6 Modeling, Testing, and Final Outputs

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Objectives Explain the importance of predictive analysis to the engineering design process. Describe principles used in mathematical modeling. Identify different types of physical modeling. Discuss how computer modeling is used in different engineering fields. Explain the testing process. Describe different types of final outputs.

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. The Engineering Design Process Goodheart-Willcox Publisher

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Modeling Type used depends on field Areas of modeling –Mathematical models –Physical models –Computer models Used for simulating design and testing solutions

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Mathematical Modeling Mathematical prediction –Uses mathematical formulas and problems –Predicts results of design Highly dependent on field of engineering Predictions made by mathematical principles –How materials respond to stress –How chemicals will work together –How electricity will travel through circuits

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Mathematical Model Example Goodheart-Willcox Publisher

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Units of Measurement Angle Length Area Volume Mass Force Torque Pressure Energy Power

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Fields of Mathematics Algebra Geometry Trigonometry Calculus Statistics Probability

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Formulas Represent concepts and predict outcomes Use numbers and letters Common formulas used in engineering –Amount of work performed by a machine –Amount of power in a system –Ohm’s law –Bernoulli’s principle Formulas used depends on engineering field

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Physical Modeling 3-D replicas of final design Uses of physical models –Illustrate design –Test design –Experiment with materials Two categories of physical models –Mock-ups –Prototypes

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Mock-Ups Primary uses –Demonstrate object to others –Illustrate features of object –Evaluate design Sometimes used to obtain feedback Usually created with less expensive material than final design Provide overall appearance of design

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Prototypes Working products Simulate function of final object Rapid prototyping –Uses a computer modeling program –Machine takes information from CAD program –Builds product by building layers of plastic

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. 3-D Printers Used to create models of objects Use plastic placed in layers Receive file of engineer’s design Heat plastic and layer it to create object Technology has changed dramatically over past 20 years –Prices have been reduced –Can be used by consumers at home Tools

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling Has replaced many other methods of modeling in last 30 years Software used to create simulations –Predictive analysis –Virtual tests on designs –Ability to change different components Specific programs for different disciplines

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Chemical Engineering Uses process simulators –Use diagrams –Show flow of chemical processes Models of chemical properties Shows mass and energy balances of chemicals

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Mechanical Engineering Creates functional computer models Modifies features of basic shapes to create visual working models Designs often sent to “production” –CNC devices –Rapid prototyping machines Adjustments can be continually made to design through the software

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Bioengineering Focus on biology and agriculture –Uses environmental simulation software –Determines dynamics and properties of earth Focus on medicine –Shows impacts of different drugs on patients –Predicts effects of different medications

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Structural Engineering Used to draw and develop plans for structures Allows testing of designs before creation Allows experimentation with different materials Can be used to make 2-D or 3-D drawings

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Electrical Engineering Power system design and analysis software –Allows development of circuits –Calculates voltage flow and electrical load Models show relationship between time and current to find peak times of use

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Electrical Engineering Computer Model Example NASA

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Civil Engineering Geospatial modeling software –Allows for simulation of urban areas –Allows for better organization of urban areas Allows engineers to plan and adapt Allows engineers to take many different factors into consideration

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Computer Modeling in Aerospace Engineering Computational fluid dynamics (CFD) software –Focuses on use of fluids in relationship to flight of airplanes –Used to study how airplanes gain lift in air –Used to study forces that work against flight –Uses many mathematical algorithms and fluid properties Used in conjunction with wind tunnels and flight tests

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Predictive Analysis Distinguishes engineering design from other types of design Determines if solution will solve problem without building actual object Based on statistics and probability Effectiveness can be reduced by assumptions Performed using methods of modeling

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Testing Determines usefulness of product Always done before design is produced Begins with asking questions about design Based on five criteria –Function –Fit –Aesthetics –Safety –Environmental impact

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Function Usually first criterion tested Engineers ask many questions about design –Does the product work? –Will it work in all temperatures? –Can it withstand daily use? –Will it meet minimum requirements? –Will it meet customer expectations? Engineers perform repeated tests on prototype in different conditions

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Fit Object’s ability to fit into production process and use by customer Ask further questions about production and customer needs –Can it be produced efficiently? –Does it fit in consumer’s hand? –Is it comfortable to use? Questions answered with discussions, testing, and letting potential users try the product

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Aesthetics Whether product is visually appealing Engineers ask more questions –Will consumers purchase it based on appearance? –Is it correct size and color? –What could make it more appealing? –Does it look like it can solve the problem? Ask questions to potential customers Product testers might provide feedback

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Safety Always a major consideration Concerned with two forms of safety –Is it safe to produce? –Is it safe for consumers? Further questions to ask –Is material strong enough to support function? –Are there any electrical hazards? –Will any pieces pose a choking hazard? –Does it meet government safety regulations?

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Environmental Impact Whether design is safe for environment Ask further questions –Are waste materials involved with manufacturing? –How will it be disposed of after use? –What is its ecological footprint? –Are there potential risks if it malfunctions? Perform tests on manufacture and materials Follow government environmental regulations

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Engineering Economics Important part of creating and distributing solutions Cost to develop and produce design Cost feasibility of product –Whether or not product is worth producing –If there are opportunities to make a profit Materials are often adjusted before production

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Final Outputs Three types of outputs –Final project reports –Oral presentations –Production documents Share with management team Present information –To client –To community –To other interested group

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Final Project Reports Highly personalized for each specific project Provide information about why solution developed is best option to address problem Provide brief summary of each step in process

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Information Included in Final Project Reports Title page (information about design team) Problem statement Design goals (criteria and constraints) Alternative designs Strengths and weaknesses (trade-off matrix) Information about assembly and manufacture Summary information of all testing Final recommended design (with models)

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Oral Presentations Follow final project report as outlined Illustrations can be shown Some are brief summaries of products Some allow for great detail of report summary Presentation skills are important Audience members often ask questions

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Production Documents Final drawings for many different stakeholders Include appropriate dimensions Include all information needed to produce product Include mathematical information Often include computer models Communicate solution with all members of design team

Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc. Design Improvement Final step in design process Based on feedback –From design team –From management team –From production staff –From consumers Often uses reverse engineering