Contents
1. Electrical Resistance Strain Gages
1.1 Introduction
1.2 Basic Principle
1.3 Bonded Resistance Strain Gages
1.4 Transverse Sensitivity and Gage Factor
1.5 Electrical Circuits
1.5.1 Introduction
1.5.2 The potentiometer Circuit
1.5.3The Wheatstone Bridge
1.6 Strain Gage Rosettes
2. Fundamentals of optics
2.1 Introduction
2.2 Historical Overview
2.3 Light Sources, Wave Fronts, and Rays
2.4 Reflection and Mirrors
2.4.1 Reflection
2.4.2 Plane Mirrors
2.4.3 Spherical Mirrors
2.5 Refraction
2.6 Thin Lenses
2.7 The Wave Nature of light - Huygens' Principle
2.8 Electromagnetic Theory of Light
2.9 Polarization
2.10 Interference
2.10.1 Introduction
2.10.2 Interference of Two Linearly Polarized Beams
2.10.3 Young's Double-Slit Experiment
2.10.4 Multi-slit interference
2.10.5 Interference of Two Plane Waves
2.10.6 Change of Phase Upon Reflection - Thin films
2.10.7 Dispersion
2.11 Diffraction
2.11.1 Introduction
2.11.2 Single Slit Diffraction
2.11.3 Two Slit Diffraction
2.11.4 The diffraction grating
2.11.5 Diffraction by a Circular Aperture
2.11.6 Limit of Resolution
2.11.7 Fraunhofer Diffraction as a Fourier Transform
2.11.8 Optical Spatial Filtering
2.11.9 The Pinhole Spatial Filter
3. Geometric Moire
3.1 Introduction
3.2 Terminology
3.3 The Moire Phenomenon
3.4 Mathematical Analysis of Moire Fringes
3.5. Relationships Between Line Grating and Moire Fringes
3.6 Moire Patterns Formed by Circular, Radial and Line Gratings
3.7 Measurement of In-Plane Displacements
3.8 Measurement of Out-of-Plane Displacements
3.9 Measurement of Out-of-Plane Slopes
3.10 Sharpening of Moire
Fringes
3.11 Moire of Moire
4. Coherent Moire and Moire Interferometry
4.1 Introduction
4.2 Superposition of Two Diffraction Gratings
4.3 Moire Patterns
4.4 Optical Filtering and Fringe Multiplication.
4.5 Advantages Offered by Coherent Moire
4.6 Moire Interferometry
4.6.1 Introduction
4.6.2 Optical Arrangement
4.6.3 The method
4.6.4 Determination of strains
5. Moire patterns formed by remote gratings
5.1 Introduction
5.2 Geometric Moire Methods
5.2.1 Introduction
5.3 The coherent Grading Sensing (CGS) Method
5.3.1 Introduction
5.3.2 Experimental Arrangement
5.3.3 Governing Equations
6. The method of caustics
6.1 Introduction
6.2 Governing Equations for Reflective Surfaces
6.3 The Ellipsoid Mirror
6.4 Intensity of a Light ray Illuminating a Transparent Specimen
6.5 Stress-Optical Equations
6.6 Crack Problems
6.6.1 Introduction
6.6.2 Principle of the Method
6.6.3 Opening-Mode Loading
6.6.4 Mixed-Mode Loading
6.6.5 Anisotropic Materials
6.6.6 The state of Stress Near the Crack Tip
6.6.7 Comparison of the Method of Caustics with Other Optical Methods
7. Photoelasticity
7.1 Introduction
7.2 Plane Polariscope
7.3 Circular Polariscope
7.4 Isoclinics
7.5 Isochromatics
7.6 Isochromatics with White Light
7.7 Properties of Isoclinics
7.8 Properties of Isochromatics
7.9 Compensation
7.9.1 Introduction
7.9.2 The Tension/Compression Specimen
7.9.3 Babinet and Babinet-Soleil Compensators
7.9.4 Sernarmont Compensation Method
7.9.5 Tardy Compensation Method
7.10 Determination of Photoelastic constant fs
7.11 Stress Separation
7.12 Fringe Multiplication and Sharpening
7.13 Transition from Model to Prototype
7.14 Three-Dimensional Photoelasticity
7.15 Photoelastic Coatings
7.15.1 Introduction
