Engineering Design: A Project-Based Introduction, 4th Edition [Rental Edition]

Foreword x

Preface xi

Acknowledgments xvi

Part I Introduction 1

Chapter 1 Engineering Design 3
What does it mean to design something? Is engineering design different from other kinds of design?

1.1 Where and when do engineers design? 3

1.2 A basic vocabulary for engineering design 7

1.2.1 Defining engineering design 7

1.2.2 Assumptions underlying our definition of engineering design 8

1.2.3 Measuring the success of an engineered design 9

1.2.4 Form and function 9

1.2.5 Design and systems 10

1.2.6 Communication and design 10

1.3 Learning and doing engineering design 12

1.3.1 Engineering design problems are challenging 12

1.3.2 Learning design by doing 13

1.4 Managing engineering design projects 14

1.5 Notes 15

Chapter 2 Defining a Design Process and a Case Study 16
How do I do engineering design? Can you show me an example?

2.1 The design process as a process of questioning 16

2.2 Describing and prescribing a design process 19

2.3 Informing a design process 24

2.3.1 Informing a design process by thinking strategically 24

2.3.2 Informing a design process with formal design methods 24

2.3.3 Acquiring design knowledge to inform a design process 25

2.3.4 Informing a design process with analysis and testing 26

2.3.5 Getting feedback to inform a design process 27

2.4 Case study: Design of a stabilizer for microlaryngeal surgery 27

2.5 Illustrative design examples 34

2.6 Notes 35

Part II The Design Process and Design Tools 37

Chapter 3 Problem Definition: Detailing Customer Requirements 39
What does the client require of this design?

3.1 Clarifying the initial problem statement 40

3.2 Framing customer requirements 41

3.2.1 Lists of design attributes and of design objectives 41

3.3 Revised problem statements: Public statements of the design project 43

3.4 Designing an arm support for a CP-afflicted student 44

3.5 Notes 46

Chapter 4 Problem Definition: Clarifying the Objectives 47
What is this design intended to achieve?

4.1 Clarifying a client’s objectives 47

4.1.1 Representing lists of objectives in objectives trees 49

4.1.2 Remarks on objectives trees 50

4.1.3 The objectives tree for the juice container design 51

4.2 Measurement issues in ordering and evaluating objectives 53

4.3 Rank ordering objectives with pairwise comparison charts 54

4.3.1 An individual’s rank orderings 54

4.3.2 Aggregating rank orderings for a group 55

4.3.3 Using pairwise comparisons properly 56

4.4 Developing metrics to measure the achievement of objectives 57

4.4.1 Establishing good metrics for objectives 58

4.4.2 Establishing metrics for the juice container 61

4.5 Objectives and metrics for the Danbury arm support 62

4.6 Notes 66

Chapter 5 Problem Definition: Identifying Constraints 67
What are the limits for this design problem?

5.1 Identifying and setting the client’s limits 67

5.2 Displaying and using constraints 68

5.3 Constraints for the Danbury arm support 69

5.4 Notes 70

Chapter 6 Problem Definition: Establishing Functions 71
How do I express a design’s functions in engineering terms?

6.1 Establishing functions 71

6.1.1 Functions: Input is transformed into output 72

6.1.2 Expressing functions 72

6.2 Functional analysis: Tools for establishing functions 73

6.2.1 Black boxes and glass boxes 73

6.2.2 Dissection or reverse engineering 75

6.2.3 Enumeration 76

6.2.4 Function–means trees 79

6.2.5 Remarks on functions and objectives 80

6.3 Design specifications: Specifying functions, features, and behavior 81

6.3.1 Attaching numbers to design specifications 81

6.3.2 Setting performance levels 84

6.3.3 Interface performance specifications 85

6.3.4 House of quality: Accounting for the customers’ requirements 86

6.4 Functions for the Danbury arm support 88

6.5 Notes 91

Chapter 7 Conceptual Design: Generating Design Alternatives 92
How do I generate or create feasible designs?

