Week 4 - WPBD

In my opinion the West Point Bridge Designer (WPBD) program has many faults. While it is a good reference and teaching tool especially for understanding truss’s and tension and compression, one should not use this to create a bride prototype. First off, this program exaggerated the downward displacement a bridge experiences when a load is applied, basically making every bridge look unstable. It also does not allow for one to create the top truss connection beams. This part is just as essential to the bridge. Two huge items that is also not taken into consideration is the gusset plates and weather forces. These also can make a big difference in the bridges stability.  Another thing I noticed was that it allowed for bridges to be made, that in reality are unsafe. There is not a single large bridge that I can think of that does not have some sort of upper safety barrier. Especially nowadays not a single company would allow for a bridge to be made without some sort of upper protection beam. WPBD allows for bridges with no top beam or support to be created and pass a load test when in reality it is just not safe. Overall, I think that the WPBD is a good learning tool, not a program for actual bridge testing and production.

Last week in lab we discussed bridge production on WPDB and how cost could be reduced. We were challenged to submit the cheapest bridge possible that was still considered “structurally” sound. At first thought this challenge didn’t seem difficult but considering the fact that my teammates and I all made somewhat expensive bridges this task was more difficult than anticipated. I tried making several new bridges from scratch but this failed quickly. Ultimately the best choice became altering Chelsea’s bridge and slightly changing the structure and material according to the values yielded by the load test. I was able to reduce the cost by more than $100,000 and if given more time I could have reduced it even further by re-creating the same structure with shorter beams.