Balsa Bridge Challenge

The purpose of this challenge is for you to apply structural technology to design the most efficient bridge possible. The bridge will span a 12 inch gap and be loaded in the center until it breaks. The lightest bridge that holds the most weight will be the winner.

Achievement

To meet the requirements of this challenge you must:

1. Sketch a design for a bridge in your engineer's notebook.
2. Model the bridge using MDSolids (or another software program).
3. Make changes to optimize your design.
4. Draw a full scale template for your design. Show the design to your teacher and have it approved.
5. Make your bridge out of balsa wood and glue.
6. Weigh your bridge in ounces.
7. Test your bridge on the load tester. Record the maximum load in pounds in your notebook.
8. Calculate how many times its own weight the bridge held.
9. Document each step in your notebook and communicate your results in the way the teacher specifies.

Constraints

The bridge must meet these specifications:

• At least 12 ½ inches long but not more than 15 inches long.
• No more than 3 inches wide and not more than 7 inches tall.
• Weigh no more than 1.1 ounces.
• Made of 1/8 inch by 1/8 inch balsa wood and the glue provided by the teacher. No other material may be used.
• No part of the bridge can be below the support surfaces.
• The bridge must be design to support the load plate in the center of the span no more than 1 ½ inches above the support surfaces.
• The load plate is 2 inches long and 2 inches wide. It is loaded by a 3/8 inch rod extending below the plate.
• The long side of the load plate is parallel to the long side of your bridge.
• You do not need to have a road surface or approach ramps for your bridge.

The teacher may modify these rules as needed to provide a fair challenge

Last updated 28 January 2013