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+ WELCOME! TISP: Uruguay 9–10 May 2009
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+ WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Apr 01, 2015

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Page 1: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

WELCOME!

TISP: Uruguay

9–10 May 2009

Page 2: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Sort It Out Critical LoadPulleys and ForceShip the Chip

Christopher Lester

Yvonne PelhamMoshe Kam

D.G. Gorham

TISP: Uruguay

9–10 May 2009

Page 3: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Welcome

3

Page 4: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Package design and the engineering behind shipping products safely

Exercise 1:

Ship The Chip

Page 5: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

Learn about engineering product planning and design

Learn about meeting the needs of the customer and society

Learn about teamwork and cooperation

Objectives

5

Page 6: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

Manufacturing EngineeringPackage design, manufacture and test

Material properties and selection

Real world application of mathematics

Teamwork

6

Students will learn…

Page 7: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

Design a package that will securely hold a potato chip and protect it from breaking when dropped

Construct the lightest package to get the highest score Overall score based on:

Weight of the package Volume of the package Intactness Score

7

The Challenge

Page 8: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

1. Sketch a design on the worksheet Label your worksheet with Table # and Team Name

2. Construct a model of your package

3. At a test station, drop the package from a height of 1.5 meters

4. Open your package and examine the chip

5. Calculate and record your score

6. Using a second kit, redesign and construct a new package Record the second design on the worksheet

7. Label your package with Table # and Team Name

8. Submit your worksheet and package to the Test Team for overnight testing

8

Procedure

Page 9: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

Cardboard – 22 cm x 28 cm 10 Craft sticks 6 Cotton Balls String – 91 cm Plastic wrap – 1 sheet of 22 cm x 28 cm 10 Toothpicks Foil – 1 sheet of 22 cm x 28 cm Paper – 1 sheet of 22 cm x 28 cm 1 Mailing label 1 Potato Chip

9

Materials

Page 10: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

10

Tools and Accessories

Page 11: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Intactness score :

100: like new, perfect

50 : slightly damaged; cracked but still in one piece

25 : broken in 2 - 5 pieces

5 : broken in 6-20 pieces

1 : broken into more than 20 pieces; crumbled

11

Ship the ChipScoring

3

__

_ _ _ _

Intactness ScoreOverall Score

Weight in Kg Volume in cm

Page 12: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

We will imbed the package in the smallest-volume rectangular prism that contains it

We will calculate the volume of the prism; Width x Length x Height For example : 3cm x 4cm x12cm =144 cm3 in the prism

shown below

If your package weighed 100g and had a volume of 800 cm3 and the chip has arrived broken in 3 pieces:

12

Calculating Volume

3

__

_ _ _ _

Intactness ScoreOverall Score

Weight in Kg Volume in cm

25_ 0.3125

0.1 800Overall Score

Page 13: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Ship the Chip

1. Sketch a design on the worksheet Label your worksheet with Table # and Team Name

2. Construct a model of your package

3. At a test station, drop the package from a height of 1.5 meters

4. Open your package and examine the chip

5. Calculate and record your score

6. Using a second kit, redesign and construct a new package Record the second design on the worksheet

7. Label your package with Table # and Team Name

8. Submit your worksheet and package to the Test Team for overnight testing

13

Procedure

Page 14: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

The engineering behind industrial sorting processes

Exercise 2:

Sort It Out!

Page 15: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Safety First!!

This experiment uses scissors and box cutters!

Please be slow, concentrated, and careful when using them

15

Page 16: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out

Learn about engineering of systems and about measurements

Learn about sorting mechanisms

Get an introduction to Performance Indices and measures of errors

Learn about teamwork and cooperation

Objectives

16

Page 17: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It OutSorting through History

Miners panning for gold

Quality control in food and other industries

Bottle sorting for recycling

17

Page 18: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It OutDifferent Types of Sorting

Lighting

Digital I/O & Network

ConnectionFrame

Grabber

Part Sensor

Camera &

PC platform

Inspection software

Optics

Image Processing for the operation of Casinos:

Off-the-shelf cameras, frame grabbers, and image-processing software used to develop a casino-coin sorting system

18

Page 19: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It OutDifferent Types of Sorting

Material Properties of Coin: Current run through left

coil, creates magnetic field Magnetic field passes

through and is attenuated by coin

Right coil receives magnetic field, creates measurable current with different value depending on the coin

Coin in Center

Transverse line represents direction of magnetic field

19

Page 20: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Mixed coins come from a variety of sources and must be sorted out before they can be redistributed Coins from vending

machines Coins from parking meters

Also helpful to identify fake or foreign coins

Sort It OutWhy Coin Sorting is Needed

20

Page 21: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Mixed coins are Sorted Rolled Re-circulated

through banks and businesses

Sort It OutWhy Coin Sorting is Needed

21

Page 22: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Groups of 2

You are a team of engineers hired by a bank to develop a machine to sort coins that are brought in by customers.

