Rail Crack Monitoring Using Acoustic Emission Technique
In: Springer Theses Ser.
Intro -- Supervisor's Foreword -- Parts of this thesis have been published in the following journal articles:Li, D. *, Kuang, K. S. C., Koh, C. G. (2017). Rail crack monitoring based on Tsallis synchrosqueezed wavelet entropy of acoustic emission signals: a field study. Structural Health Monitoring. Prepublished online December 4, 2017, DOI: 10.1177/1475921717742339.Li, D., Kuang, K. S. C. *, Koh, C. G. (2017). Fatigue crack sizing in rail steel using crack closure-induced acoustic emission waves. Measurement Science and Technol -- Acknowledgements -- Contents -- Abbreviations -- Nomenclature -- List of Figures -- List of Tables -- Summary -- 1 Introduction -- 1.1 Background -- 1.2 Objectives and Scope of Research -- 1.3 Research Significance -- 1.4 Thesis Outline -- References -- 2 Literature Review -- 2.1 Common Defects of Rail Track -- 2.1.1 Surface Cracks -- 2.1.2 Internal Cracks -- 2.2 Current Rail Monitoring Techniques -- 2.2.1 Acceleration-Based Technique -- 2.2.2 Automated Visual Technique -- 2.2.3 Ultrasonic Techniques -- 2.2.4 Electromagnetic Techniques -- 2.2.5 Magnetic Induction Technique -- 2.3 AE Technique and Its Applications -- 2.3.1 Introduction to AE Technique -- 2.3.2 Characterization of AE Waves -- 2.3.3 Relevant Applications of AE Technique -- 2.4 State-of-Art of Rail Condition Monitoring Using AE -- References -- 3 Propagation Features and Source Location -- 3.1 Introduction -- 3.2 Experimental Procedure -- 3.2.1 Pencil Lead Break (PLB) -- 3.2.2 Field PLB Test -- 3.2.3 Field Train Pass-by Test -- 3.2.4 AE Data Acquisition -- 3.3 Time-Frequency Representation of AE Waves -- 3.3.1 Continuous Wavelet Transform (CWT) -- 3.3.2 Optimal Mother Wavelet Selection -- 3.3.3 Time-Frequency Characteristics of AE Waves -- 3.4 Propagation Features of AE Waves -- 3.4.1 Theory of Ultrasonic Propagation.
