Interference-optical Methods of Solid Mechanics (eBook)

Abstract 5
From the Author 6
Contents 9
1 Photoelastic Techniques 12
1.1 Basic Physics of Photoelastic Techniques 12
1.1.1 Light Polarization 13
1.1.2 Theory of Piezo-Optical Effect 14
1.2 Transmission of Polarized Light Through the Loaded Object of Optically Sensitive Material Under Conditions of Linearly and 3-D Stressed State 16
1.2.1 Plane Polariscope 17
1.2.2 Circular Polariscope 19
1.2.3 Passage of Polarized Light Through 3-D Stressed Medium 22
1.2.4 Integral Photoelasticity 25
1.3 Research Techniques in Stressed State of Construction Components 26
1.3.1 Research in Plane Problems of Elasticity Theory 26
1.3.2 Research in 3-D Problems by ''Freezing'' Method 30
1.3.3 Photoelastic Coating Technique 33
1.3.4 Scattered Light Technique 36
1.4 Examples of Practical Application of Photoelastic Techniques 39
1.4.1 Analysis of Rectangular Plate Plane Bending 39
1.4.2 Research in Stresses at Sharp Edges of Holes by Integral Photoelasticity Technique 40
1.4.3 Research in Thermoelastic Stresses at Joint Zone Between Inclined Branch Pipe and Shell Cover 43
2 Coherent Optical Techniques 47
2.1 Holographic Interferometry 47
2.1.1 Theoretic Framework of Interference Pattern Formation 48
2.1.1.1 Holography by Double-Exposure Holographic Interferometry 48
2.1.1.2 Image Reconstruction from Hologram 50
2.1.1.3 Change in Phase with Body Straining 51
2.1.2 Measurement of Mechanical Vibrations 54
2.1.3 Certain Peculiarities of Holographic Interferometry Technique 60
2.2 Speckle Photography 60
2.2.1 Laser Speckle Pattern 61
2.2.2 Evaluation of Speckle Width 63
2.2.3 Measurement of Tangential Displacements of Quasi-Planar Objects by Speckle Photography Technique 65
2.3 Electronic Speckle Pattern Interferometry 66
2.3.1 Formation of Correlation Fringes 67
2.3.2 Measurement Designs for Separate Components of the Displacement Vector 70
2.3.3 Electronic Digital Speckle Pattern Interferometry 72
2.3.4 Displacement Measurements by Digital Correlation Speckle Photography and Digital Holographic Interferometry Method 72
2.4 Examples of Practical Application for Coherent Optical Methods 77
2.4.1 Analysis of Object Surface Displacement During Static Deforming 77
2.4.2 Research in Overhead-Track Hoist Displacement by Speckle Photography Technique 79
2.4.3 Research in Characteristics of Material Deforming by EDSPI Method 81
2.4.4 Research in Vibration Characteristics for Construction Components Interacting with Liquid Media 84
2.4.5 Nondestructive Testing of Materials 88
3 Application of Interference Optical Techniques for Fracture Mechanics Problems 93
3.1 Peculiarities of StressStrain State Near Irregular Boundary 94
3.1.1 Stress--Strain State Near Angular Cutout 94
3.1.2 Stress--Strain State Near Crack Tip 96
3.2 Fracture Criteria 99
3.2.1 Force Fracture Criteria 99
3.2.2 Energy Fracture Criteria 102
3.2.3 Deformation Fracture Criteria 105
3.3 Interference Optical Techniques for Determination of Stress Intensity Factors 106
3.3.1 Photoelastic Techniques 106
3.3.2 Coherent Optical Techniques 115
3.4 Shadow Optical Method of Caustics (Caustics Method) 116
3.4.1 Basic Equation of Caustics Method 117
3.4.2 Determination of KI, KII, KIII Under Static Loading 119
3.4.3 Determination of KI Under Dynamic Propagation of Crack 122
3.5 Examples of Practical Problem Solution 125
3.5.1 Crack Propagation Through Boundary of Join Between Dissimilar Materials 125
3.5.2 Crack Propagation from Root of Welded Joint Between Sidewall and Vessel Cover of Power Installation 127
3.5.3 Determination of KIII by Scattered Light Technique 129
3.5.4 Determination of KI in Stationary Crack Under Action of Impact Load 131
4 Experimental Methods for Research in Residual Stresses 134
4.1 General Remarks 134
4.1.1 Types of Residual Stresses 134
4.1.2 Boundary Problem of Residual Stress Determination 135
4.1.3 Methods for Research in Residual Stresses 137
4.2 Destructive Techniques for Research in Residual Stresses 138
4.2.1 Techniques of Component Layer-by-Layer Recutting 139
4.2.2 Technique of Hole Drilling 143
4.2.3 Research in Residual Stresses as an Inverse Problem of Experimental Mechanics 148
4.3 Examples of Research in Residual Stresses in Construction Components 156
4.3.1 Analysis of Residual Stresses at Zone of Pipeline Welded Joint by EDSI Technique 156
4.3.2 Estimation of Residual Stresses in Combustion Engine Cylinder Barrel 157
4.3.3 Analysis of Residual Stresses in Bimetal Sidewall of Reactor Vessel 161
Appendix 1 Moiré Method 165
Appendix 2 X-Ray Technique of Stress Analysis 171
A2.1 Nature and Properties of X-Rays 171
A2.2 X-Ray Interference.Wulff–Bragg Equation 172
A2.3 Basic Relations 173
A2.4 Errors of Method 177
A2.5 Examples of Practical Application 179
References 182