Which Bridge Design is the Strongest?
By: James Kurtz
Abstract
In my science fair project I tested out 3-d printed bridges to see which design would work the best. I tested out three different bridges. They were beam, suspension, and truss. I wanted to figure out what design would work best for myself. To do this I would release droplets of tap water onto the bridge until the bridge collapsed. Before I tested I predicted with help of my family member who is an engineer and builds bridges that the suspension design would work the best. For example, many of the most famous bridges like the Golden Gate bridge, the Brooklyn bridge, etc., are suspension bridges.
I set up this experiment by building a wood plank where the bridges would balance on. From there I tested the three bridges until I got an average. I tested each bridge 3 different times. I would carefully fill the water dropper up with the same amount of water so I would make this experiment as accurate as possible, because if I was careless the experiment would not end up in being accurate and legitimate. I also used tap water to test all the bridges. Plus, I used the same wooden slab/plank to test the three different bridges.
When I finished testing I finally got my results. The average of the suspension bridge was 158 droplets of water until it collapsed. The average of the beam bridge was 144 until it collapsed. And finally, the truss bridge collapsed with 139 droplets of water, on average. I realized that the bridges were somewhat close, but the suspension bridge pulled it off by staying upright for the largest amount of water put on.
My observations proved my hypothesis was correct correct because clearly the suspension bridge won. A common mistake that could have happened would be not filling the same amount of water into the dropper each time. Another mistake might be not placing the bridge in the same exact spot on the board. I did my best to avoid errors and make the test as accurate as possible.
Question:
The question I wanted to find out was which bridge design would withstand the most water droplets put on.
Problem:
The problem is that numerous bridges fall because of old age or the maximum capacity is broken. So I decided to find out which bridge would hold the most weight and base more bridges of the design.
Hypothesis:
With the help of my uncle who is an engineer we predicted that the suspension bridge would hold up the most amount of weight.