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STEM Integration With Principles of Engineering. International Technology Education Association Thursday - March 18, 2010 Charlotte, N.C. Case Study: Auto Safety Presenters: Chuck Goodwin & Jan Stark. STE 2 M. E L A. STE 2 M. Principles of Engineering Developed Case Studies. Auto Safety
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STEM IntegrationWith Principles of Engineering International Technology Education Association Thursday - March 18, 2010 Charlotte, N.C. Case Study: Auto Safety Presenters: Chuck Goodwin & Jan Stark
STE2M E L A STE2M
Principles of EngineeringDeveloped Case Studies • Auto Safety • Structures - Survival Shelter • Energy - Solar Electric Vehicle Design & or Solar Efficient Home • Machine Automation and Control • Ergonomics & Communications Technology • Designing Technology For People with Disabilities
Role of the Teacher • Instructor - Facilitator - Task Master • Set Guidelines • Establish the Premise • Identify Constraints & Schedule • Guide Students Through Process • Research Expectations • Brainstorming • Team Structures and Dynamics • Journaling • Assign Knowledge Building Labs/Experiments • Ongoing Assessments - Scoring Rubrics • Student Developed Tests of Design Features • Final Test of Vehicle Performance - Analysis of outcomes • Oral Presentation of Team Findings and Related Data.
Automobile Design Variables • Vehicle Weight • Engine / Power plant Type • Aerodynamics • Cargo Capacity • Passenger Capacity • Fuel Economy • Ease of Maintenance • Vehicle Range in Miles • Visibility - Ergonomics • Body Strength • Options Available
Six Engineering Concepts • Design • Systems • Optimization • Modeling • Ethics • Technology Society Integration
Systems Thinking Creativity Optimism Collaboration Communication Ethical Considerations Critical and analytical thinking, Accepting feedback and learning from mistakes, Perseverance with difficult or ambiguous tasks Drawing inferences and reaching conclusions based on an evaluation of sources and their Supporting opinions with logical arguments EPIC - “Pre-Engineering and Applied Science Project”, 2007 Engineering Habits of Mind The Status and Nature of K-12 Engineering Education in the United States, by Linda Katehi, Greg Pearson, and Michael Feder. The Bridge-Linking Engineering and Society - 2009
IdeationHow to Arrive at Ideas • Brainstorming • Attribute Listing • Matrix Checklist • Synectics • Nominal Group Technique • The Delphi Technique Engineering - An Introduction to a Creative Profession, Beakley, Evans, Keats, pps.354-362, Macmillan, 1986
Norms of Innovation • Mistakes OK • Recognition • Rewards • Mutual Respect • Open Communication • Freedom to Experiment • Challenge the Status Quo • Equal Partners Winning Through Innovation - Harvard Business School Press, Boston, Mass, 1997
Conceptual Blockbusting • Perceptual Blocks • Cultural and Environmental Blocks • Emotional Blocks • Intellectual and Expressive Blocks • Alternate Thinking Languages Conceptual Blockbusting - A Guide To Better Ideas, 4th Ed., by James L. Adams, Basic Books, 2001
Object - Devise as many ways as possible to get the ping pong ball out of the pipe without damaging the ball, pipe or floor. Cultural & Environmental Blocks 6 people in Room Found Items include: 100’ Clothesline Claw Hammer Chisel Box of Wheaties File Wire Coat Hanger Pipe Wrench Light bulb Ping Pong Ball 4” Metal Pipe Pipe is .06” larger in dia than the 1.50” Ping Pong Ball Concrete Floor Conceptual Blockbusting - A Guide To Better Ideas, 4th Ed. by James L. Adams, Basic Books, 2001
Chassis Steering Suspension Entertainment Restraint and Safety Power Train Hybrid System Fuel Electrical Harness Fuse System Temperature Control Navigation (GPS) OnStar System Monitoring Engine or Motor Cooling Recyclable ID Braking Windshield washer Sub Systems Designed into a Transportation System
Car Fuse System Model ControlAdjust PROCESS INPUT OUTPUT Identify all fuseable circuits. Connect fuses in series and incorporate into an optimal/easy access fuse box. Assign proper amp ratings & fuse types as per circuit requirements.. Design a fuse system that protects all incorporated electrical circuits & devices. All circuits are adequately protected and operate normally. Fuses fail at safe current levels. Feedback Human detection, Circuit functions properly or fuses fail - indicating a problem. Computer diagnostics & alarm.