7.1 Generating the “design space,” a space of engineering designs 92

7.1.1 Defining a design space by generating a morphological chart 93

7.1.2 Thinking metaphorically and strategically 95

7.1.3 The 6–3–5 method 97

7.1.4 The C-sketch method 98

7.1.5 The gallery method 98

7.1.6 Guiding thoughts on design generation 99

7.2 Navigating, expanding, and contracting design spaces 99

7.2.1 Navigating design spaces 99

7.2.2 Expanding a design space when it is too small 100

7.2.3 Contracting a design space when it is too large 101

7.3 Generating designs for the Danbury arm support 101

7.4 Notes 105

Chapter 8 Conceptual Design: Evaluating Design Alternatives and Choosing a Design 106
Which design should I choose? Which design is “best”?

8.1 Applying metrics to objectives: Selecting the preferred design 106

8.1.1 Numerical evaluation matrices 107

8.1.2 Priority checkmark method 109

8.1.3 The best-of-class chart 110

8.1.4 An important reminder about design evaluation 111

8.2 Evaluating designs for the Danbury arm support 111

8.3 Notes 113

Part III Design Communication 115

Chapter 9 Communicating Designs Graphically 117
Here’s my design; can you make it?

9.1 Engineering sketches and drawings speak to many audiences 117

9.2 Sketching 119

9.3 Fabrication specifications: The several forms of engineering drawings 122

9.3.1 Design drawings 122

9.3.2 Detail drawings 125

9.3.3 Some Danbury arm support drawings 126

9.4 Fabrication specifications: The devil is in the details 127

9.5 Final notes on drawings 129

9.6 Notes 130

Chapter 10 Prototyping and Proofing the Design 131
Here’s my design; how well does it work?

10.1 Prototypes, models, and proofs of concept 132

10.1.1 Prototypes and models are not the same thing 132

10.1.2 Testing prototypes and models, and proving concepts 133

10.1.3 When do we build a prototype? 134

10.2 Building models and prototypes 135

10.2.1 Who is going to make it? 136

10.2.2 Can we buy parts or components? 136

10.2.3 How, and from what, will the model/prototype be made? 137

10.2.4 How much will it cost? 141

10.3 Notes 141

Chapter 11 Communicating Designs Orally and in Writing 142
How do we let our client know about our solutions?

11.1 General guidelines for technical communication 143

11.2 Oral presentations: Telling a crowd what’s been done 145

11.2.1 Knowing the audience: Who’s listening? 145

11.2.2 The presentation outline 146

11.2.3 Presentations are visual events 147

11.2.4 Practice makes perfect, maybe . . . 148

11.2.5 Design reviews 149

11.3 The project report: Writing for the client, not for history 150

11.3.1 The purpose of and audience for the final report 151

11.3.2 The rough outline: Structuring the final report 151

11.3.3 The topic sentence outline: Every entry represents a paragraph 152

11.3.4 The first draft: Turning several voices into one 153

11.3.5 The final, final report: Ready for prime time 154

11.4 Final report elements for the Danbury arm support 155

11.4.1 Rough outlines of two project reports 155

11.4.2 ATSO for the Danbury arm support 157

11.4.3 The final outcome: The Danbury arm support 158

11.5 Notes 158

Part IV Design Modeling, Engineering Economics, and Design Use 159

Chapter 12 Mathematical Modeling in Design 161
Math and physics are very much part of the design process!

