Engineering Design Challenge for Students Using CARDBOARD

Introducing kids to engineering can be difficult, especially with limited budgets. However, hands on projects are extremely memorable for students and increase collaboration between students. Thus, I propose this simple project, in which students build a bridge made only out of a sheet of cardboard and hot glue. In this Instructable we will follow the work progress of a single group. This project was created by a high school student to help educate younger grade levels.

Supplies given per group:

1 x Scissors

1 x Hot Glue Gun

1 Sticks of Hot Glue

1 Sheet of 11" x 15" cardboard

1 x Pencil

Supplies Necessary for Testing:

Rope

Bucket

Weights (I used the smaller gym plates although any type of weight works)

Bridge a 9" gap by building a bridge to connect the sides of the two table. When your bridge is ready, weights will be placed over your bridge until the bridge experiences a structural failure. Your objective is to achieve the highest load bearing to weight of bridge ratio out of any of the groups.

You will receive a single scissor, hot glue gun (with glue), and a sheet of cardboard. Notify the teacher when you are ready. Good luck!

The group began discussing ideas for the bridge. Then, they drew basic shapes on the raw cardboard as a plan as for what to cut out. They glued together whatever idea they came up with.

Unfortunately I do not have pictures of this part, but it is fairly simple. Place two tables 9 inches apart from each other. Place the bridge on the lips of the two tables and string over the bucket onto the bridge. Keep placing weights into the buckets until the bridge experiences permanent structural deformation. Mark the weight at which it deforms for later reporting.

You may want to give the student a new sheet of cardboard for this section. The group completely redid the bridge but maintained the same core design idea, struts connecting two planes. However, this design had full length of struts and accounted for cutting errors.

The group completely restarted after the destruction of their previous model. They realized that when the force was applied onto the bridge, the struts did little to prevent breakage and it would better for the long columns to be placed perpendicular to the weight, depicted in the image above.

To further increase the ratio, instead of increasing load bearing, you can decrease the weight of the bridge. You can do this by pocketing the bridge and creating holes while maintaining the same structural integrity. To finish the project instruct your students to create a simple lab report, including:

• images of every iteration from different angles
• calculations of its load bearing to weight ratio for every iteration (remember to account for units)
• possible improvements

I try to not make this to wordy or cumbersome as to not discourage them from the task.

Encourage your students to explore the possibilities and try weird, whacky structures. Remember, the goal is to learn. However, competitions are always fun, so crown a victor. It can either be the most creative design, best ratio, or some other metric. The high score for my group was in the hundreds with a 61g bridge holding up 30000 grams!