Transient Electromagnetic-Thermal Nondestructive Testing

PrefaceAcknowledgments1. Nondestructive Testing and Transient Electromagnetic-Thermal NDTPart I: Pulsed Eddy Current2. Magnetic Sensor Based Pulsed Eddy Current for Defect Detection and Characterization2.1 Introduction to PEC 52.2 Magnetic Sensor-based PEC Systems2.2.1 Electronics Design2.2.1 Probe Design2.3 Signal Processing Software2.3.1 Signal Feature Extractions2.3.2 PCA-based Feature Extraction2.3.3 Wavelet-based PCA2.4 Inspection of Non-ferromagnetic Samples2.4.1 Sample Thickness Measurement2.4.2 Inspection of Surface Discontinuities2.4.3 Inspection of Sub-surface Discontinuities2.4.4 Flaw Classification and Quantification2.5 Inspection of Ferromagnetic Samples2.5.1 PEC and Magnetic Saturation2.5.2 Penetration Depth Test2.5.3 Inspection of Surface and Sub-surface Defects3. Hall Based PEC Features for Material Properties Evaluation and Defect Detection3.1 Features Extraction in Time Domain3.2 Stress Measurement Using Time Domain Features3.3 Corrosion Evaluation and Development Prediction3.4 Scanning PEC for Honeycomb Evaluation3.5 Scanning PEC for CFRP Impact Evaluation4. Coil-Based Rectangular PEC Sensor for Defect Classification4.1 Rectangular PEC Sensor and Feature Extraction4.2 Defect Classification under Different Directions4.3 Defect Classification under Variation of Lift-offs4.4 PCA with Frequency Domain Responses for Defect Classification in Multi-layer Structures4.4.1 Methods of PCA with Frequency Response4.4.2 Defect Classification Results with Various Air Gaps4.4.3 Defect Classification Results under Varying Lift-offs4.5 PCA-Support Vector Machine Based Defect Classification4.5.1 Methods of SVM Based Classification4.5.2 Classification resultsPart II: Transient Eddy Current Thermography5. Active Thermography and Eddy Current Excited Thermography5.1 Active Thermography5.2 Eddy Current Thermography5.2.2 Physical Principle of ECPT5.2.3 Surface Heating and Volumetric Heating of ECPT5.2.4 Feature Extraction Methods of ECPT5.3 ECPT for Quantitative Analysis of Surface Defects5.3.1 Quantitative Analysis Strategy5.3.2 Results and Validation6. Heat Conduction Based Eddy Current Pulsed Thermography (ECPT) for Defect Evaluation6.1 Time Domain Quantification Analysis for Deep Defects6.1.1 Analytical Solutions6.1.2 Numerical Studies6.1.3 Experimental Studies6.2 Log Domains Quantification Analysis for Deep Defects6.2.1 Methodology6.2.2 Numerical Studies6.2.3 Experimental Studies6.3 Lateral Heat Conduction Based Defect Evaluation6.3.1 Methodology6.3.2 Numerical Studies6.3.3 Experimental Studies6.3.4 Rail Crack Evaluation7. Eddy Current Step or Time-resolved Thermography (ECST)7.1 Principle of ECST7.2 Numerical Studies7.3 Experimental Studies8. Eddy Current Pulsed Phase Thermography (ECPPT) for Metal Materials Evaluation8.1 Basic Theory of ECPPT8.2 Finite Element Analysis for Defect Quantification8.3 Experimental Studies for Defect Quantification8.4 Elimination of Surface Emissivity Variation9. Volume or Inside Heating Eddy Current Thermography9.1 Physical Principles of SHT and VHT9.1.1 Surface Heating Thermography9.1.2 Volume Heating Thermography and Inside Heating Thermography9.2 Numerical Studies9.3 Experimental Studies10. Volume Heating ECT and Phase Analysis for CFRP Evaluation10.1 Methodology of ECVHT and Phase Analysis10.2 Delamination Evaluation Using Volume Heating ECPPT10.3 Impact Evaluation Using Eddy Current Square Pulse Phase Thermography10.3.1 Methodology of ECSPPT10.3.2 Experimental Studies11. Pulsed Inductive Thermal Wave Radar (PITWR)11.1 Theory of TWR11.2 Subsurface Defect Evaluation and Suppression of Emissivity Variation in Steel11.2.1 Simulation Results for Depth Quantification11.2.2 Experimental Studies of Steel11.3 Experimental Studies of CFRP11.3.1 Improvement of Delamination Detectability in CFRP11.3.2 Improvement of Impact Detectability in CFRP12. Through Coating Imaging of Early Marine Corrosion Using ECPPT12.1 Steel Corrosion Detection and Evaluation12.2 Methodologies12.3 Experimental StudiesPart III: Physical-Mathematical Model Based ECPT for Defect Evaluation13. Separations of ECPT Transient Electromagnetic Thermal Fields13.1 Demand for Separation of Transient Electromagnetic Thermal Fields13.2 Physical-mathematical Time-dependent Partition Model13.3 Validation of Model: Simulation and Experiments13.3.1 Simulation and Experimental Set-up13.3.2 Results and Discussion14. Unsupervised Sparse Pattern Diagnostic of Defects with ECPT14.1 Methodology14.2 Physics-Based Data Analytics14.3 Experiment Studies14.4 Results and Discussion15. Multi-dimensional Tensor-based ECPT for Wind Turbine Gear Inspection15.1 NDT, CM and SHM of Wind Turbine15.2 Methodology15.3 Experimental Studies15.3.1 ECPT and Tensor15.3.2 Validation Study by Using Barkhausen Noise15.3.3 Advantages and Limits16. Physics-based Modeling and Pattern Mining of ECPT16.1 Methodology16.2 Modeling and Mining of Thermal Patterns in Spatial-Time, Frequency and Sparse domains16.3 Results and DiscussionReferences