| Title |
Characteristic Analysis of Electromagnetic-ultrasonic Guided Waves for Defect Signals in Condenser Tubes |
| Authors |
Sang-Hoon Choi ; Gi-Nam Wang |
| DOI |
http://dx.doi.org/10.6110/KJACR.2015.27.3.174 |
| Keywords |
유도 초음파 ; 복수기 전열관 ; 자왜형 센서 ; 주파수 Guided Wave ; Condenser Tube ; Magnetostrictive Sensor ; Frequency |
| Abstract |
This paper describes a signal processing technique for identifying signals from defects by using an electromagneticultrasonic guided waves method based on a magnetostrictive sensor that generates a torsional mode (T(0, 1)). Because this technique is based on the digital filtering, the filtered signals provide information on the relationship between the cutoff frequency of band-pass filter and the characteristic of defect signals in heat exchange tubes. To verify the performance of the technique, artificial defects with various thickness reduction ration and shape were machined in titanium tubes, and digital filtering results are reported. The results show that digital filtering provides information to the identify shape of defects and the contact condition between the tube and support ring. Therefore, the proposed technique has good potential as a tool for evaluating the integrity of heat exchange tubes. |