Foreword ..................................................... xiii
Preface ........................................................ xv
List of Figures ............................................... xxi
List of Tables ............................................... xxxi
1 Introduction ............................................... 1
1.1 General Characteristic of Nondestructive Testing (NDT)
Methods .................................................... 1
1.2 Ultrasonic Wave Type Overview .............................. 6
2 Introduction to Search Unit Design ........................ 13
2.1 Principles of Search Unit Design .......................... 13
2.1.1 Basic Types of Ultrasonic Search Units ............. 13
2.1.2 Essential Facts about Ultrasonic Wave Propagation .. 17
2.1.3 Basic Considerations for Delay Line and Wedge
Design ............................................. 20
Delay Line for Straight Beam Probes
(Figure 2.5) ....................................... 20
Wedge for Angle Beam Probe ......................... 23
2.1.4 Examples of Probe Design for Automated Inspection .. 25
2.1.5 Wedge Design for Surface Wave Probe ................ 27
2.2 Considerations for Transducer Selection ................... 32
2.2.1 Basics of Transducer Design ........................ 32
Matching Layer ............................................ 33
Backing ............................................ 34
Tuning Components .................................. 35
2.2.2 Acoustic Properties of Crystal Materials ........... 35
2.2.3 Velocity Measurement in Metals ..................... 38
Bulk Velocity Measurement in Thick
Metal .............................................. 38
Bulk Velocity Measurement Using a Thin Metal
Strip .............................................. 39
2.2.4 Velocity and Attenuation Measurement in Wedge
Materials .......................................... 42
Velocity Measurement in Wedge Materials ............ 42
Attenuation Measurement in Wedge Materials ......... 45
2.2.5 Crystal Size Selection ............................. 52
2.3 Calculation of Straight Beam Transducer Directional
Characteristic ............................................ 57
2.3.1 Acoustic Field of a Straight Beam Transducer ....... 57
2.3.2 Angle of Divergence Calculation .................... 60
2.3.3 Main Lobe Profile Calculation of a Round Crystal
in Far Field ....................................... 62
2.3.4 Coefficient К Calculation at Any Decibel Level ..... 63
3 Single Angle Beam Probe Design ............................ 65
3.1 Basics of Probe Design .................................... 65
3.2 Considerations Related to the Practical Concept of Wedge
Design .................................................... 67
3.3 Measurement of Refracted Angles ........................... 69
3.4 Deviation of Refracted Angle Related to Thick Wall Test
Object Inspection ......................................... 73
4 Dual Straight and Angle Beam Probe Design ................. 77
4.1 Principles of Dual Straight Beam Probe Design ............. 77
4.2 Sequence of Wedge Calculation ............................. 78
4.3 Sensitivity Curves ........................................ 81
4.4 Example of Dual Straight Beam Probe Design ................ 82
4.5 Basics of Dual Angle Beam Probe Design .................... 86
4.6 Wedge Conceptual Design ................................... 87
4.7 Wedge Design for Inspection of a Test Object with Flat
and Parallel Surfaces ..................................... 88
4.7.1 The Wedge Calculation for the Inspection of Test
Objects with Flat and Parallel Surfaces ............ 91
4.8 Wedge Design for the Inspection of a Test Object with
a Curved Surface .......................................... 92
4.8.1 Wedge Calculation for the Inspection of a Test
Object with Concentric Surfaces .................... 92
The Case of Axial Direction of Beam Propagation .... 92
The Case of Circumferential Direction of Beam
Propagation ........................................ 93
5 Multiple Crystal Probe Design ............................. 99
5.1 Concept of "Packaging," ................................... 99
5.1.1 Triplex Probes .................................... 100
5.1.2 Dual Duplex Angle Beam Probes ..................... 101
5.1.3 Five Crystal Assemblies Probe ..................... 102
5.2 Example of Triplex Probe Design .......................... 103
5.2.1 Requirements for Triplex Probe Design ............. 103
5.2.2 Wedge Design for 60°S Refracted Angle ............. 104
5.2.3 Wedge Design for 45°S Refracted Angle ............. 106
5.2.4 Dual Straight Beam Probe Design as Portion of
Triplex Probe ..................................... 107
6 Technique Development and Probe Design for TOFD Method
Application .............................................. 111
6.1 Introduction to Techniques Based on Diffraction
Phenomena ................................................ 111
6.2 TOFD Forward Scattering Technique ........................ 113
6.2.1 Flat Surface Test Object Inspection ............... 115
6.2.2 Curved Surface Test Object Inspection
(Figure 6.5) ...................................... 117
6.3 Examples of Probe Calculation for Curved Surface Test
Object Inspection ........................................ 118
6.3.1 Axial Crack Detection and Sizing .................. 118
6.3.2 Circumferential Crack Detection and Sizing
(Figure 6.7) ...................................... 120
6.3.3 Probe Design ...................................... 121
6.3.4 Comments .......................................... 122
6.4 Probe Design for TOFD Back Scattering Technique .......... 123
