Week 10

In last week’s lab we put our final three foot bridge design into COMP2. During the lab the week prior to COMP2 we were able to get our three foot bridge support 42.3 pounds. With this amount of weight the cost to weight ratio of the three foot to be around 9,000. Unfortunately during the competition our bridge was only able to support 31 pounds. The cost-weight ratio sky rocketed to 12,300. This made a huge difference. The bridge failed exactly where it did the previous week at the member where the over truss connected to the rest of the bridge. This bridge cost about $380,000 and I wish that our bridge went like out test did but overall our bridge did a lot better than our 2 foot bridge which is good because it was a good improvement.
         Over the course of this class there has been a ton of information that will help me out in my future endeavors. I learned a great deal about bridges, especially trusses. Also I learned about physical modeling them and weight distribution. The least beneficial portion of the class for me was the bridge design program that calculated compression and tension distribution. I did not find this program to be very helpful and I thought it made everything a bit more confusing than necessary. I think it would be better if WPBD did what that program did. I absolutely love doing anything hands on so being able to build my own bridge with k'nex it was great. I actually got lost a couple of times just coming up with different designs. To improve the class I would have there be more time for people to test their bridges before doing the competitions. Also, the constraints for the competitions should be made so there are no loop holes or ways to bend the rules at all. Finally, I would have each team to have to tries in the competitions in case of any mess ups that may make the results more accurate. Overall this course was a blast I had a ton of fun and took a lot from the course.

-Robert LaChance

Week 10 Blog Post

         Last week in lab, we tested our final three-foot bridge design. During week 8, our three foot bridge was able to successfully support 42.3 pounds. This result produced a cost-weight ratio of approximately 9,000. Unfortunately, last week it was only able to support 31 pounds. This resulted in a cost-weight ratio of 12,300. It is clear that the ten pounds made a great difference. The bridge failed right under the raised truss, similar to the previous week. This final bridge cost approximately $380,000. The cost to weight ratio is acceptable but I would prefer it was able to hold more. Overall, I'm happy with our final result.

         I learned a lot over the course of this class. I learned a great deal about bridges, especially trusses, physical modeling and weight distribution. The least beneficial portion of the class for me was the bridge design program that calculated compression and tension distribution. I found this program to be very confusing and frustrating. I would much rather prefer to calculate these properties by hand using trigonometry. The physical modeling segments of the lab and working with Knex were my favorite parts and the most beneficial for me. I always seem to learn more through hands-on working. To improve the class for future students, I would suggest opening a few more bridge testing stations. Once the time came where groups began to start testing, the stations became very crowded and getting the opportunity to test was often a struggle. Other than that however, the course was very well organized and I learned a lot.