Strain measurements and stress analysis

Abstract

1. Stress, Strain, and Stress-Strain Relationships. Introduction. Stress. Two-Dimensional Stress State at a Point. Principal Stresses. Mohr's Stress Circle. Differential Equations of Equilibrium. Strain and Displacement. Principal Strains and Mohr's Strain Cycle. Stress-Strain Relations. Problems. References. 2. Metal-Foil Resistance Strain Gages. Introduction. Principle of Operation. Gage Configurations and Fabrication. Strain Gage Bonding Agents and Procedures. Gage Factor and Transverse Sensitivity Correction. Environmental Effects on Metal-Foil Strain Gages. Problems. References. 3. Strain Gage Circuitry, Transducers, and Data Analysis. Introduction. Wheatstone Bridge. Correction for Long Lead Wires. Strain-Gage Transducers. Strain-Gage Rosette Data Analysis and Correction. Correction for the Wheatstone Bridge Nonlinearity. Gage Factor for Finite Deformation. Shunt Resistance Calibration. Potentiometer Circuit. Problems. References. 4. Photoelasticity. Introduction. Review of the Nature of Light and Wave Representation. Polarization of Light. Wave Plate and the Principle of Photoelasticity. Analysis of a Stressed Plate in a Plane Polariscope. Analysis of a Stressed Plate in a Circular Polariscope. Tardy Method. Calibration Methods. Determination of Whole-Field Isoclinic Fringe Patterns. The Separation of Principal Stresses. Relationship between Stresses in Models and Actual Structures. Materials for Photoelastic Models. Advanced Photoelasticity. Problems. References. 5. Photoelasticity-Coating Method. Introduction. Reflection Polariscope. Basic Principles of the Photoelastic-Coating Applications. Stress- or Strain-Optic Law for Coatings. Calibration of Photoelastic Coating. Principal Strain Separation Methods. Coating Sensitivity and Selections. Coating Applications. Problems. References. 6. Geometric Moire Techniques in Strain Analysis Introduction. Fundamental Property of Moire Fringes. Geometrical Method of Moire Fringe Analysis in Two Dimensions. Displacement Method of Moire Fringe Analysis in Two Dimensions. Instrumentation. Out-of-Plane Displacement Measurements. Out-of-Plane Slope Measurements. Grating and Their Applications. Problems. References. 7. Holographic Interferometry. Introduction. Interference and Diffraction. Wavefront Recording and Reconstruction by Holography. Displacement Measurement by Holographic Interferometry. Vibration Analysis by Time-Average Holography. Basic Equipment and Technique for Making a Hologram. Comparative Holographic Interferometry. Problems. References. 8. Computer Data Acquisition and Control System. Introduction. Basics of a Computer Data Acquisition and Control System. Components of a Computer Data Acquisition and Control System. Analog Signal Input and Output Channels. Interface for a Computer Data Acquisition and Control System. Summary Remarks. Problems. References. Index.