Bridge Types: Tensile & Compressive Forces
Students explore how tension and compression forces act on three different bridge types. Using sponges, cardboard and string, they create models of beam, arch and suspension bridges and apply forces to understand how they disperse or transfer these loads.
Students model different bridge types such as a cable-stay bridge
Using the countless design possibilities of beam, truss, arch and suspension bridges, civil and structural engineers create the bridges that are essential to the infrastructure of our world. To design bridges of any type, engineers must understand the forces that act on every bridge: compression and tension, and then design bridges to handle these forces without breaking or failing. Teams of engineers decide on the bridge type, design and materials to best distribute the load across an obstacle, and draw detailed design plans, specifying materials, measurements, shapes and angles for construction of the bridge.
After this activity, students should be able to:
- Define three major types of bridges, including a beam or truss bridge, an arch bridge, and a suspension bridge.
- Describe and locate compressive and tensile forces acting on various types of bridges.
- Explain situations for which different types of bridges would be best suited.