151-0535-00L Optical Methods in Experimental Mechanics
| Semester | Autumn Semester 2019 |
| Lecturers | E. Hack, R. Brönnimann |
| Periodicity | yearly recurring course |
| Language of instruction | English |
Courses
| Number | Title | Hours | Lecturers | ||||
|---|---|---|---|---|---|---|---|
| 151-0535-00 G | Optical Methods in Experimental Mechanics | 3 hrs |
| E. Hack, R. Brönnimann |
Catalogue data
| Abstract | The lecture introduces optical methods to assess the mechanical behaviour of a structure, to determine material parameters, and to validate results from numerical simulations. Focus is on camera-based techniques for deformation, strain and stress analysis. Applications, strengths and limitations are discussed. The lecture includes two afternoons of hands-on experience at Empa in Dübendorf. |
| Objective | The students are enabled to design basic optical set-ups and to describe the process of image formation. They understand the working principle of various optical techniques for shape, deformation and strain measurement. Most notably, they can explain how the measurand is transformed into an interference signal, a change of polarization state or of surface temperature. They know the main application fields of the individual techniques. They are able to choose the most appropriate technique for solving a measurement task and to estimate its expected resolution. Through the hands-on experience the students gain a deeper and sustained understanding of the content by applying the theoretical foundations to tangible measurement tasks. |
| Content | After an introduction into optics and image acquisition the lecture explains how to transform mechanical quantities such as strain, stress or deformation into an image content. The measurement techniques make use of a variety of optical principles: - Triangulation (Digital Image Correlation, Fringe Projection) - Interference (Speckle Pattern Interferometry, Shearography) - Diffraction (Moiré-Interferometry, Fiber Bragg Gratings) - Birefringence (Photoelasticity) - Infrared radiation (Thermal Stress Analysis) In addition, time-resolved measurements in the context of modal analysis and transient events are explained. The calibration of imaging optical instruments and their application to the validation of numerical simulations are discussed. The content includes: - Introduction to optics and imaging - Digital Image Correlation - Structured light techniques - Diffraction and interferometry - Speckle pattern interferometry - Modal analysis and transient deformations - Applications to microsystems and interfaces - Stress analysis: Photoelasticity - Stress analysis: Thermoelasticity - Calibration and validation of numerical models - Fibre based methods The lecture includes two afternoons at Empa, where the student will gain first-hand experience with optical methods. These hands-on laboratory classes may include e.g. Digital Image Correlation, Speckle pattern interferometry, Thermal Stress Analysis, Fibre optic sensors, Fringe projection, depending on availability of the equipment and the interest of the students. |
| Lecture notes | Copies of the presented slides will be made available on-line through ILIAS. Each lecture contains a set of exercises. You will be invited to a private blog which shall stimulate the discussion of the lecture content and the exercises. Standard solutions for the exercises will be posted with a time shift. |
| Literature | A good overview on the optical methods is presented in the following text books: Toru Yoshizawa, Ed., Handbook of Optical Metrology, 2nd edition, 2015, CRC Press, Boca Raton ISBN 978-1-4665-7359-8 Pramod Rastogi, Erwin Hack, Eds., Optical Methods for Solid Mechanics: A Full-Field Approach 2012, Wiley-VCH, Berlin ISBN 978-3-527-41111-5 W. N. Sharpe Jr., Ed., Handbook of Experimental Solid Mechanics 2009, Springer, New York ISBN 978-0-387-26883-5 |
| Prerequisites / Notice | Basic knowledge of optics and interferometry as taught in basic physics courses are advantageous. |
Performance assessment
| Performance assessment information (valid until the course unit is held again) | |
Performance assessment as a semester course | |
| ECTS credits | 4 credits |
| Examiners | E. Hack, R. Brönnimann |
| Type | session examination |
| Language of examination | English |
| Repetition | The performance assessment is offered every session. Repetition possible without re-enrolling for the course unit. |
| Mode of examination | oral 30 minutes |
| Additional information on mode of examination | If requested by the candidate, examination can be held in German. |
| This information can be updated until the beginning of the semester; information on the examination timetable is binding. | |
Learning materials
| No public learning materials available. | |
| Only public learning materials are listed. |
Groups
| No information on groups available. |
Restrictions
| There are no additional restrictions for the registration. |
Offered in
| Programme | Section | Type | |
|---|---|---|---|
| Mechanical Engineering Master | Mechanics, Materials, Structures | W |  |