Week 9 Post

In lab last week our group worked on our 3 foot bridge. Compared to our 2 foot bridge we had drastically changed the outlook of the entire bridge so we could cut down on the bridges cost which was our main issue in the last competition. For this bridge we also had to have a 2" by 3" passageway so cars and trucks could have space to cross our bridge. When we first came across this challenge it seemed to pose a problem but after some tweaking and playing with certain ideas we came to our basic design. One of the main goals we wanted to do for this bridge was to remove any grooved gusset plate that we had and find a way to replace them without getting too far away from our original design. When we removed the grooved gusset plates it immediately made a huge impact on the total cost of our bridge and it gave us some extra money to make other adjustments to improve the strength of our bridge. When we tested our 3 foot bridge it was able to support 42.3 lbs. which we were a bit shocked at proud of at the same time. Seeing as both out 2 foot and 3 foot bridges cost about the same and our 3 foot bridge held more weight than our 2 foot bridge we knew we were on the right track and have a chance to have the most cost effective bridge design. We hope to do well in the competition and maybe get atop the board and get some extra credit.
This term is almost and when I think about what I have learned in this course. I did not know a ton about how bridges actually functioned and how, but after this course I have a better understanding of them. I learned a lot about why truss bridges are a very commonly used bridge structure and how they are able to disperse weight on their members to hold the tremendous amount of weight that gets put on the each and every day. Also, I learned that the bridges we see out in the world are not there because someone just decides to come up with a plan for a bridge that would be the best bridge ever, but you have to take time and design a bridge that has a good amount of strength to it and is cost effective to build. Especially for our competitions, the cost-to-weight ratio was how we determined the effectiveness of our bridges by comparing the bridge's overall cost to the maximum amount of weight it can support. Weight distribution is a very important skill that was also taught to us in class. We used set of calculations to determine how the force, either tension or compression, would be dispersed throughout that entire structure. This class was definitely a good class to have because the thing I have learned and the skill set that I now have for being in this class will help me in my future endeavors.

-Robert LaChance