Pasta Bridge Project

Authors: Gregory Mcmichael, Matthew Morris, Chris Nelson, Kyle Perry, William Pfeffer, John Yorina

Abstract. The objectives of this project are to build a bridge constructed of pasta, maximize the load ratio, and conform to the presented specifications. For our design we decided on a classic Howe Truss bridge, because it was simple, strong and relatively light.  The resulting bridge that was constructed ended up being much lighter than expected, and therefore we do not predict that it will be able to support as much weight as it could have if we would have added more support and structure to it. However, for its light weight, we do believe that it will be able to support a lot of force relative to the bridge’s weight.

Introduction

A bridge is defined as a structure that spans or provides a route across a gap or barrier (Dictionary.com). Many bridges have to be able to support a large amount of weight, and so most are built out of steel and concrete. This is due to the fact that a bridge can be designed to maximize the load that it can withstand, but the materials used have a large impact on what the bridge can actually hold. A bridge can only be as strong as the weakest material that it is made of, assuming that it is designed correctly. Depending on the design of a bridge, it can have weak points. The joints of a bridge should transfer the forces equally throughout the bridge if it is built correctly. This is the same for the bridge supports, they should all work together to share the load on the bridge, therefore it allows the bridge to stand up against more force. It is also important to identify what type of bridge is needed. There are many types of bridges, and most have different uses depending on the situation at hand (Cridlebaugh).

Objectives

The objectives of this project were to build a bridge out of pasta and maximize the bridge’s load ratio, while still conforming to the set specifications.

Procedure

We considered many different options when trying to come up with a good bridge design that would be strong and also that would follow the required specifications. The finial design was used because it is a classic design that is used often on real bridges, a bridge deck supported on the bottom by I beams and trusses for each side of the bridge for increased support and strength. The most difficult limitation to work with was the issue of weight, because we could not put as many supports on the bridge as we would have liked to because the bridge would be too heavy. 

Results and Discussion

The specifications of the project limited many of the designs that were considered, because of height, and weight. Trying to find a design that was as light weight as possible, but as strong as possible was difficult. Once the design was determined, fabrication of the bridge consisted of first starting the side trusses. The bases of the trusses were two pieces of fettuccine glued together, and then uprights were glued onto the base section. A top was attached next, followed by cross sections for increased structural support. The two side pieces were attached to the roadbed, 2 pieces of lasagna glued together. Supports were added across the top, and I beams were added across the bottom under the roadbed for increased structural integrity.

Conclusion

The resulting bridge that was constructed ended up being much lighter than expected, and therefore we do not predict that it will be able to support as much weight as it could have if we would have added more support and structure to it. However, for its light weight, we do believe that it will be able to support a lot of force relative to the bridge’s weight.

References

"Dictionary.com/bridge." Dictionary.com. 2005. Lexico Publishing Group, LLC. 24 Oct. 2005 <http://dictionary.reference.com/search?q=bridge>.

Cridlebaugh, Bruce S. "Bridge Basics-A Spotter's guide to bridge design." Bridges and Tunnels of Allegheny, PA. 2002. 26 Oct. 2005 <http://pghbridges.com/basics.htm>.

 

Appendix

 

Piece name Material used Quantity Weight
     
Vertical supports Fettuccine 10 19 g
Horizontal supports Fettuccine 14 26.6 g
Diagonal supports Fettuccine 24 45.6 g
Roadbed Lasagne 1.5 28.5 g
I-beams Fettuccine 8 15.2 g