Musical Plates: What Can I Build On?

2009-08-31T06:12:00.000-07:00

Engineering Application: Keeping Afloat

(from CIESE: Musical Plates project: http://www.ciese.org/curriculum/musicalplates3/en/teacherenrichment4.shtml)

Land has been donated to your town to build a computer-technology building. The architects have designed a structure but it is not considered earthquake resistant. Your class will act as an engineering firm that would like to be subcontracted to modify their design to make it earthquake resistant. In order to get the subcontract your engineering firm must propose the most effective and economical design modification. Your class will divided into several design teams and each team will submit their ideas to the project manager. Then, as a class or engineering firm, one plan will be selected and used for the proposal.

The architectural firm will provide you with a scale model of their design and a substrate that will replicate the substrate at the building site. You cannot modify the building design in any way.

Only particular materials are available and you will be challenged to be as economical as possible. Therefore, while designing the building your team must consider the materials available, the cost, the substrate that the building will be built upon, and the fact that the building will be in an earthquake zone.

The design team will be responsible for agreeing on a design, drawing the design to scale, listing materials and cost, and writing a proposal selling the team design idea to the architect on the project. Good luck!

Key concept
The ability of buildings to withstand earthquakes is dependent on structural integrity and the substrate on which the building is constructed. During an earthquake, the underlying substrate tends to compact; a process termed liquefaction. This lesson will challenge you to develop design strategies capable of withstanding liquefaction.

Objectives

Explore how earthquakes cause structures to move
Understand how the substrate cause buildings to fail
Discover what variables affect building stability
Engineer a model building to withstand earthquakes better

Step 1: Create a blog

Create a team blog where you will record all your activity on this project. Next, post a comment in THIS blog and share the address of your team blog & your team’s name so that others can link to your blog and review your progress.

Step 2: Establish a testing procedure

Watch a demonstration for some ideas on how to establish a consistent procedure. Post comments in your blog outlining your methods and the ability of the original design to withstand your testing procedure. What were the results of your tests? What level of precision were you able to reach in your testing?

Step 3: Peer review of other team's testing methods

Select another team's blog from the posts below and follow the link to their blog. Find their testing methods discussion and read through it and even try it! What did you like? What problems can you foresee? Give the team your feedback on their blog.

Step 4: Test the architect’s model

Test the ability of the original design to withstand your testing procedure. How many tests did you run? What were the results?

Step 4: Design, Test and Reiterate

As a team brainstorm some ideas to improve the building’s ability to stay level. See the materials list to determine what choices you have.

Available materials:

Aluminum Foil, $35/ 100 sq cm
Rubber band, $30 each
Popsicle sticks, $75 each
Paper Clip, $20 each
Tape, $10/ 5cm

Remember you cannot:

alter the architect’s building design
use any of the volume inside the building
attach anything to the sides of the plastic tub

Next choose the best idea, build and test that idea out. Write down the results of your test in the Design Log. Also, calculate a Percent change for your design:

Percent change = [Original - New]/Original X 100

Original = amount off-level without any modifications
New = amount off-level with new modifications

If your answer is positive then you have successfully improved the design. Congratulations!

Next, consider the additional cost of the building due to these suggested changes.

Reiterate the group’s design ideas. In other words, attempt to improve your design for the next trial. Can you improve the structure’s ability to withstand a 20 second tremor? Can you make your design modification more economical?

Step 5: Peer review another design team’s work

Find a team to partner with and exchange blogs and models. You will run your partner's model through your testing procedure to see how well it works. How well did the model withstand testing? Any improvements you would suggest? Any questions you have for the team? Go to your partner's blog and provide feedback to those questions there.

Step 6: Final Project

Prepare an engineering report that reflects your work and illustrates your team’s most economical and viable idea for improving the original building’s ability to withstand liquefaction during an earthquake. Remember, the group will be responsible for listing materials and cost and writing a proposal selling the team design idea to the architect on the project.