The Civil and Environmental Engineering Department has embarked on a progressive $100,000 campaign to upgrade the “Strength of Materials Lab,” the key component of the CEE 241 Strength of Materials course, required for all CEE students as part of the department’s core curriculum. The course teaches students how to determine stresses and deformations of structural members subjected to axial loads, torsion, and bending of beams, behavior of columns, and transformation of stress and strain. Professor Sergio Breña, the coordinator of the Structural Engineering & Mechanics group in the CEE department, explained that the two main goals in the lab upgrade are to make the testing equipment more accessible for hands-on usage by all students in the course and to modernize the instrumentation.
As Breña said about the first goal, “Although we planned the laboratories in this class to promote direct hands-on experience to our students, the tremendous growth in enrollment that our department has seen has hindered this goal.”
The number of students taking CEE 241 has approximately doubled in the last six years, creating demands on laboratory equipment that did not exist before. Because of this excess demand, the materials strength-testing equipment is currently only demonstrated, not used directly by the students. Breña said that the department would like to correct this situation by creating several stations with duplicate lab equipment that permit each laboratory section to be divided into small groups of students, who can actually conduct their experiments independently with the supervision of the laboratory teaching assistant.
Having the capability for students to acquire hands-on experience with materials strength testing goes hand-in-hand with College of Engineering Dean Tim Anderson’s new emphasis on having all our engineering students taking part in more hands-on engineering activity throughout their four years here. In that context, Dean Anderson has allocated $40,000 in student fees to support the upgrade of the strength lab. That leaves about $60,000 to be raised so the CEE department can meet its goal of generating the $100,000 required for completely updating the lab.
“The second goal of the upgrade is to modernize our labs and expose our students to the state-of-the-art equipment they’re going to be finding in their professional lives,” said Breña. “We recently had our ABET [Accreditation Board for Engineering and Technology, Inc.] evaluation process, and the evaluators pointed out that the equipment we use for our labs is a little bit outdated. They encouraged us to upgrade that equipment.”
As every engineering school in the country knows, when ABET speaks, people listen! “This is the kind of advice that we have to pay attention to in order to keep the ABET evaluators satisfied with our progress,” said Breña.
The strength of materials laboratory, conducted in Gunness 18, is one of three required laboratory experiences that CEE provides its undergraduate students as they work their way through the CEE curriculum. The lab is a fundamental complement to the core Strength of Materials course that leads to advanced classes in the fields of structural and geotechnical engineering.
The course currently holds four different sets of experiments in the Strength of Materials Lab. The first involves determining tensile properties of engineering materials, which illustrates the concept of stress and strain to students and how to measure these quantities in the laboratory. These exercises test the properties of different engineering materials such as steel, aluminum, nylon, cast iron, and others. Tensile properties of these materials are compared, and their importance in structural engineering applications is highlighted.
The next set of experiments concentrates on determining properties of aggregates, which impact the performance of civil engineering materials that use aggregates (such as concrete and pavement). The focus is to measure properties that will be needed for concrete mix design. However, the tests conducted in this laboratory are also used in geotechnical engineering and highway engineering.
Then the third set of exercises covers design of concrete mixtures. Using the measured properties of aggregates determined in the previous laboratory, students design a concrete mix to achieve a target strength. Students learn how important it is to design a concrete mix properly and study the role of trial batches to verify concrete performance.
The fourth lab teaches the fabrication of concrete mix and testing of wet properties of concrete. The concrete mix designed by each group of students is fabricated in the laboratory using the aggregates tested before. Concrete in its fluid state is subjected to several of the tests commonly conducted in the field to ascertain concrete quality (slump, unit weight, air content). Students then fabricate concrete cylinders and beams to be tested at a later date in the laboratory after concrete hardens.
The most expensive piece of equipment needed for all these lab exercises is a tension-compression-testing machine for metal, plastic, and wood, costing approximately $43,000, to complement the one we have. A partial list of additional equipment needed to conduct the four sets of lab exercises would include a $2,700 digi-schmidt, a $3,600 curing box, two $1,400 compressometer/extensometers with digital indicators, a $3,000 specific gravity bench set, a $930 sieve shaker, and a $1,500 drying oven. In addition, there are hundreds of smaller items common to many science and engineering laboratories.
One other key item is a $16,000 data acquisition system. “Instead of the mechanical system we use now,” said Breña,”we would have a laptop computer with custom connections into which we can plug and record readings from instrumentation used in these different labs.”
As Breña summarized the impact of this equipment upgrade, “If our students go to work for a professional internship or actually end up working in a research institution, they will actually be doing the types of labs we teach them how do here. But, beyond that, as an engineer it is always good to be knowledgeable of these laboratories and how they’re performed, and more importantly the information produced from the labs. So all of our students would benefit from the knowledge and education they get out of actually performing these lab tests and using all the equipment themselves.”
If you would like to learn more about the Strength Lab and how to contribute, please call Paula Sakey, Director of Development, at (413) 545-6396. (March 2014)