Building Our Bridge to Fun!
Students identify different bridge designs and construction materials used in modern day engineering. They work in construction teams to create paper bridges and spaghetti bridges based on existing bridge designs. Students progressively realize the importance of the structural elements in each bridge. They also measure vertical displacements under the center of the spaghetti bridge span when a load is applied. Vertical deflection is measured using a LEGO® MINDSTORMS® EV3 intelligent brick and ultrasonic sensor. As they work, students experience tension and compression forces acting on structural elements of the two bridge prototypes. In conclusion, students discuss the material properties of paper and spaghetti and compare bridge designs with performance outcomes.
Students work as civil engineers to create and test bridges for performance to learn about design, forces and material properties.Copyright 2012 Eduardo Suescun, Polytechnic Institute of NYU (left); Harvey Henkelmann, Wikimedia Commons http://commons.wikimedia.org/wiki/File:LittleManateeRiver.jpg (right)
Civil engineers design and construct bridges to meet transportation needs related to traffic, commuting time and over-passing. A range of bridge designs exist, and the choice of which type of bridge to construct depends on space, bridge span, availability and cost of materials, and the budget. Each bridge type has its own structural design depending on service loads, expected traffic, weather, geographical position and seismic activity. Civil engineers take into account the stresses and deformations in all the structural elements of the bridge during the design process. Material selection is another aspect of the design process. The most common materials utilized in bridge construction include steel, concrete, wood and bricks. In this activity, students work as civil engineers to design, construct and test their bridge prototypes. Two different construction materials are used and compared. Students also use mechatronic tools, specifically an ultrasonic sensor, to measure vertical displacement under the center of a bridge span when loaded, mimicking the instrumentation and testing performed in real-world civil engineering projects.
After this activity, students should be able to:
- Explain the need for bridges in our communities.
- Identify materials used for bridges construction and explain the properties of these materials.
- Identify the structural elements of bridges.
- Identify the forces acting on bridges.
- Build model bridges and explain the difference between rigid and non-rigid materials used in bridge construction.