1955;26:11527. 10 Alleyne D, Pavlakovic B, Lowe M, Cawley P. Rapid long range inspection of chemical plant pipework using guided waves. Insight 2001;43:936. 11 Alleyne D, Lowe M, CawleyP. The mode conversion of a guided wave by a part- circumferential notch in a pipe. J Appl Mech 1998;65:64956. 12 Rose J.