Course Details
Subject {L-T-P / C} : ME6141 : Experimental Stress Analysis { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Prof. Jonnalagadda Srinivas
Syllabus
1. Introduction to principal stresses, stress-strain relations, equilibrium equations, stress and strain measurements. .
2. Photoelasticity: Light and Optics as Related to Photoelasticity Behavior of Light, Polarized Light, Plane Polarizers,, Wave Plates, Arrangement of Optical Elements in a Polariscopic, Constructional Details of Diffused Light and Lens - Type.Theory of Photoelasticity: The Stress Optic Law in Two Dimensions at Normal Incidence, Effects of a Stressed Model in a Plane Polariscope, Effects of a Plane Model in a Circular Polariscope with Dark and Light Field Arrangements. Analysis Techniques: Isochromatic Fringe Patterns, Isoclinic Fringe Patterns, Compensation Techniques, separation Techniques, Sealing Model to Prototype Stresses.Three Dimensional Photoelasticity: Locking in Model Deformation Slicing the Model and Interpretation of the Resulting Fringe Pattern, Effective Stresses. the Shear Difference Method in Three Dimensions.
3. Moire Method of Strain Analysis, Grid Method of Strain Analysis. Holographic interferometry.
4. Strain Measurement Methods:
Basic Characteristics of a Strain Gauge, Types of Strain Gauge,.Electrical Resistance Strain Gauge: Factors Influencing Strain sensitivity in Metallic Alloys, Gauge Construction Temperature Compensation, Factors-Influencing Gauge Section Gauge Sensitivity and Gauge Factor, Correction for transverse Strain Effects, Semiconductor Strain gauge.Rosette Analysis – three element rectangular Rosette. the Delta Rosettee, the Four Element. The Delta Rosette, The Strain Gauge, Strain Circuits, Potensiometer Circuits, The Wheatstone Bridge.
5.Brittle coating Method: Coating Stresses, Failure theories, Brittle Coating Crack Patterns produced by Direct Loading Brittle-Coating Crack Patterns produced by refrigeration techniques, Brittle coating crack, Pattern produced by releasing the load, Double Crack Pattern, Crack Detection, Load-Time relation and Its influence on the threshold Strain Effects of a Biaxial stress Field.
6. Introduction to Digital image correlation.
Essential Reading:
1. J.W. Dally and W.F. Riley, Experimental Stress Analysis, 2nd Ed. MGH.
Supplementary reading:
1. Mubin Khanna, Experimental Stress Analysis, 2003.
2. Dureli, An Introduction to Experimental Stress and Strain Analysis.
3. Srinath et.al. An Introduction to Experimental Stress Analysis - MGH.
4. J.Srinivas, Stress analysis-An introduction to experimental techniques- Narosa Publishers 2015.
5. Jindal, Experimental stress analysis, Pearson Publishers, 2018.
6. Experimental stress analysis for mFreddi, Olmi, Cristofolini,aterials and structures, 2019
Course Objectives
- This course facilitates the student to implement the theoretical concepts of stress and strain in their measurement procedures.
- To understand the photoelastic technique for principal stress measurement on 2-D and 3-D objects
- To provide geometric and displacement Moire fringe techniques and interferometry concepts
- To know the concepts and uses of strain gauges and mounting approaches. To know the digital image correlation technique.
Course Outcomes
Students can have both mathematical and experimental correlation to fully understand the stress and strain measurements. <br />Able to conduct the necessary experimental work.
Essential Reading
- Freddi, Olmi, Cristofolini,, Experimental stress analysis for materials and structures, Springer , 2015
- J.W. Dally and W.F. Riley,, Experimental Stress Analysis, MGH. , 2014
Supplementary Reading
- Sadhu Singh, Experimental stress analysis, Khanna Publishers , 20111
- Jindal, Experimental stress analysis, Pearson , 2018
Journal and Conferences
- Optics and Lasers in Engineering