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ME825
Strain and Motion Measurement
"Without measurement there can be no science and therefore no engineering."
3 semester credits
Spring semester 2004
Scheduled meeting times:
MWF 11:30-12:20;but the time can be changed to accommodate
the needs of participants; Room 1314 EB
Approx. 10 laboratory experiments at average of 2 hours each; by arrangement.
Note on enrollment process:
Because the course is open to students from other fields, such as physics, enrollment might involve an extra step. The computerized enrollment system might not allow you to enroll directly. In this case, obtain an "over-ride" form from the secretary in the Mechanical Engineering Department. This is a nuisance, but it is routine and takes only a few minutes. In the meantime, we are trying to fix the problem.
Instructor:
Prof. Gary Cloud
Materials Science and Mechanics Dept.
College of Engineering
Michigan State University
East Lansing, MI 48824 USA
email Prof. Cloud
phone: 517-355-9574
Textbook:
Experimental Stress Analysis 3rd Edition
J.W. Dally and W.F. Riley
College House Enterprises, LLC, 1991
5713 Clen Cove Drive, Knoxville, TN 37919-8611
http://www.collegehousebooks.com
Grading:
Grading basis:
- midsemester exam 33%
- final exam 33%
- laboratory 34%
- optional project 10%
- total percent 110%
Purpose:
Perform quantitive observations of the responses of an object or objects (structure) to a system of forces (loads).
Ancillary purpose:
Learn how to utilize sensors and measurement technologies to obtain valid data that are useful in science and engineering.
- In all cases, the physical phenomena that undergird the measurement processes are emphasized.
- "structures" is here used as a very broad term. It includes typical engineering components (machines, buildings), biomechanics systems (musculo-skeletal, plants, agricultural products), geomechanical entities (glaciers, rocks), and so on.
- "forces" includes various stimuli including mechanical loads, gravity, thermal excitation, etc.
- "responses" are of various types, including deformation , strain, motion. They may be steady-state (static) or transient (dynamic) in nature.
- In some case, we are interested in direct measurement of strain or deformation. In other cases, we use measurement of strain as an indirect way to quantify some other parameter, such as load, by using the strain measuring technology in a transducer.
- We concentrate on making measurements in the "real world;" but, sometimes one must use a simulated environment and/or models.
Motivations:
Experimental mechanics is of fundamental importance in engineering, since it deals with the actual responses of objects in the real world. It is important in support of design and manufacturing, first in determining service loads and secondly in establishing the performance of components and structures. With increasing involvment of complex materials, including biomaterials and semiconductors, and interest in ever-smaller sensors and actuators, including MEMS devices, obtaining valid experimental data is critical. Nondestructive evaluation, another component of experimental mechanics, is increasingly required to measure the integrity of structures before and after service.
Audience:
This course should be of interest to persons who are interested in
experimental mechanics, sensors, physics, stress analysis,
motion measurement, engineering design, structural testing,
metrology, nondestructive inspection , and
similar fields.
Coverage and approach:
The syllabus will follow the textbook quite
closely. Supplemental reading material on motion measurement and optical methods will be provided.
Topics and approximate hours are:
topic hours
basic measurements, experimental mechanics 4
resistance strain gages 10
transducers and sensors 5
motion measurement 10
photoelasticity 5
moire introduction 2
holography introduction 2
speckle methods introduction 3
Laboratory experiments:
Laboratory experience with all the methods is included in the
course. Laboratory experiments and demonstrations are listed below. The approach is
specifically designed to accommodate students of various
backgrounds, including but not limited to physics and
engineering.
Note: Typically, the class meets periodically in the lab for
demonstrations related to the experiments. The experiment stations
are left set up, so that students can perform the experiments
singly or in pairs at any time.
Some flexibility in choice of experiments is provided to
accommodate students from areas other than solid mechanics.
- Application and testing of resistance strain gage or rosette
- Elastic wave propagation
- Low-frequency strain measurement
- Simple transducer
- Strain rosette analysis
- Accelerometer calibration
- Dynamic response of structure
- Basic modal analysis
- Photoelasticity
- Electronic speckle interferometry
- Moire demonstration
- Holographic interferometry demonstration
- Speckle photography demonstration
- Laboratory project (may be an option)
Prof. Cloud assists Derek Polzien, Mike Gerard, and Rod Prior in modal analysis of the 1997 Formula SAE race car frame.
