We constructed a simple bridge using an index card and two wooden blocks. Initially, the bridge was quite basic, but we gradually enhanced it by adding trusses, arches, and crossbars. Each modification aimed to improve the bridge’s stability and load-bearing capacity.
We tested the bridge’s stability three times, each with different results. As we made the structure more complex, the bridge's ability to bear load increased significantly. The trusses provided additional support, the arches helped distribute the weight more evenly, and the crossbars added rigidity. These adjustments collectively strengthened the bridge, demonstrating the importance of structural elements in engineering. The experiment highlighted how incremental changes and reinforcements can lead to substantial improvements in a structure’s performance.
This initial bridge design consisted of only a paper in between the two wooden blocks. As shown in the video, the bridge collapsed rather easily, supporting only 5 hex nuts. The main point of failure was the bridge not being able to support the weight of the nuts as it dipped in the middle. This amount of weight from the nuts caused the sides to lift upwards as the whole bridge bent in a U-shape.
For the second attempt, 2 trusses were mounted onto each side of the bridge, parallel from each other. This proved to be initially successful as the bridge succeeded in supporting 6 hex nuts. As the 4th to 6th hex nut was placed on the bridge, the 2 Truss structures started to warp outward and the bridge collapsed on the 7th hex nut. The truss structures proved to be a viable strategy for the bridge to hold more weight however further improvements were needed to firmly secure the trusses.
In our groups final attempt, we attached diagonal crossbeam structures and added vertical supports to the trusses to secure them to the bridge so that it would not warp. The additional implementations allowed the bridge to hold 9 hex nuts, collapsing on the 10th one. The beams and vertical supports aided in distributing the force across the bridge, allowing it to carry more hex nuts than our previous attempt. If we were to add any further modifications, it would be to attach a beam that connects to the two parallel trusses so that they would be mounted together and not bend outward.