Check out our IEEE research paper for more information!
Overview
This week, we were tasked with building 3 bridges: 1 of which was built by a simulation, and 2 of which would be physically rendered and tested. In order to encapsulate the full experience of civil engineering, we had to design and render a bridge with a limited amount of materials in order to simulate constraints of cost and time in real deal engineering. We also had to design 2 bridges: one of which was to show how to design/test bridges in simulations, and one of which would be rendered by a different group in order to simulate communicating ideas from one person to another.
Material Engineering
Material Engineers are in charge of designing materials with specific properties for the task that they need to handle. They do so by synthesizing materials and analyzing their molecular structure and composition in hopes of designing a material fit for the task at hand.
Civil Engineering
Civil Engineers are in charge of designing any buildings and projects that are put into effect across the city. They handle anything from skyscrapers to irrigation systems, and are useful throughout the entire designing process of a building. They plan, design, and supervise the engineering process of the structure they are in charge of.
Design Process
Simulated Building 1
Our first project was to design a bridge that would span 12 meters above water with 2 lanes of travel while using carbon steel reinforcement. In order to do so, we built a typical Pratt superstructure and substructure in order to ensure the bridge's safety when cars were crossing the bridge. Our final design cost about $450.000 to build. A picture of it is shown on the right.
3D Printed Bridge
Our second project was to build and design a bridge in order for a partner group to render in a 3D printed format. To do so, we copied our physical rendition of our bridge design (seen below) and asked our partner group to copy it so we could get a feel for how sturdy our bridge design would be.
Physical Bridge
For our physical bridge, we were given 15 planks (3 feet by 3 inches, 1/8 inch thickness balsa wood), 150 sticks (1/8 inch by 1/8 inch, 3 feet long balsawood), 15 hot glue gun sticks, and 2 glue guns. The bridge had to have a 4 foot driving surface and at least a 7 inch span to accommodate the car that would drive across. There also had to be a 1 foot distance between the tables and the bridge to allow for proverbial ships to cross under the bridge. We started off by experimenting with the planks and sticks to ensure which configurations of sticks would be th e most structurally sound. We ultimately decided on a Pratt truss and a bridge very similar to the 3D Printed Bridge that we designed. However, we still had to design the supports that the bridge would rest on. We designed on creating a square design with Pratt trusses to hold the corners together in order to make the supports structurally sound. We cut the boards into fourths to create a corner piece to rest the bridge on. After using all 15 planks, about 50 sticks, and all 15 glue gun sticks, this is the final product shown below:
This is what the final result of our bridge looked liked, after two days of constructing it. We have the pillars on the side, which we decided to make into a rectangular prism. Additionally, we added a truss design to the pillars to make it more sturdy. For our bridge board, we realized that the board itself was not sturdy, and therefore we added supports on the bottom to help with the sturdiness. We also added a sub-scripture on the bottom, which was a truss design, to add extra support. Finally, we also had a truss at the top, which helped balance out the strength-to-weight and stiffness-to-weight ratios. Overall, we were extremely happy with our bridge and we were excited to test it out with the bricks, the next day.
In the end, we were only able to carry 6 bricks across our bridge before it collapsed. We were disappointed in this result, as we were hoping for our bridge to carry at least 7 bricks. We believe that our fault was in our substructure and the pillar on the right side of the bridge, as that was where the bridge originally cracked. We also believe that a second layer of trusses and expanding our trusses vertically, creating a support at the high point of our bridge would decrease the stress put on our bridge.