Breaking Bridges... All in the name of Science!

Tenth grade students enrolled in Engineering Design apply engineering concepts to design, build, and test model bridges. Students use two specific tools in their design process, one to help with the design process (before building the bridge), and one to test the structural integrity of the bridge (after building the bridge). Before bridge building begins, students use West Point Bridge Designer to "model, test, and optimize a steel highway bridge, based on realistic specifications, constraints, and performance criteria" (source).

(Image source: West Point Bridge Designer website.)

Students then construct their model bridges using balsa wood and glue. After construction is complete, students test the strength of the bridges by applying force using a Pitsco Structure Tester. The software attached to the instrument records the force applied so students can record the data as part of their observations. 

"Breaking" a bridge using the Structure Tester.

Software monitors & records force applied to the bridge. (This bridge peaked at 33 pounds.)

Students work together to test the structural integrity of their model bridge.

Noah, a student participating in the project, describes the process:

"We are testing to see how much force the bridge can take before it breaks. This will help us find a weakness. My team's bridge broke at 22 pounds, so we're going to modify our bridge. We could do this without technology but we would have to run a lot more tests to break it to test all the tension points to test how much force it can take." 

Video of bridge breaking (from STEM Academy Twitter)

Some students turned the activity into a friendly competition, seeing which bridge could withstand the most force before breaking. The sound of cracking of balsa wood never elicited so much excitement!