Project 2, Team A3

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Synopsis of Bridge Scores

  • α squad score: 1.498662E-6
  • Ω squad score: 2.872116E-6
  • Current best team score: 1.42911E-6

Team Members


Alpha Squad

Alpha Squad (Jack and John) based their design on the principle that arches are the strongest structure in nature. They started by making a semicircular hole in the center of the design, which created a main arch. Then, to minimize the surface area used, they cut curved, triangular holes into the outside section of the bridge. This made a series of branching archways that spread the stress towards the outside as opposed to downwards. Then, they tested their design with COSMOSXpress and found that most of the displacement was occurring at the center of the top crossbeam and most of the stress was concentrated in the inside corners. To minimize the displacement in the center, they thickened the center of the top crossbeam by reducing the radius of the circle used to create the main arch. To keep the stress from building in the inside corners, they used the filet tool to round off the corners. The resulting design is shown below, and has a score of 1.498662E-6. A3alpha.jpg

Omega Squad

Omega Squad (Kevin and Will) made a design that was inspired by the Mickey Mouse sample bridge. However, instead of using one ring, they used three, and connected the rings with a series of crossbeams. This was meant to spread the stress from the top beam to the sides, since the rings would try to spread sideways when compressed. When tested, the design showed a great deal of displacement in the middle. To fix this, they filled in the center of the middle ring, which was meant to decrease the flexibility of the center portion of the bridge. The resulting design is shown below, and has a score of 2.872116E-6. A3omega.jpg

Final Design

Since the Alpha Squad bridge scored much lower, the final design was based off the Alpha Squad bridge, but borrowed some ideas from the Omega Squad bridge. One of the borrowed ideas was the idea of filling in rings to increase stability. The small circular holes in the Alpha Squad design were thus filled in, which increased the surface area, but the gain in S.A. was more than compensated for by the decrease in displacement. Adding a support beam in the center only seemed to hurt the design, though, since it transferred stress straight down, instead of deflecting it sideways as the arch did. The top beam was also thickened towards the sides to make the side sections the same thickness as the center section of the top beam. This made the surface area the maximum allowed (6.70 square inches) but it was compensated for by the very low maximum displacement (2.133 in). The resulting design is shown below, and has a score of 1.42911E-6. A3 bridge(final)pic.jpg

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