225f0dcdc64529779172d0e96716ca39.ppt

- Количество слайдов: 66

+ TISP: What is available to teachers and students July 2009 Selected Lesson Plans from the TISP Library

+ TISP: Shenzhen July 2009 Moshe Kam D. G. Gorham Ship the Chip Sort It Out Critical Load Pulleys and Force Rotational Equilibrium Understanding Bar Codes

+ Exercise 1: Ship The Chip Package design and the engineering behind shipping products safely

+ 4 Ship the Chip Objectives n Learn about engineering product planning and design n Learn about meeting the needs of the customer and society n Learn about teamwork and cooperation

+ 5 Ship the Chip Students will learn… n Manufacturing n Package Engineering design, manufacture and test n Material properties and selection n Real world application of mathematics n Teamwork

+ 6 Ship the Chip The Challenge n. Design a package that will securely hold a potato chip and protect it from breaking when dropped n. Construct the lightest package to get the highest score n Overall n Weight score based on: of the package n Volume of the package n Intactness Score

+ 7 Ship the Chip Procedure Sketch a design on the worksheet 1. n 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 n 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 Ship the Chip Materials n Cardboard n 10 n 6 – 22 cm x 28 cm Craft sticks Cotton Balls n String – 91 cm n Plastic n 10 wrap – 1 sheet of 22 cm x 28 cm Toothpicks n Foil – 1 sheet of 22 cm x 28 cm n Paper – 1 sheet of 22 cm x 28 cm n 1 Mailing label n 1 Potato Chip

+ 9 Ship the Chip Tools and Accessories n Scissors n Pencils/Pens n Rulers n Digital Scale n Marking pen n Calculator n Clear Tape Adhesive n Masking Tape

+ 10 Ship the Chip Scoring Intactness score : n 100: like new, perfect n 50 : slightly damaged; cracked but still in one piece n 25 : broken in 2 - 5 pieces n 5 : broken in 6 -20 pieces n 1 : broken into more than 20 pieces; crumbled

+ Ship the Chip Calculating Volume n We will imbed the package in the smallest-volume rectangular prism that contains it n We will calculate the volume of the prism; n n n Width x Length x Height For example : 3 cm x 4 cm x 12 cm =144 cm 3 in the prism shown below If your package weighed 100 g and had a volume of 800 cm 3 and the chip has arrived broken in 3 pieces: 11

+ Ship the Chip Procedure Sketch a design on the worksheet 1. n 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 n 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 12

+ Exercise 2: Sort It Out! The engineering behind industrial sorting processes

+ 14 Sort It Out Objectives Learn about engineering of systems and about measurements n n Learn about sorting mechanisms n. Get an introduction to Performance Indices and measures of errors Learn about teamwork and cooperation n

+ 15 Sort It Out Sorting through History n Miners panning for gold n Quality control in food and other industries n Bottle sorting for recycling

+ 16 Sort It Out Different Types of Sorting n Image Processing for the operation of Casinos n Off-the-shelf cameras, frame grabbers, and imageprocessing software used to develop a casino-coin sorting. Lighting system Frame Grabber Digital I/O & Network Connection Camera & Optics PC platform Inspection software Part Sensor

+ 17 Sort It Out Different Types of Sorting n Material Properties of Coin: n Current run through left coil, creates magnetic field n Magnetic field passes through and is attenuated by coin n Right coil receives magnetic field, creates measurable current with different value depending Coin in Center Transverse line represents direction of magnetic field

+ 18 Sort It Out Why Coin Sorting is Needed n Mixed coins come from a variety of sources and must be sorted out before they can be redistributed n Coins from vending machines n Coins from parking meters n Also helpful to identify fake or foreign coins

+ 19 Sort It Out Why Coin Sorting is Needed n Mixed coins are n Sorted n Rolled n Re-circulated through banks and businesses

