Analysis Process

               When analyzing a bridge that an engineer is designing, many factors play a role that you need to take into consideration.  Bridge Designer is great when you are playing around with K’nex pieces or if you want a general idea of the compression and tension forces, but it would not work for a real bridge.  Bridge Designer does not take into effect the load of the bridge itself, the weather, or any other outside forces acting upon a bridge.  I personally would not trust a bridge that was more carefully thought out and experimented/analyzed on.  I also think you need to apply more than a few trig and physics equations to a bridge design in order to make sure it will be a safe, efficient bridge.  

 

                For our class, I would like to take a look at the gusset plates that we are using.  It is hard to figure out which ones are strongest when you can only test your bridge once in class.  I also wish there were general guidelines to using K’nex pieces, such as ‘the longer the members, the stronger the bridge’ and so forth.  I have no idea whether that is actually true or not, and again, there is not a lot of time for experimentation.  Some choices you can make are common sense, but for someone who is new to bridge designing, there is an awful lot to learn.  I also think it would be helpful to have a way to analyze the differences between a two foot bridge and a three foot bridge.  We are not exactly sure that what we did for our two foot bridge will be efficient when lengthening our bridge.  There are just a lot of unanswered questions. 

                Last week in lab Melissa and I worked with Bridge Designer and tried to calculate the forces on our K’nex bridge three foot design.  However, we could not get this to work because “members+3 did not equal 2*nodes”.  This proved difficult to fix since our bridge was centered about a single node, not a member.  It was frustrating to tamper with the design on the computer and find something that would work out similarly.  In the end, the design is simplified in my A3 post because I was really running out of designs to try that still resembled our bridge.  This week in lab I hope to continue learning about the design process and come up with ways to improve the design we already have.