7.15.2 Transfer of Stresses From Body to Coating.
7.15.3 Determination of Stresses
7.15.4 Reinforcing Effect
7.15.5 Photoelastic Strain Gages
8. Interferometry
8.1 Introduction
8.2 Interferometric Systems
8.3 Analysis of Interferometric Systems
8.3.1 Introduction
8.3.2 The Mach-Zehnder Interferometer
8.3.3 The Michelson Interferometer
8.3.4 The Fizeau-Type Interferometer
8.3.5 Other Interferometers
8.3.6 A Generic Analysis of Interferometers
9. Holography
9.1 Introduction
9.2 Holography
9.3 Holographic Interferometry
9.3.1 Introduction
9.3.2 Real-Time Holographic Interferometry
9.3.3 Double-Exposure Holographic Interferometry
9.3.4 Sensitivity Vector
9.4 Holographic Photoelasticity
9.4.1 Introduction
9.4.2 Isochromatic-Isopachic Patterns
10. Optical Fiber Strain Sensors
10.1 Introduction
10.2 Optical Fibers
10.2.1 Introduction
10.2.2 Structure
10.2.3 Principle of operation
10.2.4 Applications
10.2.5 Advantages and disadvantages
10.3 Fiber Optic Sensors (FOS)
10.3.1 Architecture of a FOS
10.3.2 Classification of FOSs
10.3.3 Interferometric Fiber Optic Sensors (FOS)
10.3.4 Fiber Bragg Grating Sensors (FBGS)
10.3.5 Multiplexing
10.3.6 Advantages and disadvantages of OFSs
10.3.7 Applications of Fiber Optic Sensors
11. Speckle Methods
11.1 Introduction
11.2 The Speckle Effect
11.3 Speckle Photography
11.3.1 Introduction
11.3.2 Point-by-Point Interrogation of the Specklegram
11.3.3 Spatial Filtering of the Specklegram
11.4 Speckle Interferometry
11.5 Shearography
11.6 Electronic Speckle Pattern Interferometry (ESPI)
12. Digital Image Correlation (DIC)
12.1 Introduction
12.2 Essential Steps of DIC
12.3 Speckle Patterning
12.4 Image Digitization
12.5 Intensity Interpolation
12.6 Image Correlation - Displacement Measurement
12.7 2-D and 3-D Displacement Measurements
13. Thermoelastic Stress Analysis (TSA)
13.1 Introduction
13.2 Thermoelastic Law
11.3 Infrared Detectors
13.4 Adiabaticity
13.5 Specimen Preparation
13.6 Calibration
13.7 Stress Separation
13.8 Applications
14. Indentation
14.1 Introduction
14.2 Contact Mechanics
14.3 Macro-Indentation Testing
14.3.1 Brinell Test
14.3.2 Meyer Test
14.3.3 Vickers Test
14.3.4 Rockwell Test
14.4 Micro-Indentation testing
14.4.1 Vickers Test
14.4.2 Knoop Test
14.5 Nanoindentation Testing
14.5.1 Introduction
14.5.2 The Elastic Contact Method
14.5.3 Nanoindentation for Measuring Fracture Toughness
15. Nondestructive Testing (NDT)
15.1 Introduction
15.2 Dye Penetrant (DPI)
15.2.1 Principle
15.2.2 Application
15.2.3 Advantages and Disadvantages
15.3 Magnetic Particles Inspection (MPI)
15.3.1 Principle
15.3.2 Advantages and Disadvantages
15.4 Eddy Currents Inspection (ECI)
15.4.1 Principle
15.4.2 Advantages and Disadvantages
15.5 X-ray Diffraction
15.5.1 Introduction
15.5.2 X-rays
15.5.3 X-ray Diffraction
15.5.4 Measurement of Strain
15.5.5 Instrumentation
15.6 Ultrasonic Testing (UT)
15.6.1 Introduction
15.6.2 Operation
15.6.3 Advantages and Disadvantages
15.7 Acoustic Emission Testing (AET)
15.7.1 Introduction
15.7.2 Acoustic Emission Testing
15.7.3 Advantages and Disadvantages
16. Residual Stresses - The Hole Drilling Method
16.1 Introduction
16.2 Hole-Drilling Method
16.3 Uniaxial Residual Stresses
16.4 Biaxial Residual Stresses
16.5 Variation of Residual Stresses Through the Thickness
16.6 Nondestructive Methods for Measuring Residual Stresses
