Bridge Breaking

In this unit we talked about forces, load, and triangles. The purpose of this project is to make a bridge only using 50 popsicles sticks and white glue. The requirements are that the bridge will have to have a length of at least 1 foot and support a weight of at least 5 pounds. I learned about triangles and how they are the best for most structures because they distribute weight equally. I also learned a lot about the different types of bridges and when a certain type of bridge is used.

At first my partner and I were thinking about making an arch bridge, but it turned out that we didn't have enough time to make the material bend. So we decided that we would look up more basic designs and found that the truss bridge is used for short distances because of its stability. A few sketches later we had found our design that is based on the Bridge L-158 design.

Our sketch to model ratio 1cm. : 1inch.

Our bridge is 18 inches long and about 3.5 inches tall. For angles we mostly used 90 degrees, but for the truss itself we used 60 degree angles. Out of the 50 Popsicle sticks that we were given we used all of them. 

At first we were going to design an arch bridge, but then we had to think of easier bridges that didn't require that much time and material, yet were just as strong as an arch bridge. So that's when we decided to do a truss bridge. At first we had a general design that we were going to stick to, but we had to pay attention to the most vital parts of the bridge. For example the base of it had to be pretty sturdy to keep the truss system in place. For the base we started with two layers of sticks, but it could still snap too easily, so we added one more layer to re-enforce it. Also when it came to building the truss system I had to make little notches at the base so that they would stay in place while the glue dried.

My main issue was the fact they all we had to work with was Elmer’s white glue, which takes a really long time to dry. So what happened was that I just needed to plan wisely and hope for the best that it wouldn't fall apart overnight. Another issue was that when we made measurements for the bridge and had plans, some of the parts of the bridge didn't match up like we planned so we had to improvise. What I learned from both of these issues is that you always have to expect the unexpected.

Citations

"Bridge L-158." Wikipedia. Wikimedia Foundation, 19 Jan. 2015. Web. 21 Apr. 2015.

"Parts of a Roof Truss." Roof Truss. QuinStreet, 2015. Web. 21 Apr. 2015.