Materials Needed:
- 2 - 1" dia dowels or sticks
- Sheet of ordinary paper
- Sheet of ordinary cardboard (1/16" thick)
- Sheet of corrugated cardboard
- Sheet of Foamcore board
- Plastic sheets
- Small weights (up to 1lb)
Procedure: (see Figure 8)
- Place the dowels about 6" to 8" apart.
- Place the various materials across the dowels and
place weights at various positions.
- What positions do the weights have the least
effect on the shape of the material?
- Try two thicknesses of the same material and repeat
the application of weights.
- Is the extra strength worth the added weight to you?
Can you combine materials to achieve the
desired performance?
- Vary the shapes of the materials by folding into
a U or a fan (keep the size and weight of the
material constant) and repeat the application
of weights.
- What effect does folding have? Does direction
matter?
- Try the corrugated cardboard with ribs running across
and with the dowels.
- Why is corrugated cardboard used more frequently
for things than the same thickness of simple
cardboard?
Heavy paper can also be used and shapes can be produced using
scissors, tape and/or glue.
Figure 8: Stiffness investigation setup
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Observations:
The dowels or sticks represent your axles and wheels and they
allow the materials to flex and bend much as real wheels and
axles do with the chasses of the car. The differences in the
loads that a miniature car frame can carry with materials
of different strength and shape are demonstrated here. Use
this type of test to evaluate the materials you are considering
in the design of your car.
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