Truss Me! It’s great for learning

“Mechanics II” or “Mechanics of Materials” is one of the foundational undergraduate classes in mechanical engineering at ETH Zurich. This past spring, enrollment in the course topped 800 students, setting a new record for ETH. ETH does not have a lecture hall large enough to fit this many students, so the class was simulcast in overflow rooms adjacent to the main lecture hall, which can accommodate 500 students.

Interactive teaching, immersive learning, flipped classrooms—we know the buzzwords, and we know there are good pedagogical reasons to use modern teaching methods. But how does a lecturer engage with students in classes of such size? How does one spark a passion for solid mechanics in young engineers when hundreds of them crowd into lecture halls?

The most striking difference seen in classrooms today compared with a decade ago is the ubiquitous presence of electronic devices. Smart phones, tablets, and laptops are used by most students. They can be much more than a distraction that competes with the lecturer for the students’ attention. They can be a teaching asset. Their use as communication devices in classrooms is well established: students can answer questions posed by the lecturer through online interfaces, and they can raise questions through twitter channels for the class. But beyond that, they can be used for interactive and game-based learning. They can provide hands-on experiences for students, which disrupt classroom routines creatively and effectively and improve learning experiences and outcomes.

One app that is providing such an opportunity for mechanics classes is Truss Me!, an educational game designed by Prof. Julian Rimoli at Georgia Tech. Truss Me! is a game that challenges players to design and build truss structures, using realistic physically based simulations to test their viability and weight. The game incorporates the standard statics concepts taught in introductory mechanics classes (for example, how to equilibrate structures and nodes) and combines them with the mechanics of materials (for example, how columns buckle in compression or bars fail plastically under tension). Structures are assembled by moving trusses with fingers on a tablet, and when a structure fails, it does so visually: buckling or bursting, and crashing to the ground. It makes for intuitive and fun explorations of what does and doesn’t work in truss designs.

During the first lecture of “Mechanics of Materials,” I challenged my 800 students to play the game and win a prize at the end of the term. (Playing did not count for credit or bonus points for the final exam.) The rules were simple: play all the original 15 challenges incorporated in Truss Me! and submit your best scores. The 8 highest-scoring students would be invited to play on the last day of class in front of the entire class, in a live competition.

The final round of the competition took place on May 28th, with Julian Rimoli opening the class session with a talk on the value of games in education, on how he developed and programmed Truss Me! (waiting in a doctor’s office), and how he became an engineering professor after having grown up in the Argentinian pampas. In front of a packed lecture hall (no one had to attend this class—the only purpose was the final round of the Truss Me! game), the 8 finalists first played a semifinal round, which reduced the finalists to 4, and then a final challenge, to determine the winners (see the picture).  Julian programmed three extra challenges for the students to play (now they are available for everyone to play, as challenge 16-18 in the currently downloadable version of the game). 

Seeing students immersed and focused on designing the best truss structure given the constraints, seeing them exploring and testing design ideas with their fingers, live in front of their peers, affirmed the value of the app in engaging students in new ways. Throughout the course, the app was a valuable complement to classroom teaching. Our impression was that we only scratched the surface of what kind of learning environments may become possible in the future. Truss Me! worked for us. The potential of Truss Me! and similar apps for other aspects of mechanics teaching seems enormous.   

Chiara Daraio

Professor of Mechanics and Materials
CLA J 19.2
Tannenstrasse 3
8092 Zurich, Switzerland
daraio@ethz.ch
www.mechmat.ethz.ch