5ME6.1: EXPERIMENTAL STRESS ANALYSIS (Elective)

 

 

  1. Review of three dimensional Analysis of stress, three dimensional Analysis of strain, Stress/Strain transformation, Stress - Strain relations and theory of failure. Plane stress. Theoritical and Experimental stress analysis is useful in design?

  2. Review of nature of light, polarisation of light, decomposition of elliptically polarised light, crystal optics, Quarter wave plate half wave plate, production of plane polarised light, light ellipse characteristics.

  3. STRAIN MEASUREMENTS: Introduction to Mechanical gauges, Optical gauges, Electrical gauges, Pneumatic gauges, accoustic strain gauges for measurement of strain (atleast one example of each type)

  4. ELECTRICAL RESISTANCE GAUGES: Introduction, Gage sensitivity,Gauge factor, Types of Metal Resistance Gauges Gauges, Gauge Materials, Backing Materials, Adhesives, Protective Coatings, A Typical Method for Bonding Strin gauges, Checking Adequacy of Bonding, Strain Gauge Lead Wire and Connections, Semiconductor Strain Gauges.

  5. PERFORMANCE OF STRAIN GAUGES: Introduction, Temperature Compensation, Strain cycling, Transverse senstivity, Gauge length, strain gauge Response to Dynamic Strain Gauge Excitation levels, Stability, environmental Effects on Performance., Performance of Semicondustor Strain Gauges.

  6. STRAIN GAUGE CIRCUITS: Introduction, Wheatstone Bridge, Circuit senstivity, Constant Current Resisteance Bridge, Error due to Input Impedance of the Measuring Instrument, Principal Features of the Unbalanced Bridge System, Bridge Balancing, Reference Bridge, Potentiometer Circuit, Constant - current Potentiometer Circuits, Temperature Compensation, Effects of lead Wires, Strain Gauge Transducers, Multiple Gauge Circuits, Slip rings, Calibration of strain Measuring Systems

  7. STRAIN GAUGE ROSETTES: Introduction, Three element Rectangular Rosette, Four element Rectancular Rosette and Tee - Delta Rosette. Two Element Rectangular Rosette. Transverse Senstivity Errors in Rosettes. Shear - strain gauges. Stress Gauge

  8. TWO DIMENSIONAL PHOTOELASTICITY: Introduction, Stress optic Relations Two Dimensional Case, Plane Polariscope, Isochromatics and Isoclinics. Analysis through Trignometric Pesolutions, White Light Source and Monochrometic Light Source, Circular Polariscope Dark Field Arrangement. Jones Calculas, Matrix Representation of plane polarized Lights and Plates and 14 plates, PLane polariscope Analysis uaing Jones Calculas, Circular Polariscope Analysis Using Jones Calculas, Circular Polariscope - dark Field Arrangement, Circular. Polariscope - Light Field Arrangements, Isoclinic and Isochromatic Fringe Order at a Point, Methods of a Compensation, Reversibilityof Optical System, Calibration Methods, Use of White Light in Photo-elastic Analysis. Photo-elasticmaterials, Reflection Polariscope.

  9. TWO DIMENSIONAL PHOTO-ELASTIC DATA COLLECTION AND ANALYSIS: Introduction, Photo-elastic Data, Stress Components, Sepration Techniques

  10. THREE DIMENSIONAL PHOTOELASTIC DATA COLLECTION AND ANALYSIS: Introduction, Stress Optic Law, Secondary Principal Stresses, Integrated Retardation Pattern. The Stress Freezing Method. Photoelastic Data from Three Dimensional Model Slice. Maximum Information Obtainable from Photo-elastic Observations. The Shear Difference method. refraction Effects. The Complete Procedure, Material Fringe Constant at Critical Temperature. Axisymmetric Stresses, The torsion Problem.

  11. APPLICATION FOR PHOTOELASTICITY: Introduction, Type of Applications, Properties of an Ideal Photo elastic Material, Casting Techniques, Machining of Photo Elastic Castings, Stress Releiving or Annealing Process, Minimization of Shrinkage Stresses in a Photo elastic Model Material, Scaling Model-Prototype Relations, Two Dimensional Applications, Three Dimensional Applications

  12. MOIRE METHOD AND ANALYSIS: Introduction, Moire Phenomenon, Moire Fringe Analyses,Moire Techniques for Inplane Problems, Analysis Procedures, Moire Techniques for Out of Plane Problems, Special Problems with Moire Technique, Moire Grating Production, Printing and Photography

  13. BRITTLE COATING METHOD: Introduction, Relation Between the State of Stress in Coating and that on the Model, Laws of Failure of Brittle Coatongs Coatings, Crack Patterns and Interpretationsod Crack pattern Data, Isostatics and Isoentatics, Types of Brittle Coating Materials, RelativeMerits of Stress - Coat and All - Temp Coatings, Variable Inluencing Accuracy of Brittle Coating Appliocation, Properties of Stress Coat Materials , Crack Detection Tehniques. Model - Surface Prepaation and Application of Coating, Calibration of Britle - Coating Materials. Brittle Coating Techniqu Applied to a Specific Problem

List of Recommended Books:

  1. Experimental Stress Analysis. Dally, J.W. and W.F. Riley. McGraw Hill, 2nd Ed., New York, 1978

  2. Photo elastic Stress Analysis. Kuske. A and G. Robertson, John Wiley and Sons., London, 1974

  3. Handbook of ESA, Hetenyi; M(ed), John Wiley and Sons, New York. 1950

  4. Moire nalysis of Strain, Durelli. A.J.and V.J.Parks, Prentice Hall, New Jersey, 1970

  5. Experimental Stress Analysis, I.S. Srinath etal., TMH, 1984

  6. Experimental Stress Analysis, Sadhu Singh, Khanna Publishers, 2001