Hands-on experimentation a key aspect of TAM 456 course


Maddie Yang

TAM 456 (Experimental Stress Analysis) has been taught at the University of Illinois for over 50 years. Throughout its extensive history, the class has continually evolved to teach both traditional and modern experimental methods.

Students holding large beam.
Photo by Professor Emeritus Jim Phillips.

“There are several other courses offered at the senior and graduate levels about solid mechanics, theoretical calculations about stresses and bodies, but until you go into the laboratory and attempt to measure these various quantities yourself, you do not appreciate the challenges involved in obtaining reliable data,” said Professor Emeritus Jim Phillips, who has been heavily involved in the course’s growth and development over the last few decades.

Unlike many other upper-level TAM courses, TAM 456 has a heavy focus on hands-on experimentation, teaching students common and useful methods for measuring stress in materials that are presently being used in industry.

“When I arrived in 1969, [TAM 456] was already being taught,” said Phillips, who began teaching the class in 1976 and continues to run the laboratory component to this day. “[Historically,] the course has had certain content in the way of traditional experimental methods and some of these are still being taught. Others have been phased out and replaced with newer content… I think the current content, which includes these traditional methods as well as newer methods, is very important for students interested in structural analysis, material investigation, and any kind of mechanical testing applications.”

The class covers a wide range of mechanical testing methods including the use of electrical resistance strain gauges, photoelasticity, particle tracking, and digital image correlation, all of which are used in industry and research laboratories today. The use of electrical resistance strain gauges is one of the oldest and most reliable mechanical testing methods; in contrast, digital image correlation, which was refined and improved by former UIUC PhD student Michael Sutton, has become important in recent years due to its full-field aspect and attributes for investigating bodies that deformed under load. 

“One of the most valuable things about the course is being able to go through the entire process of gathering data scaffolded by people who already know where the pitfalls are and can point them out so that you can [learn to] avoid them,” said assistant professor and current course instructor Shelby Hutchens, who added digital image correlation to the repertoire of methods covered in the course.

Interested students can register to take TAM 456 during the Spring 2023 semester. The course is open to graduate students and undergraduate students who have taken TAM 251.