Recent train accidents have reaffirmed the need for developing rail defect detection systems that are more effective than those used today. One of the recent developments in rail inspection is the use of ultrasonicguided waves (UGWs) and non-contact probing techniques to target transverse-type defects. Besides theobvious advantages of non-contact probing, that include robustness and a potential for large inspectionspeed, such a system can theoretically detect transverse defects under horizontal shelling or head checks.This paper demonstrates the effectiveness of digital signal processing to enhance the damage detectionsensitivity of the non-contact system. The method proposed here combines the advantages of UGWinspection with the outcomes of the Discrete Wavelet Transform (DWT) that is used for extracting robustdefect-sensitive features. In particular, the DWT is exploited to de-noise the ultrasonic signals in real-timeand generate a set of relevant wavelet coefficients to construct a uni-dimensional damage index. Thegeneral framework proposed in this paper is applied to the detection of crack-like and internal defects in arailroad track mock-up built at UCSD. The proposed signal analysis approach is general and is applicableto many other structural monitoring applications using UGWs as the main defect diagnosis tool.
|Numero di pagine||6|
|Stato di pubblicazione||Published - 2007|
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry