Analysis Desires

When designing a bridge on West Point Bridge Design, it tells us what pieces fail and how much tension and compression is exerted on each piece.  I feel that this information would be really helpful when designing our K’nex bridges.  It is a completely different experience to design a 3D bridge and also including the top and bottom designs, rather than just the side pieces.  We have no idea of how our bridge is going to work until we actually test it.  This makes us put a little more effort into our design, but it also means we might not create the most effective or efficient bridge because we are not able to participate in trial and error type experiments.  If we knew before hand which pieces were most likely to fail, we could design our bridge differently before actually participating in the class competition.  I’m not sure how this could be done, but I know it would be helpful to have the tension and compression numbers known so we could build our bridge to its max potential. 

Last week we tested our bridge in class.  It did much more poorly than we expected it to.  It only held a total of 17 pounds.  It broke right on the edge of the bridge; the piece that was on the horse holding the weight of the bridge.  We did not expect this.  We thought that the reason it would fail would be because the gusset plates would slip apart because they seemed like the weak pieces of the bridge.  We decided that we should scrap our bridge and create a new design.  In class we decided we should go with a square shaped bridge instead of the trapezoid we had originally built.  We think this will help disperse the weight of the bridge off of the end points.  We hope to test our new design in class this week with better results.