Bell Weekly Blog- Week 7

In the previous week, our group kept the design of our bridge that we had made in week 5. We felt like our design had the best cost to strength ratio possible. In week 6, our group actually put our design to the true test. Our bridge held a total of 39.2 lbs. It also broke between the joint and the member, as expected. In the coming week, our group has agreed to keep the design that we currently have. This week in lab, the group will start to construct a bridge that spans 3 feet instead of 2 feet. We have agreed to use the same design as the 2 foot bridge because we feel that the design will suffice with another foot to add on. We have also agreed to make the bridge higher for maximum strength. Our major accomplishments for the week have been being constructing a bridge that was able to hold a lot of weight. The only issue that our team might have would be the argument over different designs. On person might think a certain design would be better while the other two members don't.

When we were using WPBD, the group was able to analyze what pieces had more tension/compression and exactly how much. Based on these block box answers, the group was able to change the material and thickness of the member accordingly. Once we started to use K'nex, the only thing we can use to analyze anything was with our eyes. we could physically see where it broke, but that's about it. Another thing that would be nice to have with K'nex is ability to choose the length of the members, the amount of members attached to a joint, the angle at which you can connect members to joints etc. But, none of that is possible, because everything in K'nex is fixed and can not be changed. If I could choose any results to show up as numbers, I would choose the breaking point between the member and the joint. 99/100 times, the breaking point will occur at the connection point between the joint and the member. I wouldn't really worry about buckling too much. The strength of the solid plastic is far more than the strength between the member and the joint. As seen in our test in week 6, the only numbers we would like to view are the connection of the joint to the member. More specifically, we would like to see the block box answer for the joint to member connection for the second joint in on the bottom on the bridge (total of 4). These 4 points seem to be the first to give throughout all of our tests.