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Bridge Project Report
By: Maggie Liu Grade 5C Engineering/Design
Bridge Project Report
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Section 1: Objective: The objective is to build the strongest balsa wood bridge while meeting certain specifications. The strength of the bridge will be determined by the weight of the load (in grams) divided by the weight of the bridge (in grams) and that will equal its strength.
Section 2: Background Our teacher gave us an opportunity to build a bridge out of balsa wood. Next we researched different types of bridges. Then we found out that the “TRUSS BRIDGE DESIGN” would work best for this project. Last, we chose a specific truss bridge to build. I chose the Bow Truss Bridge.
Section 3: Question: Which truss design would be the best for building the strongest balsa wood bridge?
Section 4: Hypothesis I think that the Bow Truss Bridge is going to be great for this assignment/project. It doesn’t acquire a lot of wood, and it looks really strong.
Section 5: Description of Experiment ● 1. 2. 3. 4. 5. 6.
Materials Needed: Craft Glue Balsa Wood X-Acto knife Ruler Shoe Box (For holding materials) Graph Paper
● Procedure: 1. 2. 3. 4. 5. 6.
Make a plan for the two sides on the graph paper (blue print) Start cutting the members (balsa wood) for the 2 sides with X-Acto knife. Next, start gluing your members according to your plan. You need to make the 2 sides Start planning the base Then, cut the members (balsa wood)
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7. Glue the base members together and connect it to the 2 sides 8. Optional: You can add reiforcements to the base, top, and sides 9. Specifications: Make sure your bridge is between 25-40 cm., and weigh less than 200 grams, and can stand alone.
â—? Results:
This is my bridge.
Bridge Strengths Bridge Type/Name of Student
Bridge Strength Number
Warren Bridge with Verticals Amy
321.3
Jacinda
199.4
Darrin
143.3
Joseph
222.5
Hina
244.5
Alice
400
Kevin
84.8
Ethan
37.2
Warren Truss Devin
234
Hudson
311.4
Tony
244
Raymond
462.2
Diem-Mi
589
Jesse
198
Ryan
200
Carina
78.9
Sally
486.2
Howe Truss Dora
211.3
Clare
746.1
Claudia
289.5
Lea
390.6
Bow Truss Maggie
372.5
Zoe
261.1
Baltimore Truss Lionel
406.9
Camelback Truss Owen
72.6
Average Strengths Bridge Type
Average Strength
Warren Bridge with Verticals
206.625
Warren Truss Bridge
311.52 (repeating 2)
Howe Truss Bridge
409.375
Bow Truss Bridge
316.8
Baltimore Truss Bridge
406.9
Camelback Truss Brige
72.6
Graph of Results:
Section 6: Conclusion My hypothesis was incorrect, the Howe Bridge is stronger than the Bow Truss. You can see Clare had a bridge strength of 746.1 (Howe Bridge). Also, we did the average strength of each bridge, and Howe Bridge also was strongest. I learned that perhaps the results were not so fair. We didn’t have enough control. People could use more glue, and there was different amount of people each type. People may just build better than others. People were also doing making different bases. Some built roofs, some did not. But I did learn something from looking at the stronger bridges. Their sides were simple, leaving more wood for the base. The base had reinforcements, not too much, but just the right amount. For the base, two layers are food because if one layer break, the second will still stay. The weight barrier could be dropped into the base easily. There were roofs on the stronger bridges. Just a few simple ones. I don’t think the length of the bridge matters, only the width. During this project, I learned a lot. I learned, for example, cut my members longer, or it will be hard to glue. During the process, I felt excitement when I built the bridge; nervous when I thought about the competition; frustration when I couldn’t fit the members together. The most important thing I learned from this project is: don’t give up, be patient with your work. Next time, if there is any, I am going to try the Howe Bridge. I would like to do something different in sixth grade so I can learn more things. Something like: What material is fit to keep things cold?
Section 7: Bibliography Websites: "History of Bridges." History of Bridges - Tunnels and Bridges History. Web. 22 Feb. 2017. Pell, Nicholas, “Six Main Types of Bridges,” Synonym.com, Classroom Section, Leaf Group Ltd, Web. 2001 - 2017.