End of week 2

Everyone’s bridges are beginning to come together now as we finish off the second week of building. I have finished one half of the truss system for my bridge, and Chris Becker has created a large section of his bridge as well. Both of us decided on a triangular shape but went about designing it in completely different ways. Mine consists of two truss systems connected with beams while his is a series of layers, each smaller than the last, connected by strong vertical supports.

Chris Becker's Bridge:

My truss system:

In the last two days I have finally managed to complete one of my trusses and begin the second. Once I have finished constructing these I will connect the two with the roadbed and beams I mentioned earlier. So far, I am very happy with how the bridge is turning out, although learning as you go requires some patience.

Chris has been doing very well as well. He just recently managed to construct the pyramid top to his bridge, something that should add considerable stiffness to the design but was difficult to build. In the close up below you can see how he managed to interweave two triangle to create the three-dimensional shape.

- Turner Bohlen

Week 2 of Construction

Over the past week and a half I have been constructing a balsa wood bridge with a triangular design. I was able to construct the four main triangles which make up the bridge with little to no problems, but this week I have encountered my first real mistake. I added supports to the bottom of each triangle, thinking they would fit perfectly in between the blocks which our bridge must rest on. After adding the extra supports I realized that i set them millimeters too wide and they did not fit in between the blocks as I planned. In order to correct this problem without spending a lot of extra time taking them off, cutting them, and re-attaching them, I am going to extend off of the support. This extension I’m adding should allow my abutment supports to work properly and at the same time give a place for the bridge to rest on.

My bridge supports not fitting in between the blocks:

Solution:

One of my fellow peers, Scott McDougall, is taking on the task of constructing a balsa wood bridge in a completly different way from me. Insteaf of making a bridge which is made up of only stright pieces of wood, he is incorperating arches into his design. Although this is a tough task, he has been able to follow through with it with ease and nearly no mistakes. He has already created the arches for his design by soaking pieces of balsa wood in warm water and then tacking them down into their desired shape. This method has worked well, and he reports to me that the arches are exactly how he would have like them.

Scott's arches being formed:

-Dylan M.

Week 1 of Construction

After the first three days of construction I have worked on forming my arches and creating the bottom of my bridge deck. I have successfully made three arches and am in the process of soaking one more. In order to form the balsa wood I had to soak it over night in hot water, and then I taped and tacked the wet pieces into my arch. While waiting for my arches to soak, I have started to cut many of the pieces I will need for rest of my construction.

Also my classmate Aaron has made great progress on his bridge as well. Although he is not done, he is very close to completing his very sturdy bridge deck. Aaron just needs to finish making the deck on which the weight will sit and then he will have middle bridge deck out of the way. Like myself, Aaron has also cut many of the pieces while waiting for his deck to dry.-Chris T

Stuctures & Material Science!

Welcome to our blog! We started this blog to document the construction of our balsa wood bridges. During the next eight weeks we plan to show you pictures and tell you a little bit about our progress as we build these great structures that we have designed ourselves. At the end of the semester we plan on testing these bridges to see how much load they can withstand. We hope you stop by periodically and check out our progress!