+ 20 Sort It Out Your Turn n Groups of 2 n You are a team of engineers hired by a bank to develop a machine to sort coins that are brought in by customers. n Must mechanically sort 16 mixed coins into separate containers. n In our experiment we use washers: n ½ Inch You will make TWO n 1 Inch designs today n 1¼ Inch n 1½ Inch

+ 21 Sort It Out! Parallel Sorter Input Sorting Mechanism ½” 1” 1½” 1¼” Output

+ 22 Sort It Out! Parallel Sorter Input Sorting Mechanism ½” 1½” 1¼” Output

+ 23 Sort It Out! Serial Sorter Input Sorting Mechanism ½” 1½” 1¼” Output

+ 24 Sort It Out Performance Index 1: “Distance Index” How good is it? n 1: “Distance” performance index: ½ ½½ ½ 1 ½in ½ 1 1 1 in 1 1¼ 1¼ 1¼in 1 1½ 1½ 1½in Distance from correct bin here, Derror = 2 bins n. A washer that does not get sorted has maximum Derror = 3

+ 25 Sort It Out Performance Index 2: “Percentage Index” How good is it? n 2: “Percentage” performance index: ½ ½½ ½ 1 ½in ½ 1 1 1¼ 1¼ 1¼ 1 in 1¼in 1 1½ 1½ 1½in # of washers incorrectly identified Total # of washers to sort 40 5%

Sort It Out! Table Number: Type of Sorter Serial Team Name: Parallel # of this type in Container for this size washer: each container 1/2" 1" 1 1/4" Total washers sorted: 16 1 1/2": Number left unsorted: 1": Distance Index: 1 1/4": 1 1/2": Percentage Index:

Sort It Out! 16 Table Number: Team Name: Type of Sorter The Perfect Group Serial Parallel Total washers sorted: 16 # of this type in Container for this size washer: each container 1/2" 1" 1 1/4" 1 1/2" 4 Number left unsorted: 0 1": 4 Distance Index: 1 1/4": 4 1 1/2": 4 Percentage Index: 0% 1/2": 0

Sort It Out! n Distance Performance Index n sqrt( 0 x 12 + 0 x 22 + 0 x 32 ) = 0 n A Perfect Score! n Remember: Lower is better n Percentage n( Performance Index 0 / 16 ) x 100 = 0% n Another Perfect Score!

Sort It Out! 16 Table Number: Team Name: Type of Sorter Not That Perfect Serial Parallel Total washers sorted: 16 # of this type in Container for this size washer: each container 1/2" 1" 1 1/4" 1 1/2" 4 Number left unsorted: 0 1": 4 Distance Index: 1 1/4": 4 1 1/2": 1 3 Percentage Index: 6. 25% 1/2": 1

Sort It Out! n Distance Performance Index n sqrt( 1 x 12 + 0 x 22 + 0 x 32 ) = 1 n A Less Than Perfect Score! n Remember: Lower is better n Percentage n( Performance Index 1 / 16 ) x 100 = 6. 25% n A Less Than Perfect Score!

Sort It Out! 16 Table Number: Team Name: Type of Sorter The Truly Miserable Serial Parallel Total washers sorted: 16 # of this type in Container for this size washer: each container 1/2" 1" 1 1/4" 1 1/2" 1 1 1 1 4 Distance Index: 1 1/4": 4 1 1/2": 2 1/2": 1": Number left unsorted: 2 6. 16 Percentage Index: 56%

Sort It Out! 1/2": 1 1/4": 1 1/2": n Distance 1 4 1 4 1 1 Number left unsorted: 2 Distance Index: 2 Percentage Index: 6. 16 56% Performance Index n sqrt( 1 x 12 + 1 x 22 + 4 x 22 + 1 x 32 + 2 x 32) = 6. 16 n Much higher score, much lower performance n Remember: Lower is better n Percentage n( Performance Index 9 / 16 ) x 100 = 56. 25% n Again, much lower performance