12.1 Some mathematical habits of thought for design modeling 162

12.1.1 Basic principles of mathematical modeling 162

12.1.2 Abstractions, scaling, and lumped elements 162

12.2 Some mathematical tools for design modeling 163

12.2.1 Physical dimensions in design (i): Dimensions and units 164

12.2.2 Physical dimensions in design (ii): Significant figures 166

12.2.3 Physical dimensions in design (iii): Dimensional analysis 167

12.2.4 Physical idealizations, mathematical approximations, and linearity 169

12.2.5 Conservation and balance laws 171

12.2.6 Series and parallel connections 173

12.2.7 Mechanical–electrical analogies 176

12.3 Modeling a battery-powered payload cart 177

12.3.1 Modeling the mechanics of moving a payload cart up a ramp 177

12.3.2 Selecting a battery and battery operating characteristics 181

12.3.3 Selecting a motor and motor operating characteristics 184

12.4 Design modeling of a ladder rung 186

12.4.1 Modeling a ladder rung as an elementary beam 188

12.4.2 Design criteria 190

12.5 Preliminary design of a ladder rung 193

12.5.1 Preliminary design considerations for a ladder rung 193

12.5.2 Preliminary design of a ladder rung for stiffness 194

12.5.3 Preliminary design of a ladder rung for strength 195

12.6 Closing remarks on mathematics, physics, and design 196

12.7 Notes 196

Chapter 13 Engineering Economics in Design 197
How much is this going to cost?

13.1 Cost estimation: How much does this particular design cost? 197

13.1.1 Labor, materials, and overhead costs 198

13.1.2 Economies of scale: Do we make it or buy it? 200

13.1.3 The cost of design and the cost of the designed device 200

13.2 The time value of money 201

13.3 Closing considerations on engineering and economics 204

13.4 Notes 204

Chapter 14 Design for Production, Use, and Sustainability 205
What other factors influence the design process?

14.1 Design for production: Can this design be made? 206

14.1.1 Design for manufacturing (DFM) 206

14.1.2 Design for assembly (DFA) 207

14.1.3 The bill of materials and production 209

14.2 Design for use: How long will this design work? 209

14.2.1 Reliability 210

14.2.2 Maintainability 214

14.3 Design for sustainability: What about the environment? 215

14.3.1 Environmental issues and design 215

14.3.2 Global climate change 217

14.3.3 Environmental life-cycle assessments 218

14.4 Notes 218

Part V Design Teams, Team Management, and Ethics in Design 221

Chapter 15 Design Team Dynamics 223
We can do this together, as a team!

15.1 Forming design teams 223

15.1.1 Stages of group formation 224

15.1.2 Team dynamics and design process activities 226

15.2 Constructive conflict: Enjoying a good fight 227

15.3 Leading design teams 229

15.3.1 Leadership and membership in teams 229

15.3.2 Personal behavior and roles in team settings 230

15.4 Notes 231

Chapter 16 Managing a Design Project 232
What do you want? When do you want it? How much are we going to spend?

16.1 Getting started: Establishing the managerial needs of a project 232

16.2 Tools for managing a project’s scope 234

16.2.1 Team charters 234

16.2.2 Work breakdown structures 237

16.3 The team calendar: A tool for managing a project’s schedule 241

16.4 The budget: A tool for managing a project’s spending 243

16.5 Monitoring and controlling projects: Measuring a project’s progress 245

16.6 Managing the end of a project 248

16.7 Notes 249

Chapter 17 Ethics in Design 250
Design is not just a technical matter

17.1 Ethics: Understanding obligations 250

17.2 Codes of ethics: What are our professional obligations? 252

17.3 Obligations may start with the client . . . 255

17.4 . . . But what about the public and the profession? 256

17.5 On engineering practice and the welfare of the public 261

17.6 Ethics: Always a part of engineering practice 263

17.7 Notes 263

Appendices 264

Appendix A Practical Aspects of Prototyping 264

A.1 Working safely in a shop 264

A.2 Selecting materials 265

A.3 Building techniques 267

A.4 Selecting a fastener 269

Fastening wood 270

Fastening polymers 273

Fastening metals 274

What size temporary fastener should I choose? 278

A.5 Notes 278

Appendix B Practical Aspects of Engineering Drawing 279

B.1 Dimensioning 279

Orthographic views 279

Metric versus inch dimensioning 282

Line types 283

Orienting, spacing, and placing dimensions 284

Types of dimensions 284

Some best practices of dimensioning 285

B.2 Geometric tolerancing 286

The 14 geometric tolerances 287

Feature control frames 287

Material condition modifiers 290

Datums 292

Position tolerance 295

Fasteners 296

B.3 How do I know my part meets the specifications in my drawing? 298

B.4 Notes 299

Appendix C Exercises 300

References and Bibliography 309

Index 315