FUTURA – Week 7
Principles of Structures – Week 1
Agenda
Renzulli: Building Big due 10/27
 Donations:
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Straws – non flexible and LOTS! 
Newspaper – TONS! 
Paper Towel Tubes
Shoeboxes
Mini Marshmallows
Principles of Structures
Bill Nye: Structures
 Brain Pop - Building Basics
 Building Big - The Interactive Labs
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Basic Vocabulary of Structural Principles
Weight
 Support
 Load
 Span
 Thrust
 Stress
 Tension
 Compression
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Gravity
The pull of the earth that makes objects
feel heavy; most easily felt as a downward
force.
 Newton's Laws of Motion
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Forces
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Brain Pop – Force
You Tube - Structures & Forces
Tension – Stretching: lengthens the material
Compression – Squeezing: shortens the
material
Torque - Twisting
Shear - sliding
Center of Mass
Stability
Channeling Loads
Dead Loads
 Live Loads
 Dynamic Loads
 Wind Loads
 Earthquake Loads
 Thermal Loads
 Settlement Loads
 You Tube - Wind Loads on Structures
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Materials
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Elasticity
◦ a material whose change in shape vanishes rapidly when the loads on it disappear (rubber
band)
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Plasticity – able to be easily shaped or molded
Safety Factors
Steel
◦ Pound per pound, steel is the material with the greatest strength obtainable at the lowest
price.
◦ An alloy of iron and carbon
◦ Stainless Steel: add nickle
◦ Wrought Iron: less carbon (workable at low temperature)
◦ Cast Iron: high carbon (easily melted, cast into shapes)
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Reinforced Concrete
◦ Possibly the most interesting man-made structural material
◦ Formed into any shape, economical, available, fire resistant,
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Plastics
◦ Practically indestructible
◦ Fiberglas: reinforced with glass fibers making it shatterproof, strong in tension
Column
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A vertical (upright) support member.
Arch
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A true arch is a curving
structure that can span an
opening in a wall. It is
made from wedge-shaped
pieces that lean against
each other (in
compression). The central
piece is often larger than
the others. It is called the
keystone, and it is the last
piece to be put into place.
Post & Lintel
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Some of the earliest
builders used the postand-lintel principle of
construction to span
openings in a wall (doors
and windows). Before the
invention of the arch, they
used two vertical beams
(posts) to support the
horizontal beam (lintel).
Vault - Tunnel
A vault - is a tunnel in
the shape of a half
circle.
 Many animals burrow
tunnels underground.
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Dome
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A three dimensional form based on a
circle. A dome may be half a sphere, but
can take many other shapes. A dome is
a series of equal arches that span the
circle and meet in the center. These
arches are called the ribs, just like the
bones in your chest cavity that support
your upper body, give shape to your
torsos, and protect your lungs.
The top of a dome is in compression,
and gets stronger under a load because
the ribs are pressed against each other.
The bottom of the dome is in tension,
because the ribs want to push away
from each other. The bottom ring will
prevent this.
An egg shell is two domes put together.
Egg shells are suprisingly strong.
Column & Beam
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A beam is a horizontal structural member
supported by one, two, or more columns.
It is part of the skeleton of a building.
Cantilever
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A beam that is only supported at one
end.
Buttresses
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A buttress is a thickening in a
wall to make it stronger, or
small outside walls at right
angles acting to counteract the
outward thrust of a heavy roof
or wall.
A flying buttress is a buttress
with the non-structural part
removed, giving a feeling of
lightness. Gothic cathedrals
relied heavily on flying
buttresses.
Tension & Compression
Triangulation & Truss
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A truss is a system of support
members that are held rigid
(will not tend to collapse with
the edition of a load). Trusses
tend to be a series of triangles
and can be found in bridges,
pylons for electrical cables, or
the Eiffel Tower.
Acting out Structures
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Column
Arch
Post & Lintel
Vault-Tunnel
Dome
Column & Beam
Cantilever
Flying Buttresses
Load & Support
Tension
Compression
DESIGN PROCESS
IF AT FIRST…
…you don’t succeed,
try, try again. This
saying is at the heart
of the design process.
Testing a design and
then revising it based
on what you’ve
learned is an
important key to
success.
