Course Details
Subject {L-T-P / C} : ME6141 : Experimental Stress Analysis { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Jonnalagadda Srinivas
Syllabus
| Module 1 : |
Introduction to principal stresses, stress-strain relations, equilibrium equations, stress and strain measurements. .(5 hrs) |
| Module 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. (10 hrs) |
| Module 3 : |
Moire fringe Method of Strain Analysis, Grid Method of Strain Analysis. Holographic interferometry (5 hours) |
| Module 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 Rosette, the Four Element. The Delta Rosette, The Strain Gauge, Strain Circuits, Potentiometer Circuits, The Wheatstone Bridge.(8 hrs) |
| Module 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. Introduction to Digital image correlation. (7 hrs) |
Course Objective
| 1 . |
This course facilitates the student to implement the theoretical concepts of stress and strain in their measurement procedures. |
| 2 . |
To understand the photoelastic technique for principal stress measurement on 2-D and 3-D objects |
| 3 . |
To provide geometric and displacement Moire fringe techniques and interferometry concepts |
| 4 . |
To know the concepts and uses of strain gauges and mounting approaches. To know the digital image correlation technique. |
Course Outcome
| 1 . |
To understand the analytical relations of stress and strain tensors |
| 2 . |
To acquaint the concepts of whole field techniques like photoelasticity, Moire fringe method and brittle coating techniques |
| 3 . |
To get knowledge of strain gauges and practical abilities in experiments. |
| 4 . |
To gain modern concepts of digital image correlation for strain analysis |
| 5 . |
To know the principles of sensor calibration and alternative practical methods |
Essential Reading
| 1 . |
Freddi, Olmi, Cristofolini,, Experimental stress analysis for materials and structures, Springer , 2020 |
| 2 . |
J.W. Dally and W.F. Riley,, Experimental Stress Analysis, MGH. , 2021 |
Supplementary Reading
| 1 . |
Sadhu Singh, Experimental stress analysis, Khanna Publishers , 2022 |
| 2 . |
Jindal, Experimental stress analysis, Pearson , 2020 |
Journal and Conferences
| 1 . |
Optics and Lasers in Engineering |