spaghetti and glue as building materials -...
TRANSCRIPT
Spaghetti and Glue as Building
Materials
David Dobson, Electrical Engineer, USQ
graduate and 3rd place in the 2013 Thiess
Spaghetti Bridge Competition, RME
How Spaghetti was chosen
• Purchased all available
spaghetti- differing
brands and sizes
• Stress test
– Horizontal load
– Vertical load
• Compression
• Tension
• Weight held ---------------
-------- Weight of 10
strands (equal length)
Choice of Glue
• PVA
– Slow drying
– Strong bond
– Fill voids
• Hot Glue
– Fast drying
– Weak bond
– Fill voids
• Superglue
– Fast setting
– Strong bond-low shear
– No voids
Necessary to build a prototype?
• YES
• Partial build of main
features
• Test out Glue
• Test out spaghetti
choices
Management of brittleness
• Design
• Tried to reduce amount
of tension
– More spaghetti under
tension than
compression
– Shared between more
strands
• Keep straight
– Direct forces
– Reduce/remove bending
forces (shear?)
• Shorter multiple pieces
under tension
Spaghetti inspection
• Flaws or imperfections
in spaghetti
– Cracking
• Longitudinal
• Lateral
– Necking- Narrowing
– Curvature
– Discolouration
– Contaminates
• Is derived from raw
materials – expect
contaminates.
Troubleshooting
• Spaghetti shrinks when
dried.
• Don’t let dry unevenly
• Use spaghetti from
same packet
• Store spaghetti with
bridge
• Atmospheric conditions
make a difference
What to do with excess spaghetti?
David Dobson
References
• http://pages.jh.edu/~virtlab/bridge/truss.htm
• http://jeramypaxton.com/2013/05/project-rc-kite-initial-testing/
• http://www.lloyd-instruments.co.uk/Accessories/Food-
texture/Pasta-Rice.aspx
• http://en.wikipedia.org/wiki/Cyanoacrylate
• http://ilovebacteria.com/spaghetti.htm
• http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.95.09
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