Technological Impacts

1

DRILL

• What is structural technology?
• What comes to mind when you hear the word
  structure?

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CORE TECHNOLOGIES
Structural Technology

• The technology of putting mechanical parts and
  materials together to create supports,
  containers, shelters, connectors, and functional
  shapes.

• Example applications
• Legs on a chair,
• City water tower,
• Swimming pool,
• Roadways and Bridges,
• Bicycle spokes
• Airplane wing,
• Satellite antenna disc.

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UNIT 3 Engineering Design

• Engineering, the systematic application of
  mathematical, scientific, and technical
  principles, produces tangible end products that
  meet our needs and desires.

BIG IDEA
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Structural Technology

• PURPOSE OF SUB-UNIT

• To familiarize students with the functioning and
  applications of structural technology systems.

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Technology
What is technology? The application of
knowledge, tools, and skills to solve problems
and extend human capabilities. What is a
technology system? A Technology System is a
group of subsystems working together to solve
problems and extend human capabilities.
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Structural Technology
Structural engineers are responsible for
structural integrity.

• Structural failures do not occur very often, but
  when they do, we hear about it
• Tacoma Narrows bridge (1940)
• Challenger Space Shuttle (1986)
• Columbia Space Shuttle (2003)
• Chernobyl Nuclear Reactor (1986)
• 2007 Missouri bridge collapse
• As late as 1870s and 1880s, 25 bridges a year
  collapsed on the American roadways.
• Many people can be killed when engineered
  structures fail.

7
Structural Technology
Almost everything is a structure of some kind
Humans Plants Animals Houses Vehicles Tables Bottl
es
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The First Modern Engineer

• Galileo Galilei (1564 1642)
• The Father of Modern Physics
• The Father of Modern Science
• Research into the strengths of materials
• Prior to Galileo, the size and shape of most
  structures was determined by the traditions and
  rules of highly skilled craftsmen.

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Structural Technology

• Structural designs advanced by trial and error
  until modern engineers were able to anticipate
  the characteristics of new buildings, bridges,
  and other structures.
• Engineers apply science and mathematics to the
  problem of designing safe structures.
• Many engineering principles are based on common
  sense.

10
Structural Technology

• Newtons 3 Laws of Motion
• Inertia objects at rest stay at rest
• objects in motion stay in
  motion
• F ma
• Action/Reaction for every action there is an
  equal and opposite reaction

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Structural Technology

• Another way to look at it
• How much do you weigh?
• You are pushing down on the earth that amount of
  force.
• The earth is pushing up on you with an equal
  amount.
• What would happen if the earth were pushing up
  with more force?
• Less force?

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Strength of Materials

• Strength of a construction material is the
  capacity to support loads by resisting the 4
  structural forces.
• Strength depends on materials
• Type
• Size
• Shape
• Placement

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Structural Forces

• Four types of force exert stress on building
  materials
• Compression push tends to flatten/buckle
• Tension pull tends to stretch
• Shear slide material fractures
• Torsion twist twist out of shape or fracture

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Structural Forces
Tension
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Structural Forces
Compression
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Structural Forces
Torsion
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Structural Forces
Shear
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Structural Forces
Compression
Tension
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Strength of Materials

• Is bending one of the structural forces?
• Deflection bending that results from both
  tension and compression acting on a member at the
  same time.
• Vertical
• Horizontal

COMPRESSION
TENSION
COMPRESSION
TENSION
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Strength of Materials

• No deflection

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Structural Forces

• A structure must contend with two types of
  loads
• Dead Loads permanent loads that do not change.
• The weight of building materials and
  permanently installed components
• Lumber, brick, glass, nails, steel beams,
  concrete
• Live Loads the weight of all moveable objects,
  such as people and furniture in a house, vehicles
  on a bridge.
• Includes weight of snow, ice, dead leaves, and
  force of winds.

The total weight or mass of all live and dead
loads is the Total Load.
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Structural Forces

• A building supports the following loads in the
  middle of winter
• 10,000 lbs of lumber
• 1000 lbs. of snow and ice
• 40,000 lbs of brick
• 300 lbs of wind
• 600 lbs of glass
• 200 lbs of nails
• Calculate the Live Load.
• Calculate the Dead Load.

Live Load 1000 lbs. 300
lbs. 1,300 lbs.
Dead Load 10,000 lbs. 40,000
lbs. 600 lbs. 200 lbs.
50,800 lbs.
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Structural Forces

• Live Load 1,300 lbs.
• Dead Load 50,800 lbs.
• Calculate the Total Load
• Total Load Live Dead Load
• 1,300 lbs. 50,800 lbs.
• Total Load 52,100 lbs.

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Research Project

• Select one engineering structural failure.
• For that failure address the following
• Where the structure was built
• Purpose of the structure
• How the structure failed
• Who was responsible for the construction of the
  structure
• Who took the blame for the failure
• How many people were injured or killed

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HOMEWORK

1. Work on your Research Project
2. Rough draft sketch of poster and information due
   Tuesday!!