The first semester of the Steel Bridge project is all design. There is a 40 page set of rules that we have to follow. Well, we finally have the design mostly complete-just a few more changes, probably. Below is the initial design.
The arch on the top was intended to reduce deflection, which it did, but the bridge weighed over 400 lbs. Way too much weight. So, we got rid of it, and it dropped a couple hundred pounds. Removing the arch will also make building the bridge during the competition easier and reduce the time it takes to build it. The new bridge is below.
The pink squares are the connections between the members. They are basically interlocking joints.
In the program, all of the design constraints are met. The maximum vertical and horizontal deflections are not exceeded, and the weight is relatively low. We will only really know if the physical bridge works after we build it. Our welds have to be strong and neat which will be a challenge since only 3 of us know how to weld, and we’re not the best. However, I’m confident that the bridge will be successful in the end we will have a lot of fun building it!