6.4.1 Basics of TOFD Back Scattering Technique .......... 123
6.4.2 Examples of Tandem Probe Design ................... 127
6.4.3 Gliding Diffracted Waves Technique ................ 133
7 Technique Development and Probe Design for Cylindrical
Rod Inspection ........................................... 135
7.1 Boundary Effect .......................................... 135
7.2 Symmetric and Asymmetric Cylindrical Rod-Guided Waves .... 136
7.3 Technique Development and Probe Design for Inspection
of Stepped Shaft ......................................... 140
7.4 Technique Development and Probe Design for Stud
Inspection ............................................... 144
7.4.1 Stud Inspection from the Top Surface .............. 144
7.4.2 Stud Inspection from a Center-Drilled Bore ........ 148
7.5 Notch Dimension Calculation for Stud Calibration
Standards ................................................ 157
8 Technique Development and Probe Design for Hollow
Cylinder Inspection ...................................... 163
8.1 Lamb Wave Generation ..................................... 163
8.1.1 Phase and Group Velocities ........................ 167
8.1.2 Lamb Wave Propagation Parameters .................. 170
Selection of the Best Modes and Frequencies ....... 173
Lamb Wave Attenuation ............................. 174
Reflected Signal Shape ............................ 175
8.2 Technique Development and Probe Design for the
Inspection of Hollow Cylinders from the Inside Surface ... 176
8.2.1 Test Object Description and Inspection
Consideration ..................................... 176
8.2.2 Lamb-Type Guided Wave Mode Selection for
Practical Application ............................. 182
8.3 Technique Development and Probe Design for the
Inspection of Hollow Cylinders from the Outside Surface .. 184
8.3.1 Technique Development and Probe Design for
Inspection of Cylinders with Welded Adapters ...... 184
Test Object Description and Inspection
Consideration ..................................... 184
Selection of the Best Modes and Frequencies ....... 186
Group Velocity Measurement ........................ 189
8.3.2 Technique Development and Probe Design for
Heater Sleeve Inspection .......................... 192
Test Object Description and Inspection
Consideration ..................................... 192
Lamb-Type Guided Wave Mode Selection .............. 195
Experiments to Measure Wave Propagation
Parameters ........................................ 196
8.3.3 Technique Development and Probe Design for
a Thick Wall Hollow Cylinder Inspection ........... 204
Test Object Description ........................... 204
Mode Selection for Transducers with Standard
Frequencies ....................................... 208
Energy Distribution along the Hollow Cylinder ..... 213
Influence of Water Gap Thickness on Wave
Propagation for S0 Mode ........................... 215
Rayleigh Wave Velocity Measurement ................ 216
9 Technique Development and Focused Probe Design for
Immersion Method Inspection .............................. 219
9.1 Basics of Focused Immersion Probe Design ................. 219
9.1.1 General Observation ............................... 219
9.1.2 Consideration Relative to Straight Beam
Immersion Focused Probe Design .................... 221
Spherical Aberrations Phenomenon .................. 221
9.1.3 Acoustic Parameters of Focused Probe .............. 223
9.2 Geometric and Acoustic Parameter Calculation ............. 224
9.3 Straight Beam Spherical Focused Probe Design ............. 226
9.3.1 Assessment of Design Feasibility .................. 226
9.3.2 Consequence of Calculation ........................ 228
9.3.3 Example of Focused Immersion Probe Calculation
with a Single-Surface Lens ........................ 231
10 Technique Development and Probe Design for Reactor
Pressure Vessel Nozzle Inner Radius Inspection ........... 237
10.1 Inspection Zone Configuration ............................ 237
10.2 Inspection from the Outside Nozzle Surfaces: Contact
Method ................................................... 238
10.3 Example of Wedge Design for Inner Radius Inspection
from the Outer Surface ................................... 240
10.4 Inspection from the Inside Nozzle Surface: Immersion
Method ................................................... 243
11 Search Unit Functioning Test ............................. 247
11.1 Evaluation of Certain Characteristics of a Search Unit ... 247
11.1.1. Definition and Examples of Bandwidth ............. 248
11.2 Measurement of Specific Parameters of Selected Search
Units .................................................... 250
11.2.1 IIW Reference Blocks .............................. 251
11.2.2 Additional Test Blocks ............................ 253
Appendix A System of Units and Symbols That Are Accepted for
This Book ................................................ 257
Appendix В American Societies Engaged in Activities Related
to Nondestructive Testing and Serving the Needs of
NDT Professionals ........................................ 261
Appendix С An Example of Applying the Third Critical Angle .... 265
Appendix D WesDyne International Computer Program for Lamb
Wave Dispersion Curve Calculation ........................ 267
Glossary of Terms Specific to This Book ....................... 273
Bibliography .................................................. 279
About the Author .............................................. 283
Index ......................................................... 285
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