Must mechanically sort 16 mixed coins into separate containers.

In our experiment we use washers: ½ Inch 1 Inch 1¼ Inch 1½ Inch

Sort It OutYour Turn

22

You will make TWO designs today

Page 23: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out!Parallel Sorter

23

Input

SortingMechanism

Output

½” ½” 1” 1”

1½” 1½” 1¼”1¼”

Page 24: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out!Parallel Sorter

24

Input

SortingMechanism

Output

Page 25: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out!Serial Sorter

25

Input

Output

SortingMechanism

Page 26: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out

How good is it?

1: “Distance” performance index:

A washer that does not get sorted has maximum Derror = 3

Performance Index 1: “Distance Index”

½in 1in 1¼in 1½in1

Distance from correct binhere, Derror = 2 bins

11

26

½

½

½

½

½

1½1¼11 1 1 1¼

1¼1¼

1¼ 1½

1½ 1½

Page 27: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out

How good is it?

2: “Percentage” performance index:

Performance Index 2: “Percentage Index”

27

½in 1in 1¼in 1½in1

11

½

½

½

½

½

1½1¼11 1 1 1¼

1¼1¼

1¼ 1½

1½ 1½

# of washers incorrectly identified

Total # of washers to sort 405%

Page 28: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Table Number:         Type of Sorter Serial

Team Name:           Parallel

# of this type in Container for this size washer:

Total washers sorted: 16

each container 1/2" 1" 1 1/4" 1 1/2"

1/2":         Number left unsorted:

1":         Distance Index:  

1 1/4":            

1 1/2":         Percentage Index:  

Page 29: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Table Number:    16     Type of Sorter Serial

Team Name:   The Perfect Group   Parallel

# of this type in Container for this size washer:

Total washers sorted: 16

each container 1/2" 1" 1 1/4" 1 1/2"

1/2":  4       Number left unsorted: 0

1":   4     Distance Index:  

1 1/4":      4      

1 1/2":       4  Percentage Index:  

0

0%

Page 30: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Distance Performance Index sqrt( 0x12 + 0x22 + 0x32 ) = 0 A Perfect Score!

Remember: Lower is better

Percentage Performance Index ( 0 / 16 ) x 100 = 0% Another Perfect Score!

Page 31: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Table Number:    16     Type of Sorter Serial

Team Name:   Not That Perfect   Parallel

# of this type in Container for this size washer:

Total washers sorted: 16

each container 1/2" 1" 1 1/4" 1 1/2"

1/2":  4       Number left unsorted: 0

1":   4     Distance Index:  

1 1/4":      4      

1 1/2":     1  3  Percentage Index:  

1

6.25%

Page 32: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Distance Performance Index sqrt( 1x12 + 0x22 + 0x32 ) = 1 A Less Than Perfect Score!

Remember: Lower is better

Percentage Performance Index ( 1 / 16 ) x 100 = 6.25% A Less Than Perfect Score!

Page 33: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Table Number:    16     Type of Sorter Serial

Team Name:   The Truly Miserable   Parallel

# of this type in Container for this size washer:

Total washers sorted: 16

each container 1/2" 1" 1 1/4" 1 1/2"

1/2":  1  1  1 1  Number left unsorted: 2

1":   4     Distance Index:  

1 1/4":  4          

1 1/2":       2  Percentage Index:  

6.16

56%

Page 34: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

Sort It Out!