+ 33 Sort It Out Your Turn n Mechanical “shaking” of your device is allowed as part of its operation Design (draw) a mechanical sorter that can separate the ½in, 1¼in, 1½in washers n Input: either n Parallel – all 16 washers are inserted at start of your sorter together; or n Serial – 16 washers are inserted at start of your sorter one at a time n Output: Each size of washer in its own physical container or surface n Materials: n glue, tape, paper or plastic plates, cardboard, scissors or hole punch, foil, paper, cardboard tubes n washers

+ 34 Sort It Out Your Turn n You will have 45 seconds to allow your sorter to operate n Predict the value of the two performance indices for your design n Construct your sorting mechanism n Test it! n Can you do better? You will make TWO designs today: one PARALLEL and one SERIAL Mechanical “shaking” of your device is allowed as part of its operation

+ 35 Sort It Out Conclusion n Did your sorting mechanism work? If not, why did it fail? n What were your performance index values? n What levels of error would be acceptable in: n n Medical Equipment manufacturing? Nail manufacturing? n What redesigns were necessary when you went to construct your design? Why?

+ Exercise 3: Pulleys & Force All about force and how pulleys can help reduce it

+ 37 Pulleys & Force Objectives n Learn about pulleys and pulley systems n Learn how using multiple pulleys can dramatically reduce required force n Learn how pulley systems are used in machines and impact everyday life n Learn about teamwork and problem solving in groups

+ 38 Pulleys & Force Basics of Pulleys: Two orientations Fixed Pulley Movable Pulley

+ The tension in the rope, T, is always the same everywhere n Pulleys & Force n Fixed pulley allows for change in direction of applied force n Sum of the forces: vertically Basics of Pulleys Compound Pulley 2 T = 100 N T = 50 N 39

+ 40 Pulleys & Force Mechanical Advantage n Mechanical Advantage (MA) is the factor by which a mechanism multiplies the force or torque put into it. n Ideal MA: n Actual MA: This movable pulley system has a mechanical advantage of 2

+ 41 Pulleys & Force Work n Work is the amount of energy transferred by a force acting through a distance n Work = Force x Distance n A bigger mechanical advantage decreases the force required, but increases the distance over which it must be applied n The total amount of work required to move the load stays the same

+ 42 Pulleys & Force Efficiency n The ratio between Actual and Ideal mechanical advantage is Efficiency n Frictionless system = 100% Efficiency

+ 43 Pulleys & Force Pulleys in the World n Pulleys have long been used on sailing ships to handle the rigging and move the sails n Even with large mechanical advantages, it still takes many people to do the work!

+ 44 Pulleys & Force Pulleys in the World n Pulleys are used in elevators to change the direction of the tension in the cable, reduce power required of lift motor

+ 45 Pulleys & Force Pulleys in the World n Industrial cranes lift large loads for construction and transportation

+ 46 Pulleys & Force Measuring Tension n Spring Scale n Calibrate: Hold spring scale at eye-level and turn adjustment screw until the internal indicator is precisely aligned with the top zero line n 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.

+ Pulleys & Force Your Turn n Groups of 2 n Develop 2 systems to lift a filled soda bottle 10 cm with n 1 pulley n 2 pulleys n Build your systems n Measure the distance the soda bottle moves and compare it to the distance you had to pull n n Measure the force you must exert on the string and compare it to the force that is finally transmitted to the soda bottle n n What is the actual mechanical advantage? What is the ideal mechanical advantage? Calculate the efficiency of each system 47

+ 48 Pulleys & Force Your Turn n Now join with one other group at your table n Develop 2 different systems to lift a filled soda bottle 10 cm with all 4 pulleys n Build both systems n What are their actual mechanical advantages? Ideal? n Which one has a better efficiency? Why do think that is?

