Bridge construction challenge with k'Nex
A variety of challenges, investigations, and problems can be created related to bridges. This one used K'Nex as building materials.
Source for these and more bridge terms.
- Learners are shown photos of bridges.
- Ask. Can you build a sturdy bridge with K'Nex?
- Build bridges
- Share constructed bridge designs
- Introduce the three kinds of forces that affect the stability of bridges.
- Tension - pull or stretch
- Compression - push together
- Torsion - twist
- Tell. A simple way to test a bridge for compresion, tension, or torsion forces is to tie a piece of thread or string between two connectors that are connected with a girder and remove the girder. You can tell if the thread gets tighter, looser, or twists what kind of forces there are at different places on your bridge.
- Test bridges
- Share results.
Pictures of bridge tests
Test with thread added and rod removed
Test with thread added and two piers removed
Test with thread added and grey rod removed
Test with thread added and white rod removed
Statements made when testing bridges:
- When the weight shifted, one side displayed tension while the opposite side showed compression.
- Once we removed 2 girders, there was some slight compression at the point of removal.
- When we removed two girders, force was applied which caused compression.
- When we removed a smaller girder and a larger girder, force was applied which caused tension.
Piers & beam
Piers, beam, & rails
Trusses, pier, & deck
Bridge photo album