System Model ControlAdjust INPUT PROCESS OUTPUT Set heat or air conditioning controls to desired comfort levels. Maintain a cabin or interior Temp. of 70 degs.F Desired Temp. or comfort level is achieved Feedback Human, Instrument Computer,,,, etc… Temperature Control System
NHTSA - IIHSCrash Safety • Subaru– 6 Models with 5 star ratings (frontal and side impacts) • Volvo – 5 Models with 5 star ratings (frontal and side impacts) • Ford Explorer / Ford Taurus / BMW 5 Star ratings (frontal & side impacts) • Suzuki Equator 4 Star Frontal 1 Star Side impact.
Alternate Approach Wall Sand Bag Car Pulleys
Integrating Green Into Automobiles • Increase fuel efficiency via new approaches • Decrease weight via composites, etc. • Integrate Hybrid Systems Fuel Cells-Battery Electric-Propane • Design with Recyclable Plastics In Mind • Design with Biodegradable Materials • Enhance Metal Recovery for Reuse • Refurbursh and Rebuild Parts.
Recycling Auto Parts ReUsed Glass-Artifical Sand -Asphalt -Landscaping Car Seats Electronics Upholstery 90% of Alum. Gets Recycled 90% of Metals, Plastics and Textiles can be recycled. Battery -Polypropelene Case -Lead reuse- Acid reuse Recycled Bumpers Oil + Filter Recycle Recycled Steel is used to Manuf.13 Million new vehicles/Yr. Carpets Alternators - Water Pumps Windshield Motors Retread - Planters -Rubberized ‘Roads
Crash Model Body Assembly Springs - Shock Absorbers Foam or Hard Rubber Honey Comb Cells Body Flex Body Reverse Engineered 3D Modeled Vacuum Formed Egg Protection Passive & Active Crumple Zone Carriage Can be used multiple times Recyclable Polystyrene or Polypropelene Multiple Metal Plates can be reused
Dashboard Design & System Integration Research and Observe Current Features Gee Whiz Exercise - Incorporate New Features/Systems Build in Ergonomic Considerations Build in Environmentally Friendly Features
Speed Conversion 5280 ft/mi divided by 3600 sec./ hr = 1.47 ft/sec/mph 1 MPH = 1.47 feet per second Traveling at 30 mph = how many feet / second? 30 mph x 1.47 ft/sec/mph = 44.1 Ft/Sec Greater distance than your typical home is long. 68 mph x 1.47 ft/sec/mph = 99.96 ft/sec Equivalent to 1/3 of a football field
Speed = Distance / Time Speed is how fast an object is moving without reference to direction. Velocity is how fast an object is moving while knowing its direction of travel. SPEED = Distance = 300 feet = Time 5 secs 60 ft/sec 5280 Ft/mi = 1.47 ft/Sec. = 1mph 3600 Secs./Hr. 60 Ft/Sec = 1.47Ft/Sec/mph 40.82mph
Acceleration Due To Gravity Acceleration due to G = 9.8 m/s2 An Object falling for 3 seconds = has a Vel. of 29.4 m/s. An object falling for 7 seconds has a Vel. of 68.6 m/s. 1s - 9.8m/s 2s -19.6m/s 3s - 29.4m/s What is Terminal Velocity? 7s - 68.6m/s
Number of CollisionsIn a Car Crash • Collision 1 - When the Car collides with another car or object. • Collision 2 - When our bodies are thrown in the direction of force and collide with the car’s interior + seat belts & air bags. • Collision 3 - Body organs (brain, intestines, etc. collide with our cranium and skeletal frame. • Collision 4 - Impact with loose objects located within the car (pets, boxes, books, groceries, etc..)
