TEACHING CLUES AND CUES
This design may take a
full class period.
Trace the structure’s
outline with a pencil or
pen, put glue on the
cardboard along the
outline, and press the structure down
firmly. The hot glue may melt the
Styrofoam if applied directly. Warn
students not to drip the glue on their
hands.
This activity will
generate considerable
excitement. Let students
enjoy it, but maintain
order to be sure
4. Hand out all the materials except the glue guns, being certain every
team receives the same set of materials. Allow some time for
experimentation with the materials before students finalize their load
path diagrams. Be sure students in each group have drawn force
arrows on their design (step 3) to predict how they think earthquake
shear forces will travel through (or load) their structure.
5. Establish how much time the SETs will have to build their
structures, either by setting a uniform time for all or by inviting each
SET to commit to a time limit and appoint one member of the team to
keep track of time. (This could simulate the process of bidding on
contracts, and add an extra element of competition.) Then give the
signal to begin.
6. When building is finished, use one of the models from Lesson 1 to
demonstrate fastening the structures to the center of the cardboard
bases with hot glue. Have groups bring their models to the materials
table to use the glue gun so you can supervise the process.
C. Conclusion
As the teams in turn bring their models to the front of the room for
testing, test every model two ways—with the shaking table and by
applying weight. Tell students they are not allowed to touch their
structures during testing.
Ask two students from each team to hold the cardboard base down
while you test their model with weights. Use the strap to add hori-
zontal stress in any increment the group specifies. Call out the weights
and keep a record on the board of the greatest weight each structure
held. Award the certificate of achievement to the teams whose
structures withstand the shaking table and hold the greatest stress
before breaking. (This may be one team or two.)
Ask one member of each team to describe how their structure behaved
in testing. Where did it fail? Why?
Close by connecting the images students have of earthquake damage to
buildings with how their structures were damaged by the artificial
earthquakes of this event. Slides or videos would help to make this real.
ADA P T A T I ON S AND E X T E N S I ON S
1. After you have done this with one class and feel comfortable with
it, you may want to make the testing of student models a special event.
Create some award for the structure that carries the greatest shear
force. Invite your local newspaper reporters and school board
members, arrange to use the auditorium, tape appropriate music, and
plan refreshments. Take videos of the structure tests. Ask the principal
to apply the weights and judge the event, and invite local emergency
services officials to attend.
2. The experiences and materials the students developed in this unit
make a fine portfolio. Invite students to include drawings of their
designs and evaluate their learning by describing how they would build
a structure next time or how they would retrofit their structure.
V
all students have fun and are treated
equally.
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F E M A
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