Distance Performance Index sqrt( 1x12 + 1x22 + 4x22 + 1x32 + 2x32) = 6.16 Much higher score, much lower performance

Remember: Lower is better

Percentage Performance Index ( 9 / 16 ) x 100 = 56.25% Again, much lower performance

1/2":  1  1  1 1  Number left unsorted: 2

1":  4

   Distance Index:

6.16

1 1/4":  4 

     

1 1/2":   

  2 Percentage Index:

56%

Page 35: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Materials: glue, tape, paper or plastic

plates, cardboard, scissors or hole punch, foil, paper, cardboard tubes

washers

Design (draw) a mechanical sorter that can separate the ½in, 1in, 1¼in, 1½in washers

Input: either Parallel – all 16 washers

are inserted at start of your sorter together; or

Serial – 16 washers are inserted at start of your sorter one at a time

Output: Each size of washer in its own physical container or surface

Sort It OutYour Turn

35

Mechanical “shaking” of your device is allowed as part of its operation

Page 36: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out

You will have 45 seconds to allow your sorter to operate

Predict the value of the two performance indices for your design

Construct your sorting mechanism

Test it!

Can you do better?

Your Turn

36

Mechanical “shaking” of your device is allowed as part of its operation

You will make TWO designs today: one PARALLEL and one SERIAL

Page 37: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Sort It Out

Did your sorting mechanism work? If not, why did it fail?

What were your performance index values?

What levels of error would be acceptable in: Medical Equipment manufacturing? Nail manufacturing?

What redesigns were necessary when you went to construct your design? Why?

Conclusion

37

Page 38: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

All about force and how pulleys can help reduce it

Exercise 3:

Pulleys & Force

Page 39: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Pulleys & Force

Learn about pulleys and pulley systems

Learn how using multiple pulleys can dramatically reduce required force

Learn how pulley systems are used in machines and impact everyday life

Learn about teamwork and problem solving in groups

Objectives

39

Page 40: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+ 40

Fixed Pulley Movable Pulley

Pulleys & ForceBasics of Pulleys: Two orientations

Page 41: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+ The tension in the rope, T, is always the same everywhere

Fixed pulley allows for change in direction of applied force

Sum of the forces: vertically

2 T = 100 N T = 50 N

41

Compound Pulley

Pulleys & ForceBasics of Pulleys

Page 42: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Pulleys & ForceMechanical Advantage

Mechanical Advantage (MA) isthe factor by which a mechanism multiplies the force or torque put into it.

Ideal MA:

Actual MA:

42

This movable pulley system has a mechanical advantage of 2

Page 43: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Work is the amount of energy transferred by a force acting through a distance

Work = Force x Distance

Work = Force x Distance A bigger mechanical advantage

decreases the force required, but increases the distance over which it must be applied

The total amount of work required to move the load stays the same

43

Pulleys & ForceWork

Page 44: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

The ratio between Actual and Ideal mechanical advantage is Efficiency

Frictionless system = 100% Efficiency

44

Pulleys & ForceEfficiency

Page 45: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Pulleys have long been used on sailing ships to handle the rigging and move the sails

Even with large mechanical advantages, it still takes many people to do the work!

Pulleys & ForcePulleys in the World

45

Page 46: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Pulleys are used in elevators to change the direction of the tension in the cable, reduce power required of lift motor

Pulleys & ForcePulleys in the World

46

Page 47: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Industrial cranes lift large loads for construction and transportation

Pulleys & ForcePulleys in the World

47

Page 48: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Pulleys & ForceMeasuring Tension

Spring Scale

Calibrate: Hold spring scale at eye-level and turn adjustment screw until the internal indicator is precisely aligned with the top zero line

Measure: Create a loop in the end of the rope you want to measure tension in; attach spring scale to loop. Hold the spring scale steady and read off the tension measurement.

48

Page 49: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Groups of 2

Develop 2 systems to lift a filled soda bottle 10cm with

1 pulley

2 pulleys

Build your systems

Measure the distance the soda bottle moves and compare it to the distance you had to pull

What is the actual mechanical advantage?

Measure the force you must exert on the string and compare it to the force that is finally transmitted to the soda bottle

What is the ideal mechanical advantage?

Calculate the efficiency of each system

Pulleys & ForceYour Turn

49

Page 50: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Now join with one other group at your table

Develop 2 different systems to lift a filled soda bottle 10cm with all 4 pulleys

Build both systems

What are their actual mechanical advantages? Ideal?

Which one has a better efficiency? Why do think that is?

Pulleys & ForceYour Turn

50

Page 51: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Pulleys & Force

Which system required the least amount of force to lift the bottle? How did this system rank in its mechanical advantage?

