| Title |
Active Lamb Wave Propagation-based Structural Health Monitoring for Steel Plate |
| Keywords |
SHM;lamb wave;gabor wavelet transform;pitch-catch;damage monitoring polygon;구조물 건전성 모니터링;램파;가보 웨이블릿;손상모니터링다각형 |
| Abstract |
This paper is the study on the verification of structural health monitoring (SHM) algorithm based on the ultrasonic guided wave. An active inspection system using Lamb wave (LW) for SHM was considered. The basic study about the application of this algorithm was performed for detecting the circular notch defect in steel plate. LW testing technique, pitch-catch method, was used for interpretation of circular notch defect with depth of 50% of plate thickness and 7 ㎜ width. Damage characterization takes place by comparing S? mode sensor signals collected before and after the damage event. By subtracting the signals of both conditions from each other, a scatter signal is produced which can be used for damage localization. The continuous Gabor wavelet transform is used to attain the time between the arrivals of the scatter and sensor signals. A new practical damage monitoring algorithm, based on damage monitoring polygon and pitch-catch method, has been proposed and verified with good accuracy. The possible damage location can be estimated by the average on calculated location points and the damage extent by the standard deviation. |