Straw Bridge Design

This is the outline that we will use to make our essay. This outline was copied WORD FOR WORD from the rubric posted on thebmi.org. http://www.thebmi.org/wp-content/uploads/2017/09/2018-Straw-Bridge-Design-Guide-FINAL.pdf click on this link and scroll down to page 8 to see the rubric on the website.

Paragraph 1 (introduction): What is the paper about and why is this bridge being built. What are the basic rules, objectives and restrictions

Paragraph 2: (Literature Review and Academic Research): What are some common bridge types and designs and how do they apply to the Straw Bridge Challenge. How do elements of the science of bridge building relate to the straw bridge challenge?

Paragraph 3:(Experimental Research): Did you form any ideas of

A beam bridge is a very basic type of bridge. It is one large beam that is held by two abutments, one at each end. These two abutments take all of the pressure and weight that is being put on the bridge. Beam bridges need to be stiff and straight for them to work. If the bridge is not stiff enough, the whole bridge will bend and eventually break. Another main type of bridge is a truss bridge. A truss bridge is very similar to a beam bridge. It is a beam that is held by two abutments, one at each end. A truss bridge also has a truss, a structure of connected elements, on top of it. The truss’s elements are mostly triangles. This is supposed to spread out the weight. Rather than having a narrow space where all of the weight is, it makes a wider area where all of the weight can be spread out. This puts less stress on the beam. The next major type of bridge is a suspension bridge. A suspension bridge is a bridge where the deck of the bridge is hung up and supported by suspension cables. These cables take all of the weight that is being put on the roadway. The last main type of bridges is an arch bridge. An arch bridge a beam that has an arch shape underneath it. This arch shape is to reinforce the beam. Rather than taking having all of the weight push on the bridge straight down, the arch spreads out all of the weight. The weight eventually falls on the abutments, keeping most of the weight off of the beam.

One idea was to make a truss bridge. We also had the idea to make an arch bridge. For the truss bridge. The part that is on top of the roadway had a triangle pattern. The roadway also had a triangle pattern on it. For the arch bridge, we used a triangle pattern in between the two straws that made the arch. This is to reinforce the arch since it is taking all the weight. The roadway of the arch bridge has a straight line in the center. An arch bridge was a good option because instead of the weight pushing the bridge straight down, the load on the bridge would be carried outward along the curved part of the arch. In that way, the load will be transferred equally to both sides of the arch so the bridge doesn't topple over post·haste, but again we wanted to make sure that the bridge had extra reinforcement so we used a triangle pattern. On the two sides of the line in the middle, there is a triangle pattern going across. focused in one place, so the bridge collapsed. Our third idea was to make a beam bridge. Beam bridges consist of a horizontal beam that is supported at each end by piers. The weight of the beam pushes straight down on the piers. As a result, beam bridges barely span more than 250 feet. This is because as the length of the bridge increases, the weaker the bridge becomes. With the beam bridge, we could get a clear idea of how we should position each of our straws because if we positioned our straw horizontally face down, our