Do you think the size of the pulley makes a difference in the ideal mechanical advantage? Actual?

How could you further increase the efficiency of your most efficient pulley system design?

What other engineering problems were solved with pulleys or pulley systems?

Conclusion

51

Page 52: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Spring Scale

www.arborsci.com

52

Page 53: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

End of Saturday Exercises

53

Page 54: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

TISP: UruguaySunday, 10 May 2009

54

Page 55: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Structural engineering and how to reinforce the design of a structure to hold more weight.

Exercise 4:

Critical Load

Page 56: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Critical Load

Learn about civil engineering and the testing of building structure

Learn about efficiency ratings and critical load

Learn about teamwork and the engineering problem solving

Objectives

56

Page 57: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Millau Viaduct

Millau, France

World’s Tallest Bridge

2460m long434m pylon height270m road height

December, 2004

Critical LoadGreat Structures of the World

57

Page 58: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Yokohama Landmark Tower

Yokohama, Japan

Japan’s TallestOffice Building

296m tall70 floors including office and hotel

July, 1993

Critical LoadGreat Structures of the World

58

Page 59: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Beijing National Stadium – “Bird’s Nest”

World’s Largest Steel Structure

258,000 square meters

5 years to construct

110,000 tons of steel used in construction

3,000,000 cubic meters

Opened June, 2008

Critical LoadGreat Structures of the World

59

Page 60: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Crystal Cathedral

Garden Grove,California, USA

World’s Largest Glass Building

12 stories tall12,000+ panes of glass

16,000-pipe organ

Opened 1980

Critical LoadGreat Structures of the World

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Page 61: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Skyscraper of Cards

2007 World RecordHouse of Cards

Over 7.5 meters tall

No glue or tape; just cards

Built by Bryan Berg in 2007

Critical LoadGreat Card Structures of the World

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Page 62: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Bryan Berg at WorkA “cardstacker” from Santa Fe, NM, USA

62

Page 63: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Force is placed on a structure

Structure can support up to a certain force created by the weight

At a certain point, the structure will fail, breaking

The maximum force the structure can sustain before failure is known as the “Critical Load”

Critical LoadWhat is Critical Load?

Force

Force

63

Page 64: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Critical Load

A high critical load is not the only parameter to consider Is the best bridge made by filling a canyon with

concrete? It certainly would have a high critical load!

Consider also the weight of the structure Lighter is better, given the same critical load

These two parameters are combined in an “Efficiency Rating”:

Efficiency

64

Page 65: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+

Groups of 2

Up to 12 cards + 1m tape

Devise a plan to build a load bearing structure Should have a flat top Support load with base area

of 10x10cm at least 8 cm above the table

No altering of cards allowed – just tape!

No wrap-ups of tape Tape is used to connect cards

only

Critical LoadYour Turn

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+FREQUENTLY ASKED QUESTIONS STRUCTURE NEEDS TO BE CONNECTED

BENDING OF CARDS IS ALLOWED

CUTTING OF CARDS IS NOT ALLWOED

YOU CAN ATTACH SEVERAL CARDS TOGETHER TO MAKE A THICKER CARD

THE TOP OF THE STRUCTURE SHOULD ALLOW FOR A LOAD WITH 10X10CM BASE

HEIGHT SHOULD BE AT LEAST 8CM

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+

Example: Supports load Load is at least 8cm

above table Cards failed after load

of 2.4kg Structure made with 4

cards Efficiency rating:

2.4 kg / 4 cards = 0.6 kg/card

Critical LoadYour Turn

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8.5 cmheight

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+Critical Load

Your efficiency rating:[Load at Failure] / [# of cards used]

Predict what the rating of your design will be

Build your design

Test it!

Discuss improvements, then repeat exercise for a second design

Your Turn

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Page 69: + WELCOME! TISP: Uruguay 9–10 May 2009. + Sort It Out Critical Load Pulleys and Force Ship the Chip Christopher Lester Yvonne Pelham Moshe Kam D.G. Gorham.

+Critical Load

What was your efficiency rating?How close were you to your prediction?

How was your design different from the best design?

How would you change your design? Why?

What other factors would you need to take into consideration if your Card House were a real office building?

Conclusion

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+

End of Sunday Exercises

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