West Point Bridge Design

After building the model truss and learning about the forces acting on a bridge, we were told to design our own bridge using West Point Bridge Designer 2016. The catch was that we had to do it for the lowest price. Although I tried 5 different bridge designs and my last design had 77 iterations, I finally brought the price down to $175,850.09. Here is a photo of what my final bridge looked like:

How I lowered the price:

1. Even though it is counterintuitive, if I had to increase the size of one piece because it wasn't strong enough, it was more cost effective to change multiple members to the same dimensions. If I were building this bridge for real, manufacturing pieces of many different dimensions can get expensive.
2. Suspension bridges are not the way to go!
3. It's all about trade offs- excavation costs a great deal of money up front, but by decreasing the span of the gap, you have to use less materials, which lowers the cost.
4. Furthermore, when you decrease the span of the bridge, a middle pier is not needed which decreases the cost even more.

What I liked about the software:

I thought that the software was very user friendly and served as a good first bridge simulator. I enjoyed how they provided sample designs because it gave me a good place to start. When you played the simulation, each member turned either blue or red depending on whether it was under tension or compression, which was also helpful.

What I disliked about the software:

There was nothing major that I didn't like about the software. However, it was important to make sure you were using the 2016 version and not the 2014 version.

Tips:

1. Make the bridge symmetric: if the sides are mirror images of each other, you know that if you change one member, you have to change the corresponding member on the other side
2. Don't be afraid to play around with different variation!: using the arrows on top, you can switch back and forth from different iterations and you can always click the undo button
3. Look at the members list and member details on the right side of the screen: you want to try to get the compressive/tensile force value as close to 1 as possible. The member details tab will give you a graph of the strength vs length of a particular member.