Get ready ladies and gentlemen because over the next two weeks you are going to explore, design, build and test a popsicle wood bridge! Every other year students in middle school physics construct popsicle stick bridges as part of the Science Central Bridge Building Competition. It is an engineering based project with elements of computer aided design, physical construction, pressure testing, and analysis. A full activity guide and corresponding documents for this project can be found below!
- A. Explore Key Aspects of Bridge Design (2 Weeks)
- B. Engage in Computer Animated Designs (3 Weeks)
- C. Engage in Physical Construction of Design (3 Weeks)
- D. Example Bridges from years past.
A. Bridge Design Research (2 weeks – one day each week)
As a people we are heavily reliant on a solid transportation infrastructure. We use a system of highways, railroads, airplanes, and ships to move goods, materials, and ourselves from place to place. One very important aspect of our transportation system is its ability to adapt to the various terrains that our great nation has to offer. Roads, railways, and even ships are all influenced by bridges in one form or another. Your job over the next two days is familiarize yourself with different aspects of bridge design and function.
1. First, I want you to explore the different forces, loads, materials, and shapes that affect a bridge’s ability to function properly using the PBS Exploration Activity!
2. Please complete the Bridge Research Companion Document in conjunction with this activity. This will be turned in ONLINE via Google Drive for credit!
3. Some bridges historically have failed to take into consideration certain design aspects and have failed. Below are two YouTube videos that demonstrate bridge failure. Note: Some YouTube videos are blocked on school servers and will need to be viewed outside of class.
4. Once you have completed the PBS activity review the following website as a reference. You will want to use it when designing your bridge! Your focus should be to look at the many different truss styles. This can be found a ways down the page. You will use one of these many styles as inspiration for your own bridge!
5. Lastly, take a look at the YouTube videos and imagery below. This is evidence that bridge design and construction is important and when certain elements are overlooked bad things can happen!
B. Computer Design (3 weeks – one day each week)
As part of this adventure, we will be using software that allows us to construct and test our own bridge designs. You can get the software from Mr. Bornheimer to use on a school computer OR you can go here to download it on your own computer!
The goal is to design a truss style bridge that can span 24+ inches minimum! Be careful, the gap will be 24 inches therefore, you will need to think about making your bridge longer! You may want to start with some simple truss designs (look at Part A #4) for inspiration.
- You must be able to provide the teacher with a known truss style (i.e. Pratt, Howe, Warren, Warren w/ Verticals…etc.) that inspired your bridge design.
- You must have a design that meets the 24+ inch gap requirement. Your bridge should not exceed 30 inches.
- The tallest point on your bridge can be no greater than 12 inches.
- You must draw a scale drawing of your bridge design so you can build it!
C. Physical Bridge Construction (3 weeks – one day each week)
- Exacto Knives (Tool)
- Scissors (Tool)
- Elmer’s Yellow Wood Glue (Building Material)
- Popsicles (Building Material)
- Wax Paper (Tool)
- Bridge Sketches (Tool)
The plan is to place the wax paper over top of the bridge sketches so that you can see your sketches through the wax paper. Next, you will cut pieces of popsicle sticks to match the lengths designated on your sketch. You will place the pieces of popsicle sticks on the wax paper so that they line up with your sketch. Once you have several pieces in place, you can start gluing. You will want to begin gluing AS SOON AS POSSIBLE. This is the most time intensive part of the construction but also one of the most important. You do not want your bridge to fall apart because one simple joint gave out!
D. Model Testing (In Class or at the Science Central Bridge Competition)
Here is a YouTube playlist showing bridges being tested in years past. Note: Some YouTube videos are blocked on school servers and will need to be viewed outside of class! Also, these bridges were built with different materials but the ideas are the same!