In this project, I had to design build and test a 16 inch long truss bridge. The goal of this project was to teach you how bridges are designed and built, and show the process of how bridges are designed and made in the real world by professional engineers. Bridges are used all over the world and it is a very important skill to know and understand how the physics of bridges work and why bridges are made how they are made, and that’s what this project is for. First, I had to come up with a possible design for the shape of the trusses for the bridge.
Then I created my bridge design on WestPoint Bridge Builder and tested its ability to hold a truck, and created the design on MD Solids to see the forces acting on the bridge. Next, I built a model of the bridge using popsicle sticks and glued all the pieces together. After the bridge was complete, I tested the bridges strength and ability to hold things and recorded the results. The point of this project was to learn how to design, test, and build bridges sufficiently. Design Designs and ideas for possible designs are the first step of building a bridge.
First, Preliminary sketches were made in an engineer’s notebook of four possible designs for a truss bridge. This is a screenshot of those sketches: Then one of the preliminary sketches was selected to be the design for the final product. Next, the bridge design had to be made on WestPoint Bridge Designer. The design was then made on the program and the bridge was to be made as inexpensive as possible while still supporting a truck. The design was finished and screenshots were taken of the bridge. These are some screenshots from WestPoint Bridge Designer:
Last, the bridge design was made on MD Solids to show the forces that would be acting on the bridge. This is a screenshot from MD Solids: Construction Next, the bridge had to be made from popsicle sticks. First, the side outline of the bridge design was measured out and drawn on paper and the paper was glued to a square of cardboard. Then popsicle sticks were cut with shears to the length they needed to be to be glued together. The cut popsicle sticks were then glued together and taped down to the cardboard in place for the glue to dry.
Once all the glue was dry, the side was finished. The process for the side of the bridge was repeated to make the other side. Once both sides were completed, the two sides were glued to a wooden rectangle that would be the road of the bridge. Then, cross supports made out of popsicle sticks were glued along the top of the bridge. After all the glue was dry, the construction was complete. This is what the bridge looked like when it was completed: Measurement Once the bridge was complete, the bridge needed to be tested.
The bridge was measured to be 16 inches long and 2 inches tall. The bridge was also weighed out to be 85. 0 grams. Next, the bridge was to be tested on how much force it can take with the Structural Stress Analysis machine. First, the bridge was put into the machine and screwed in to the place it needed to be. The case was then closed on the machine and the test was started. The machine pulled down on the bridge until it broke, measuring how much force the bridge can withstand without breaking.
The machine recorded the data collected and made a graph to show how the bridge performed under stress. The bridge at it’s best held up 44 pounds of force. Here is a screenshot of the graph that the machine produced: Analysis Overall, I did very well on this project. I created a design for the truss bridge that allowed the bridge to be strong and hold a lot of force. On Westpoint Bridge Designer, I was very close to making my bridge design cost under 200,000 dollars and still holding up the truck.
My bridge on westpoint costed 204,389 dollars and it held up the weight of the truck. My bridge that I constructed out of popsicle sticks also was very good. It held up to 44 pounds of force, according to the Structural Stress Analyser, and my bridge was one of the strongest in the class. This project taught me what the process is to design bridges, What types of truss bridges are the strongest, and how real bridges are constructed and tested. This project was pretty fun for me and it taught me a lot about truss bridges.
Courtney from Study Moose