Design Process
When engineers solve a problem, their
first solution is rarely their best. Instead,
they try different ideas, learn from their
mistakes, and try again. The series of steps
engineers use to arrive at a solution is
called the design process.
 This is when your background knowledge,
along with creativity and originality come
into play.
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Design Process - Brainstorm
At this state, all ideas are welcome, and
criticism is not allowed. How creative can
you be?
 What specific goal are you trying to
achieve, and how will you know if you
have been successful?
 What are some ways you can start
tackling today’s challenge?
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Design Process - Designing
Time to get realistic. Talk through the
brainstormed ideas. What’s really possible
given your time, tools, and materials?
 It’s not cheating to look at other kids’
projects. What can you learn by looking at
them?
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Design Process – Building, testing,
evaluating, and revising
Does your design meet the criteria for
success?
 What is the hardest problem to solve as
you build your project?
 Why do you have to do something a few
times before it works the way you want?
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Design Process – Sharing solutions
What do you think is the best feature of
your design? Why?
 What are some things everyone’s designs
have in common?
 What would you do differently if you had
more time?
 What were the different steps you had to
do to get your project to work the way
you wanted?
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Logic – Teambuilding
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Collaborating – list to all ideas and contribute ideas of
your own
Critical Thinking – analyze the situation carefully
Problem Solving – work through the design process
toward a solution…you may fail along the way and that
is ok
Creative Thinking – think of new ideas based on what
you know
Communication – verbal with your group and written
on your planning sheet
Time Management – focus, stay on task, commitment
Self Assessing – you will assess yourself and your group
at the end.
Paper Table Challenge
Paper Table Challenge
 Teacher will put you into groups of 2 or 3
 DO NOT rush to the next step of the
design process…take your time and
THINK!
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Identify the Problem
Design and build a table out of newspaper
tubes. Make it at least 8 inches tall and
strong enough to hold a heavy book.
 Materials
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◦ 1 piece of cardboard (approximately 8.5 x 11
in)
◦ Heavy book (dictionary)
◦ Masking tape
◦ 8 Sheets of newspaper
Brainstorm & Design
Look at materials and think about the
questions below. Then sketch your ideas on a
piece of paper.
1. How can you make a strong tube out of a
piece of paper?
2. How can you arrange the tubes to make a
strong, stable table?
3. How can you support the table legs to keep
them from tilting or twisting?
4. How level and big does the table’s top need
to be to support a heavy book?
Build, Test, Evaluate, & Redesign
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Use the materials to build your table.
Then test it by carefully setting a heavy
book on it. When you test, your design
may not work as planned. If things don’t
work out, it’s an opportunity-not a
mistake! When engineers solve a problem,
they try different ideas, learn from
mistakes, and try again. Study the
problems and then redesign.
Build, Test, Evaluate, & Redesign
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For example, if:
◦ The tubes start to unroll – re-roll them so they are tighter. A tube
shape lets the load (i.e. the book) push on every part of the paper,
not just one section of it. Whether they’re building tables, buildings,
or bridges, load distribution is a feature engineers think carefully
about.
◦ The legs tilt or twist – Find a way to stabilize and support them.
Also check if the table is lopsided, too high, or has legs that are
damaged or not well braced.
◦ A tube buckles when you add weight – Support or reinforce the
weak area, use a wider or thicker walled tube, or replace the tube
if it’s badly damaged. Changing the shape of a material affects its
strength. Shapes that spread a load well are strong. Dents, creases,
and wrinkles that put stress on some areas more than others
make a material weaker.
◦ The table collapses – Make its base as sturdy as possible. Also, a
table with a lot of triangular supports tends to be quite strong. A
truss is a large, strong support beam. It is built from short boards
or metal rods that are arranged as a series of triangles. Engineers
often use trusses in bridges, buildings, and towers.
Design Process – Sharing solutions
What do you think is the best feature of
your design? Why?
 What are some things everyone’s designs
have in common?
 What would you do differently if you had
more time?
 What were the different steps you had to
do to get your project to work the way
you wanted?
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Centers
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Level Contract: Complete all activities in that level first
Activities
◦ Thinker
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Problem Solve
Think Critically
Be Creative
Research: use Renzulli or Online Databases (safety) and log
resources!
◦ Worker
 Pursue Challenge
 Manage Time
 Produce Quality Work
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Reflection Assessment
◦ Reflector
 Self-Assessing Product and Performance