Chapter 3 Dr. Bahaa Al-Sheikh & Eng. Mohammed Al-Sumady Intoduction to Engineering Introduction to Engineering Design 1

 Engineers, regardless of their backgrounds, follow certain steps when designing the products and services we use in our every day lives. 2

In this chapter we will Introduce you to the engineering design process Discuss the basic steps that most engineers follow when designing a product Discuss the importance of considering sustainability in design 3

Introduce important design factors such as  Teamwork  Project scheduling  Material selection  Economic consideration  Engineering standards and codes Present cases studies in civil, mechanical/ electrical engineering 4

The main objective of this chapter is: To introduce the steps engineers follow to successfully design products or provide services that we use in our everyday lives 5

Design Process – Basic Steps: 1. Recognizing the need for a product or a service 2. Problem definition and understanding 3. Research and preparation 4. Conceptualization 5. Synthesis 6. Evaluation 7. Optimization 8. Presentation 6

 Step 1: Recognizing the need for a product or a service 7

Step 2: Problem definition and understanding This is the most important step in any design process Before you move on to the next step  Make sure you understand the problem  Make sure that the problem is well defined Good problem solvers are those who first fully understand what the problem is. 8

Step 3: Research and preparation (Project Panning) Collect useful information  Search to determine if a product already exists  Perhaps you could adopt or modify existing components  Review and organize the information collected in a suitable manner 9

Step 4: Conceptualization ( Brainstorming) Generate ideas or concepts that could offer reasonable solutions to your problem 10

Step 5: Synthesis At this point you begin to consider details Perform calculations, run computer models, narrow down the type of materials to be used, size the components of the system, and answer questions about how the product is going to be fabricated. Consult pertinent codes and standards and make sure that your design will be in compliance with these codes and standards. 11

Step 6: Evaluation Analyze the problem in more detail Identify critical design parameters and consider their influence in your final design Make sure that all calculations are performed correctly Experimental Investigations. When possible, working models must be created and tested. Best solution must be identified from alternatives Details of design must be worked out fully 12

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Step 7: Optimization – minimization or maximization Optimization is based on some particular criterion such as cost, strength, size, weight, reliability, noise, or performance. Optimizing individual components of an engineering system does not necessarily lead to an optimized system 14

 Step 7: Optimization – minimization or maximization  Example : Designing a ladder with specific height and safety support weight.  Consider the weight of the ladder as an optimization criterion.  Then the problem becomes one of minimizing the weight of the ladder without jeopardizing its strength. 15

16 An optimization procedure

 Step 8: Presentation 17

Step 8: Presentation You need to communicate your solution to the client, who may be your boss, another group within your company, or an outside customer Engineers are required to give oral and written progress reports on a regular basis to various groups; consequently, presentation could well be an integral part of many other design steps 18

 The marketing department at Johnson outdoors recognized the growing interest in environmentally friendly power sources for their boating industry. 19

 To better serve the consumer and environment.  Increasingly, more states were enacting regulations banning the use of gasoline boat motors in public water ways including lakes and rivers. 20

 Details of the project were defined.  Design specifications: ◦ The motor had to move 17 feet long Pontoon at speed of 5 mph minimum. ◦ The motor has to run at least 2 hours on full battery charge. ◦ The boat operator has the ability to trim and tilt (raise the motor out the water) from a remote console. ◦ The motor has to be compatible with industry standard steering wheel mechanics. 21

 Check if the motor already exists and meet some or all requirements.  Look at state regulations concerning the use of gasoline vs. Electric boat motors. 22

 Engineers meet weekly to brain storm and bounce ideas.  Review information gathered in step three.  Idea: the use of electric linear actuator in place of hydraulic actuator.  This idea was perused further because the potential leaks associated with hydraulic actuators. 23

 Considering details.  Make sure that their design is in compliance with codes and standards.  Most of design work was done in ProE  Prototypes were build in machine laboratories. 24

 Numerical experiments were conducted using ProMechanica.  Finite element techniques used to study stresses in critical components.  Numerical experiments were performed to study the hydrodynamics.  The speed of the motor was measured over several hours.  Acceleration and position time function were determined and compared with competitors'’ motors. 25

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 Based on results in step 6 modifications on the design were made to improve performance.  Better withstand loading conditions.  More testing  Actual field testing in water and simulated life resting in labs. 27

 The product development process took approximately 2 years.  During this period the design engineers gave weekly progress reports.  Quarterly status oral and written reports  Final presentation was given to the Board directors.  Presentation covers main issues regarding: development cost, unit cost, market outlook, performance characteristics, test results and environmental impact.  Range from 15 min to entire afternoon. 28