Design Brief

The goal of this project was to build a bridge that had the highest efficiency in the class. We had to create three separate bridge designs that fit the constraints given to us. We then used a formula to calculate the efficiency of the bridge: Breaking Load/Weight x 100.

Constraints:

	Only balsa wood and glue
	Cannot exceed 300 grams
	Minimum length 20 inches
	Cannot exceed 22 inches
	Must continually extend 1 inch above the roadbed
	The out to out width of the structure shall not exceed 3 inches
	The overall depth of the bridge shall not exceed 6 inches
	The distance between supports must be 18 inches
	The substructure of the bridge must be no longer than 18 inches

Before we could build the bridges, we had to do four things. First we had to do research on the internet about different types of bridges. Second, we had to sketch three different bridge ideas on paper. Next, we began using a program called ModelSmart to design and test different bridge ideas. Once we had three efficient bridges we printed them out and analyzed the pros and cons of them. After selecting the best bridge, we drew it on AutoDesk Inventor. Lastly, we constructed and tested our bridges out of balsa wood and wood glue.