+ 49 Pulleys & Force Conclusion n Which system required the least amount of force to lift the bottle? How did this system rank in its mechanical advantage? n Do you think the size of the pulley makes a difference in the ideal mechanical advantage? Actual? n How could you further increase the efficiency of your most efficient pulley system design? n What other engineering problems were solved with pulleys or pulley systems?

+ 50 Spring Scale n www. arborsci. com

+ Exercise 4: Critical Load Structural engineering and how to reinforce the design of a structure to hold more weight.

+ 52 Critical Load Objectives n Learn about civil engineering and the testing of building structure n Learn about efficiency ratings and critical load n Learn about teamwork and the engineering problem solving

+ 53 Critical Load Great Structures of the World Millau Viaduct n Millau, France n World’s Tallest Bridge n 2460 m long 434 m pylon height 270 m road height n December, 2004

+ 54 Critical Load Great Structures of the World Yokohama Landmark Tower n Yokohama, Japan n Japan’s Tallest Office Building n 296 m tall 70 floors including office and hotel n July, 1993

+ 55 Critical Load Great Structures of the World Beijing National Stadium – “Bird’s Nest” n n n World’s Largest Steel Structure 258, 000 square meters 5 years to construct n 110, 000 tons of steel used in construction n 3, 000 cubic meters n Opened June, 2008

+ 56 Critical Load Great Structures of the World Crystal Cathedral n Garden Grove, California, USA n World’s Largest Glass Building n 12 stories tall 12, 000+ panes of glass n 16, 000 -pipe organ n Opened 1980

+ 57 Critical Load Great Card Structures of the World Skyscraper of Cards n 2007 World Record House of Cards n Over 7. 5 meters tall n No glue or tape; just cards n Built 2007 by Bryan Berg in

+ 58 Bryan Berg at Work A “cardstacker” from Santa Fe, NM, USA

+ 59 Critical Load What is Critical Load? n Force is placed on a structure Force n Structure can support up to a certain force created by the weight n At a certain point, the structure will fail, breaking n The maximum force the structure can sustain before failure is known as the “Critical Load” Force

+ 60 Critical Load Efficiency n. A high critical load is not the only parameter to consider n Is the best bridge made by filling a canyon with concrete? It certainly would have a high critical load! n Consider n also the weight of the structure Lighter is better, given the same critical load n These two parameters are combined in an “Efficiency Rating”:

+ 61 Critical Load Your Turn n Groups of 2 n Up to 12 cards + 1 m tape n Devise a plan to build a load bearing structure n Should have a flat top n Support load with base area of 10 x 10 cm at least 8 cm above the table n No altering of cards allowed – just tape! n No wrap-ups of tape n Tape is used to connect cards only

+ FREQUENTLY ASKED QUESTIONS n STRUCTURE NEEDS TO BE CONNECTED n BENDING OF CARDS IS ALLOWED n CUTTING OF CARDS IS NOT ALLWOED n YOU CAN ATTACH SEVERAL CARDS TOGETHER TO MAKE A THICKER CARD n THE TOP OF THE STRUCTURE SHOULD ALLOW FOR A LOAD WITH 10 X 10 CM BASE n HEIGHT SHOULD BE AT LEAST 8 CM 62

+ 63 Critical Load Your Turn n Example: n Supports load n Load is at least 8 cm above table n Cards failed after load of 2. 4 kg n Structure made with 4 cards n Efficiency rating: 2. 4 kg / 4 cards = 0. 6 kg/card 8. 5 cm height

+ 64 Critical Load Your Turn n Your efficiency rating: [Load at Failure] / [# of cards used] n Predict n Build n Test what the rating of your design will be your design it! n Discuss improvements, then repeat exercise for a second design

+ 65 Critical Load Conclusion n What was your efficiency rating? How close were you to your prediction? n How was your design different from the best design? n How would you change your design? Why? n What other factors would you need to take into consideration if your Card House were a real office building?

+ The End Questions or Comments 66