Metric to EnglishEnglish to MetricMass vs Weight I pound = .4536 Kg’s 1 Pound = .0311 Slugs I Kg = 2.205 lbs 1 Slug = 32.174 lbs 1 Slug = 14.6 kg & 143 N 1Kg = 9.802 Newtons 1 Newton = .102 Kg’s 1 Newton = .225 Lbs 1 pound = 4.448 Newtons
Metric to EnglishEnglish to MetricLinear Distances & Speed • Feet = .0348 Meters • Meters = 3.281 Feet • Yard = .9144 Meters • Meter = 1.09 Yards • Miles = 1.61km • Mile = 5280 ft = 1760 Yds = 1614.68m • Km = .6214 miles • 50kph = 31.1 mph • 65 mph = 104.65 kph
Momentum Momentum ( P ) = Mass x Velocity Impetus, impelling force or strength of a physical object in motion. P = m x v Mass = 910 Kg Vel = 70 m/sec P = 910kg x 70m/sec = 63,700 kg-m/s P = 5.3 kg x 25.92 ft/sec = 137.376 kg-m/s
Impulse Impulse (I) is the product of the applied force and the time for which it is applied. Impulse (I) = Fave x change in time (∆t) Impulse (I) = Change in Momentum I = F x ∆t orI = F x ∆t I = 1000 N x 2 secs = 2000 N-secs (Higher) I = 1000 N x .2 secs = 200 N-secs (Lower) Airbags Deploy .015ms to .025ms F ∆t = ∆Pmom Accident Duration 125 ms or 1/8 sec.
Reducing Impulse • Applying Brakes • Crumple Zone Collapse • Air Bag Deployment (Frontal & Side) • Padded and/or Crumple Dashboard • Safety Glass • Seat Belts • Collapsible Steering Column • Seat Padding • Head Rest/Restraint
Newton’s Second Law Force = Mass x Acceleration F = ma Mass = 11.65 lbs = 5.3 Kg 2.2lbs/Kg F = 5.3 kg x 9.81 m/s = 52 kg m/s 2 2 2 1 kg m/s = 1 Newton - hence 52 Newtons = 52 Apples
Coefficient of Friction • Static Friction µs = F/N • Kinetic Friction µk = F/N • Rolling Friction µR = F/N
Coefficient of Friction Force of Friction 80N Applied Force 155 N µs = 98N = 155N .63 Normal Force
Calculating Reaction Time 2 d = 1/2 gt t = 2 d g .306 s t = 2 x 1.5 ft = 32 ft/sec 2 0.25 secs. t = 2 x 1 ft = 32 ft/sec 2
Potential Velocityof Crash Vehicle Velocity = 2g∆H 2 g = 32ft/sec ∆H = Ramp = 10.5 ft. 2 Velocity = 2 x 32ft/sec x 10.5 ft 2 Velocity = 672 ft / sec 2 Velocity = 25.92 ft/sec Velocity = 25.92 ft/sec / 1.47 ft/sec/mph = 17.633 mph
Scaled Velocity of Model Vehicle Total Linear Distance from Ramp Top to Wall = 20 feet Time to cover that distance = 1.82 Secs Model Scale: ½” = 1 foot or 12 inches= 24 Scaled ft/foot Scaled Distance = 20 ft x 24 scaled ft /1ft = 480 scaled ft 480 scaled ft divided by 1.82 secs = 263 Scaled ft/sec 263 scaled feet/sec divided by 1.47 ft/sec/mph = 178.91mph
Work and Power Work = Force x Distance = Foot - Pounds Work = Force x Distance = Newton - Meters Power = Work / time = Foot - Pounds Or N - M Or Joules Second Sec Sec
Horsepower The ability of a horse to lift up a weight of 550 pounds to a height of one foot in one second. 1 H.P. = 746 Watts OR 746 N-m Sec 1 H.P. = 746 Joules / Second 1 H.P. = 550 ft-lbs Sec
Potential and Kinetic EnergyOf Your Crash Vehicle PE = mgh or Weight x Height PE = 11.65 lbs x 10.5 feet (Ramp Ht) PE = 122.33 ft. lbs or 166.21 N-M 1 Slug x 32.2 ft/sec = 32.2 lbs 2 11.65 lbs divided by 32.2 lbs/slug = .362 Slugs 2 KE = 1/2 mV 2 2 KE = 1/2 x .362 slugs x (25.92 ft/sec ) KE = 121.60 ft lbs or 165.38 N-M
Ratios Egg Weight Model Car Wt. Average Human Weight Average Car Weight Egg Weight Average Human Weight Model Weight Average Car Weight 1 lb = 454 grams 3lbs = 1362 grams 66.6 g / 1362 g = 1 /20 ratio 170 lbs / 3357 lbs = 1 / 19.75 ratio