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 Moiré
3.1 Introduction
3.2 Terminology
3.3 The Moiré Phenomenon
3.4 Mathematical Analysis of Moiré Fringes
3.5. Relationships Between Line Grating and Moiré Fringes
3.6 Moiré 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 Moiré Fringes 3.11 Moiré of Moiré
4. Coherent Moiré and Moiré Interferometry
4.1 Introduction
4.2 Superposition of Two Diffraction Gratings
4.3 Moiré Patterns
4.4 Optical Filtering and Fringe Multiplication.
4.5 Advantages Offered by Coherent Moiré 4.6 Moiré Interferometry
4.6.1 Introduction
4.6.2 Optical Arrangement
4.6.3 The method
4.6.4 Determination of strains
5. Moiré patterns formed by remote gratings
5.1 Introduction
5.2 Geometric Moiré 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
