File Folder Bridge Construction

The Bridge:

Our assignment was to create a truss bridge out of file folder material, and we would test to see how strong it was by placing text books on top of the bridge, but first we weighed the books and progressively put the books on top until the bridge broke. First, we had to build the bridge, though. We started by placing the given plans underneath a piece of wax paper and on top of a square piece of styrofoam, and we placed pins in the corners of the plans and wax paper and styrofoam so the plans would not move and we could glue the pieces together on top of it without it being stuck to the styrofoam. We then followed the instructions to create various lengths and thicknesses of strip of paper, and tubes that would would create (which are all listed on the material list below). We also were given little pieces of paper with numbers on them. They had different shapes, and would act like the joints of the bridge, and the numbers corresponded to the numbers on the plans. We then glued all of the tubes together and glued the strips where the plans said to on the diagram to the numbers. After we had glued all of the strips down, then we had to glue the tubes to the numbers that the instructions told us. We had to make sure the right tube size was going in the right place in order to make our bridge all fit together. The tubes were harder to make fit together, but when using glue and excelerant to make it dry faster and stick together, it made 3 parts of the bridge fast to build. We then turned the pieces upside down and glued the top of the side pieces to the middle piece, and also glued the little piece that hangs off the middle piece, on to the sides of the bridge. We then reinforced the bottom side of the bridge with more tubes to go across the two sides of the bridge. We then finished our bridge and were ready to test its strength. We measured the books on the scale and in total were able to hold 3 textbooks. The 4th textbook made it break directly in the center of the bridge after a few seconds of it being on there. Overall our bridge was a success, especially being made of a material as weak as file folder paper, and it held 5 kg.

Instructions:

Building the Bridge:

Testing: