Engineering Design and Rapid Prototyping

Ali K. Kamrani ● Emad Abouel Nasr

Engineering Design and Rapid Prototyping

ISBN 978-0-387-95862-0 e-ISBN 978-0-387-95863-7DOI 10.1007/978-0-387-95863-7Springer New York Dordrecht Heidelberg London

Library of Congress Control Number: 2010932806

© Springer Science+Business Media, LLC 2010All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden.The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.

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Springer is part of Springer Science+Business Media (www.springer.com)

Ali K. KamraniIndustrial Engineering DepartmentUniversity of HoustonHouston, TX, USAandFatimah Alnijris’s Research Chair for Advanced Manufacturing TechnologyIndustrial Engineering DepartmentKing Saud UniversityRiyadh, Saudi Arabiaakamrani@uh.edu

Emad Abouel NasrFatimah Alnijris’s Research Chair for Advanced Manufacturing TechnologyIndustrial Engineering DepartmentFaculty of EngineeringKing Saud UniversityRiyadh, Saudi ArabiaandMechanical Engineering DepartmentFaculty of EngineeringHelwan UniversityHelwan, Egyptemadsamir60@helwan.edu.eg

To my wife Sonia and sons Arshya and Ariya

Ali KamraniTo my parents, wife, and children Nada, Haidy, and Amr

Emad Abouel Nasr

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Engineering design process consists of a set of activities arranged in a specific order with the clearly identified inputs and outputs. The process of engineering design is an iterative that supports the decision-making activities involved. Each activity in the process takes an input and transforms it into an output of some value defined by design specifications and objectives. The output of the process is either a product, a process, or a service. The objective of the process is to satisfy customer require-ments and management objectives. This process is considered efficient when the output of the process satisfies general customers and defined requirements, meets management objectives and customer deadlines, and all these with less costs and resources. Establishing objectives and criteria, synthesis, analysis, construction, testing, and evaluation are considered as fundamental elements within the design process. Steps in the Engineering design process are illustrated in Fig. 1.

These steps and further described below:

1. Identify the Need/Problem: This step is not always realized by engineers. Problems are typically identified by the market and customers and then passed on to the engineering group to search and develop solutions.

Preface

Fig. 1 Engineering design process

Select BestPossible Solu�on

EngineeringDesign Process

viii Preface

2. Research the Need/Problem: This step is of importance since a solution to the defined problem or portion of the problem may have already existed. Through proper research, time and money can be easily saved.

3. Develop Possible Solutions: In this step, the engineering group will propose different solution alternatives that will solve the problem. These possible solu-tions are made while taking into consideration the information found in the pre-vious steps.

4. Select Best Possible Solution: The engineering group will then use the defined criteria and other methodologies to select the best possible solution. The param-eters on which the engineering group determine if it is the best possible solution may vary depending on the defined constrains and/or the design criteria estab-lished at the beginning of the engineering design process.

5. Construct a Prototype: In this step, the engineering group proceeds to con-struct a prototype of the selected solution. Once the prototype is built, testing is performed to validate the proposed design solution. If the design does not meet the required performance, the engineering design process is repeated until a sat-isfactory solution is implemented.

New global economies and global markets changed business practices and focused on the customer as the major player in the economy. In order to compete in this fast-paced global market, organizations need to produce products that can be easily configured to offer distinctive capabilities compared to the competition. Furthermore, organizations need to develop and implement new engineering meth-ods (e.g., modularity), and apply advanced techniques in design (e.g., Feature-Based Design) and technologies (e.g., Rapid Prototyping) to react rapidly to required changes in products and market trends and to shorten the product develop-ment cycle, which will enable them to gain more economic competitiveness. This requires that the tasks needed to develop products be made in parallel, starting at the early stages of product development. By developing such techniques, organiza-tions will be able rapidly to design changed or new products, to change parts of a product, or to change manufacturing facilities to a new version of a product.

The concept of modularity can provide the necessary foundation for organiza-tions to design products that can respond rapidly to market needs, and allow the changes in product design to happen in a cost-effective manner. Modularity can be applied to the engineering design processes to build modular products. An impor-tant aspect of modular products is the creation of a basic core unit to which different components (modules) can be fitted, thus enabling a variety of versions of the same module to be produced. The core should have sufficient capacity to cope with all expected variations in performance and usage. Components used in a modular product must have features that enable them to be coupled together to form a new product. Figure 2 illustrates the scope of modular design methodology.

Computer-aided design (CAD) and manufacturing (CAM) systems are based on modeling geometric data. The main advantage of CAD/CAM systems is the ability to visualize product design, and support design analysis and manufacturing acti-vates. CAD/CAM systems need the standardization that gives them the ability

ixPreface

to communicate to each other. Different CAD or geometric modeling packages store the information related to the design in their own databases, and the structures of these databases are different from each other. As a result, no common or standard structure has been developed that can be used by all CAD/CAM packages. Therefore, a feature-based approach using IGES standard will provide the required standardization to achieve the integration between CAD and CAM. Figure 3 illus-trates the stages that CAD/CAM and other advanced tools and technologies are used to support, and integrated and intelligent engineering design life cycle.

Rapid Prototyping (RP) is a technique for direct conversion of three—dimen-sional CAD data into a physical prototype. RP allows for automatic construction of physical models and has been used to significantly reduce the time for the product development cycle and to improve the final quality of the designed product. Before the application of RP, computer numerically controlled (CNC) equipments were used to create prototypes either directly or indirectly using CAD data. In RP pro-cess, thin-horizontalcross-sections are used to transform materials into physical prototypes. Steps in RP process cycle are illustrated in Fig. 4.

In the RP process, CAD data are interpreted into the Stereolithography (stl) data format. The stl is the standard data format used by all RP machines. By using “stl”, the surface of the solid is approximated using triangular facets, with a normal vec-tor pointing away from the surface in the solid. Within the last few years, corpora-

Fig. 2 Design for modularity life cycle

Design Concept(Re)Formulation

Design forModularity (DFMo)

Design forAssembly (DFA)

Selection of Materialand Primary Process for Near Net Shape

Feasible/OptimumDesign Concept

Design forManufacture

Template-BasedProcess Planning

ModularManufacturing Cells

Optimization Modelsand Sub-System

Generation

Simplification ofProduct Structure

D

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More EconomicMaterials, Processes

and Machines

Knowledge-BasedEngineering and Decision Trees

Decision Trees andGroup Technology

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r M

od

ula

rity

Optimization Modelsand ManufacturingCells Generation

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Time

Des

ign

and

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ufac

turin

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is

CAD

Rapid Prototyping

Analysis and Re-Design

CAD/CAE

Specificationsand Concepts

Process Planningand CAPP

Design for Manufactureand Assembly Analysis

Manufacturing and Production

Variety andComplexity

Analysis

Fig. 3 CAD/CAM application for EDP

Fig. 4 Generic RP process cycle

Tools forSculptural

Design andStyling

CAD Tool forGeometric Design &

3D Model

Functional & Physical Specifications

Decomposition

RapidPrototyping

ModularComponents

andSubassemblies

STL File Analysis& Editing

Testing

PlanningProduct

& ProcessDevelopment

Product& Process

Testing

Mfg. &Assembly

xiPreface

tion has engaged in studies to integrate their distributed design processes, ranging from marketing to support. Recent government, academic, and industrial sector initiatives have sought advance technologies for developing and managing inte-grated product development environment. Many companies have established a distributed and concurrent design environment for their development purposes. Figure 5 illustrates the scope of today’s extended enterprise.

The early phases of design life cycle are usually top-down. It is at the components level that the design process begins to integrate into sub-assemblies and assemblies till the design becomes a complete entity. The objective of the integration is not only to have compatible units, but also by integration all of the requirements as identified by the need statement are realized. This obvious goal has resulted in a very high cost of redesign and analysis due to poor analysis of design and manufacturing integra-tion. By considering proper integration from the beginning, the problems with the final integration of activities will be significantly reduced.

This book offers insights into the methods and techniques that allow for imple-menting engineering designs by incorporating advanced methodologies and tech-nologies in an integrated approach. This book is a collection of the latest methods and technologies, and it is structured in such a way that it could be used for a variety of advanced design and manufacturing courses. Using advanced CAD/CAM soft-ware tool (e.g., CATIA, and IDEAS) is encouraged to be used for courses that plan to use this book.

The book consists of three sections: (1) Product Development and Managements, (2) CAD/CAM and Features-Based Technologies, and (3) Rapid Design and Manufacturing. Below is a description of each chapter’s content:

Fig. 5 Scope of an extended enterprise

Company A

Company B

Supplier A

ProductPrograms

ProductPrograms

ProductSupport

Programs

Integrated Engineeringand Design

Environment

SharedData

PerformanceData

R&DMarketingEngineeringManufacturingTestingMaintenanceServicePhase out

.

.

.

xii Preface

Chapter 1: Engineering Design and Innovations. This chapter provides the concept of information integration at every stage of product development, col-laboration technology, which is needed for cooperative work. As the assistant of the design and development of new products, integrated design technology plays a very important role. The framework described in this chapter confirms design assumptions and predicts product performance in the early stages of the design process. This will result in a faster product development cycle, with lower associated costs, which can be achieved by eliminating the need to con-stantly build, test, and redesign.

Chapter 2: Product Development Process. This chapter discusses the product development life cycle, which can be defined as a sequence of all the required activities that a company must perform to develop, manufacture, and sell a product. These activities include marketing, research, engineering design, quality assurance, manufacturing, and a whole chain of suppliers and vendors. This chapter provides the concept of product development life cycle, the importance of product develop-ment during the product development life cycle, the major phases of product devel-opment process, benchmarking, the systematic procedure of generating concepts, and finally, a complete case study for understanding the presented concepts.

Chapter 3: Modular Design. This chapter provides the concept of modular design, which is a design technique that can be used to develop complex products using similar components. Modular design can be viewed as the process of producing units that perform discrete functions, and then connecting the units together to provide a variety of functions. This chapter provides the concept of modular design, modularity, product modularity representation, the modular systems development process, the product development process using the design structure matrix, and finally, a complete description for DSM building.

Chapter 4: Design for Modularity. This chapter presents a three-phase methodol-ogy, which is proposed for the development of complex products using the modu-larity concept. The proposed methodology matches the criteria set by the design for functionality, assembly, and manufacture. A detailed discussion of needs analysis, quality function deployment, product requirement analysis, product/concept analy-sis, product physical analysis, product functional analysis, product/concept integra-tion, identification of the Impact of system-level specifications on general functional requirements, similarity index, and optimization-based solution methodology for grouping components into modules is presented in this chapter. Finally, genetic algorithm-based solution methodology and algorithm-based solution methodology for grouping components into modules are described for understanding the presented concepts.

Chapter 5: DFMo case study - Four-Gear speed reducer design. This chapter presents a design for modularity approach which is tested and validated using a test product. The selected test product is of moderate complexity to ensure that effort is focused on applying and validating the proposed approach rather than on attempt-ing to understand a complex product. Maintaining moderate complexity will also

xiiiPreface

show the potential for using the proposed approach in designing complex products or systems.

Chapter 6: Design for Manufacture and Assembly. This chapter presents the con-cepts of design for manufacturing and assembly. Product design is the first step in manufacturing and is where the critical decisions are made that will affect the final form and cost of the product. Design for manufacturing and assembly concentrates on simplifying designs while also evaluating assembly improvements to further enhance the overall design for manufacturability and quality. DFMA is a product development process and improvement methodology that provides a systematic process to achieve improved product design, robustness, and cost reductions through simplifications of the overall design. Finally, many case studies are shown for the purpose of understanding the concepts presented in this chapter.

Chapter 7: Computer-Based Design and Manufacturing. This chapter provides an overview of computer-aided design and manufacturing (CAD/CAM), the most important reasons of using CAD systems in the manufacturing environment, com-puter-integrated manufacturing (CIM), the implementation of the automation in the production organization, the role of CAD/CAM systems in the manufacturing facil-ity, the CAM cycle in a feature-based design environment, and the different types of features.

Chapter 8: Feature Representations. This chapter presents discussions related to feature representation methodologies. It includes the definition of features, wire-frame modeling, surface modeling, boundary representation (B-rep), constructive solid geometry (CGS), and definition of interacting features. These methods are used to facilitate the feature recognition process.

Chapter 9: Feature Extraction Techniques. This chapter presents a brief review of the previous work on the related topics of feature representation and recognitions. The first section describes previous research efforts in the area of feature represen-tation. Previous research in the area of feature recognition is described in the sec-ond section. In third section, a methodology for feature analysis and extraction of prismatic parts for CAM applications is developed and presented. This approach aims to achieve the integration between CAD and CAM.

Chapter 10: Engineering Materials - An Overview. This chapter provides an over-view of material used for manufacturing. One of the most important aspects of mate-rial science involves the study of material’s structure. Introducing a new product or changing an existing one involves many decisions. Although these decisions may seem to be independent, they will have a significant impact on the overall product life cycle, which will in turn influence cost, performance, and service.

Chapter 11: Geometric Dimensioning and Tolerancing. In this chapter, an intro-ductory discussion is provided on the topics of geometric dimension and tolerancing, and its impact on selecting the right manufacturing processes. Also, improvements in measurements provide a need to better understand that variation is unavoidable in manufacturing. However, acceptable levels of variation will result in a good assembly.

xiv Preface

It is important to understand the limits of this variation. After the development of GD&T, drawings became the main tool for communication among design, manufac-turing, testing, etc.

Chapter 12: Rapid Prototyping. This chapter provides an overview of the rapid systems: stereolithography (SLA), solid ground curing (SGC), laminated object manufacturing (LOM), selective laser sintering (SLS), direct shell production cast-ing (DSPC), and fused deposition modeling (FDM).

Chapter 13: DATA Mining Methodology and Techniques. The chapter provides the basic concepts of data mining. Data mining deals with the discovery of hidden knowledge, unexpected patterns, and new rules from large databases. It is regarded as the key element of a much more elaborate process called knowledge discovery in databases, or KDD, which is closely linked to data warehousing. Data mining can bring significant gains to organizations, for example, through better-targeted marketing and enhanced internal performance.

Chapter 14: Group Technology and Application. The chapter provides the con-cepts of group technology and cellular manufacturing. Grouping objects into groups based on the object features has been done using group technology (GT) approaches. Similar components can be grouped into design families, and new designs can be created by modifying an existing component design from the same family. The philosophy of group technology is an important concept in the design of advanced integrated manufacturing systems. Group technology is not an answer to all manufacturing problems, but it is a good management technique to standard-ize efforts and eliminate duplication. A well-designed classification and coding system may result in several benefits for the manufacturing plant.

Ali K. Kamrani, Ph.D., P.E.Emad Abouel Nasr, Ph.D.

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We thank our students that contributed to this book as well as our Publisher, Springer for giving us the opportunity to publish our work.

Acknowledgments

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Part I Product Development and Managements

1 Engineering Design and Innovations ...................................................... 3 1.1 Introduction ...................................................................................... 3 1.2 Technological Innovation ................................................................. 4 1.3 Market Trend .................................................................................... 5 1.4 Design Process ................................................................................. 7 1.5 Traditional Product Development Process ....................................... 9 1.6 Integrated Product Development ..................................................... 9 1.7 Teams ............................................................................................... 12 1.8 Effectiveness of PDT ....................................................................... 13 1.9 Collaborative Engineering ............................................................... 141.10 Collaborative Development Process ................................................ 151.11 A Template for Collaborative Design and Implementation .............. 161.12 Summary .......................................................................................... 211.13 Review Questions ............................................................................ 21References ................................................................................................... 22

2 Product Development Process .................................................................. 232.1 Introduction ...................................................................................... 232.2 The Evolution of Product Development .......................................... 242.3 Sequential Product Development ..................................................... 252.4 Simultaneous/Integrated Product Development .............................. 262.5 Generic Product Development Process ............................................ 26

2.5.1 Needs Recognition ............................................................. 272.5.2 Design Specifications ......................................................... 302.5.3 Conceptual Design ............................................................. 322.5.4 Concept Generation ........................................................... 332.5.5 Concept Selection .............................................................. 342.5.6 Final Concept Preliminary Design ..................................... 352.5.7 Detail Design ..................................................................... 352.5.8 Component Final Design ................................................... 352.5.9 Cost Estimation .................................................................. 36

2.5.10 Prototyping ......................................................................... 36

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2.5.11 Production .......................................................................... 362.5.12 Marketing ........................................................................... 37

2.6 An Automatic Ice Maker Case Study (Based on the Work Done by Madriz and Saenzay, University of Houston, 2005) ......... 372.6.1 Overview ............................................................................ 372.6.2 Procedure ........................................................................... 38

2.7 Summary .......................................................................................... 522.8 Review Questions ............................................................................ 54References ................................................................................................. 56

3 Modular Design ......................................................................................... 573.1 Introduction ...................................................................................... 573.2 Modularity Types ............................................................................. 59

3.2.1 Modularity in Products ...................................................... 593.2.2 Modularity in Design Problems ......................................... 59

3.3 Modular Systems Characteristics ..................................................... 603.3.1 Categories of Modules ....................................................... 603.3.2 Product Modularity Representation ................................... 61

3.4 Modular Systems Development ....................................................... 633.4.1 Decomposition Categories ................................................. 643.4.2 Problem Decomposition ..................................................... 663.4.3 Process Decomposition ...................................................... 69

3.5 Survey of Some Modularity Techniques .......................................... 693.5.1 Product Representation for Modular Design ..................... 703.5.2 Dependence and Similarity ................................................ 70

3.6 Design Methods ............................................................................... 713.6.1 Systematic Methods ........................................................... 713.6.2 Other Methods ................................................................... 73

3.7 Design Structure Matrix ................................................................... 743.7.1 The Design Structure Matrix Approach ............................. 753.7.2 DSM Types ........................................................................ 753.7.3 Building the DSM .............................................................. 773.7.4 Partitioning the DSM ......................................................... 793.7.5 Tearing the DSM ................................................................ 80

3.7.6 Comments on DSM and Product Development Improvement .............................................. 81

3.8 Modularity Advantages .................................................................... 813.8.1 Reduction in Product Development Time .......................... 823.8.2 Customization and Upgrades ............................................. 823.8.3 Cost Efficiencies Due to Amortization .............................. 833.8.4 Quality ................................................................................ 833.8.5 Design Standardization ...................................................... 833.8.6 Reduction in Order Lead-Time .......................................... 83

3.9 Summary .......................................................................................... 833.10 Review Questions ............................................................................ 84References ................................................................................................... 84

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4 Design for Modularity .............................................................................. 874.1 Introduction ...................................................................................... 874.2 Needs Analysis ................................................................................. 89

4.2.1 Kano’s Model of Customer Satisfaction .............................. 914.3 Quality Function Deployment .......................................................... 94

4.3.1 Introduction .......................................................................... 944.3.2 The House of Quality ........................................................... 954.3.3 Building the House of Quality ............................................. 974.3.4 Implementing Quality Function Deployment ...................... 994.3.5 Benefits of Quality Function Deployment ........................... 100

4.4 Product Requirements Analysis ....................................................... 1004.4.1 Functional Objectives .......................................................... 1014.4.2 Operational Functional Requirements ................................. 1014.4.3 General Functional Requirements ....................................... 102

4.5 General Functional Requirements’ Weights ..................................... 1024.6 Product/Concept Analysis ................................................................ 1034.7 Product Physical Decomposition ..................................................... 1044.8 Product Functional Decomposition .................................................. 1044.9 Product/Concept Integration ............................................................ 106

4.9.1 Identify System-Level Specifications .................................. 1064.9.2 Functional Characteristics .................................................... 1064.9.3 Physical Characteristics ....................................................... 106

4.10 Identify the Impact of System-Level Specifications on General Functional Requirements ............................................... 1074.11 Similarity Index ............................................................................... 1084.12 Optimization-Based Solution Methodology for Grouping Components into Modules ......................................... 1094.13 Genetic Algorithm-Based Solution Methodology ........................... 110

4.13.1 Genetic Algorithms .............................................................. 1104.13.2 Proposed Model ................................................................... 112

4.14 Algorithm-Based Solution Methodology for Grouping Components into Modules ......................................... 1174.15 Summary .......................................................................................... 1194.16 Review Questions ............................................................................ 120References ................................................................................................... 120

5 DFMo Case Study: Four-Gear Speed Reducer Design.......................... 1235.1 Introduction ...................................................................................... 1235.2 Problem Description ........................................................................ 1235.3 Needs Analysis ................................................................................. 124

5.3.1 Recording the Voice of the Customer .................................. 1245.3.2 Product Features/Metrics Identification ............................... 1245.3.3 Building the House of Quality ............................................. 125

5.4 Product Requirements Analysis ....................................................... 1255.4.1 Functional Objectives .......................................................... 1255.4.2 Operational Functional Requirements ................................. 125

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5.4.3 General Functional Requirements ...................................... 126 5.4.4 General Functional Requirements’ Weights ....................... 126

5.5 Product Concept Analysis ................................................................ 126 5.5.1 Product Physical Decomposition ....................................... 126 5.5.2 Product Functional Decomposition .................................... 127

5.6 Product/Concept Architecture .......................................................... 127 5.6.1 System-Level Specifications .............................................. 127 5.6.2 Impact of the System-Level Specifications

on the General Functional Requirements ........................... 1305.7 Grouping Components into Modules Using Genetic Algorithm Model ................................................................ 1335.8 Summary .......................................................................................... 1375.9 Review Question .............................................................................. 137

5.10 Engineering Design Specifications .................................................. 138

6 Design for Manufacture and Assembly ................................................... 1416.1 Introduction ...................................................................................... 1416.2 DFMA Methodology ........................................................................ 1426.3 The Boothroyd–Dewhurst Method for Manual Assembly Analysis ........................................................ 145

6.3.1 Manual Assembly ............................................................... 1466.4 Case Study: DFA Analysis of a Fog Lamp Design .......................... 148

6.4.1 Alternative Fog Lamp Designs .......................................... 1506.5 LUCAS Design for Assembly Analysis and Evaluation Method ........................................................................... 1526.6 Design for Manufacture .................................................................. 1566.7 LUCAS Design for Manufacturing Analysis and Evaluation Method .................................................................... 1576.8 Case Study: DFM Analysis Radiator Structure Front-End Support ............................................................ 1596.9 Case Study: Automotive Recliner Mechanism

(Based on the Work Done by DiCicco et al 2003) ........................... 1616.10 Introduction ...................................................................................... 161

6.10.1 Seat Recliner Subsystem History ....................................... 1616.10.2 Problem Statement ............................................................. 162

6.11 Competitive Benchmarking Study ................................................... 1636.12 Customer Functional Requirements ................................................. 163

6.12.1 Customer Needs ................................................................. 1636.12.2 Functional Requirements ................................................... 1656.12.3 FAST Diagram ................................................................... 1656.12.4 Affinity Diagram ................................................................ 1666.12.5 Product/Concept Integration .............................................. 166

6.13 Conceptual Designs Analysis and Comparisons .............................. 1686.13.1 Current Design ................................................................... 1686.13.2 Pivot-Pawl Combinations .................................................. 170

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6.13.3 Clip Design ........................................................................ 1706.13.4 Latch Design ...................................................................... 173

6.14 Conclusion and Discussions ............................................................ 1736.15 Summary .......................................................................................... 1796.16 Review Questions ............................................................................ 182References ................................................................................................... 183

Part II CAD/CAM and Features-Based Technologies

7 Computer-Based Design and Manufacturing ......................................... 1877.1 Introduction ...................................................................................... 187

7.1.1 Computer-Aided Design .................................................... 188 7.1.2 Computer-Aided Manufacturing ........................................ 188

7.2 Computer-Aided Design and Computer-Aided Manufacturing Integration ............................................................... 1887.3 Computer-Integrated Manufacturing ............................................... 189

7.3.1 The Role of CAD/CAM in Manufacturing ........................ 1917.4 Flexible Manufacturing Systems ..................................................... 1937.5 Concurrent Engineering ................................................................... 1937.6 Feature-Based Technologies ............................................................ 194

7.6.1 Types of Features ............................................................... 1957.7 Summary .......................................................................................... 1967.8 Review Questions ............................................................................ 196References ................................................................................................. 197

8 Feature Representations ........................................................................... 1998.1 Feature Definitions ........................................................................... 1998.2 Features in Manufacturing ............................................................... 200

8.2.1 Process Planning ................................................................ 201 8.2.2 Assembly Planning ............................................................ 202 8.2.3 Inspection Planning ............................................................ 203

8.3 Geometric Data Format .................................................................... 203 8.3.1 Wireframe Modeling .......................................................... 204 8.3.2 Surface Modeling ............................................................... 205 8.3.3 Solid Modeling ................................................................... 208

8.4 Boundary Representation ................................................................. 213 8.4.1 Euler’s Formula .................................................................. 214

8.5 Constructive Solid Geometry ........................................................... 2158.6 Advantages and Disadvantages of Constructive Solid Geometry and Boundary Representation ................................ 2178.7 Feature Recognition and Design ...................................................... 217

8.7.1 Feature-Based Design ........................................................ 218 8.7.2 Feature Interactions ............................................................ 219

8.8 Summary .......................................................................................... 2208.9 Review Questions ............................................................................ 221References ................................................................................................. 223

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9 Feature Extraction Techniques .............................................................. 2279.1 Feature Representation ..................................................................... 227

9.1.1 Feature Representation by B-rep ........................................ 228 9.1.2 Feature Representation by CSG ......................................... 229 9.1.3 Feature Representation by B-rep and CSG

(Hybrid Method)................................................................. 2309.2 Feature Recognition Techniques ...................................................... 231

9.2.1 The Syntactic Pattern Recognition Approach .................... 231 9.2.2 The Logic-Based Approach ................................................ 232 9.2.3 Graph-Based Approach ...................................................... 234 9.2.4 Expert System Approach .................................................... 237 9.2.5 Volume Decomposition and Composition Approach ......... 241 9.2.6 3D Feature Recognition from a 2D Feature Approach ......... 243

9.3 Intelligent Feature Recognition Methodology ................................. 2479.4 Conversion of CAD Data Files to OODS ........................................ 248

9.4.1 Basic IGES Entities ............................................................ 2489.5 The Overall OODS of the Proposed Methodology .......................... 2529.6 Geometry and Topology of B-rep .................................................... 256

9.6.1 Classification of Edges ....................................................... 257 9.6.2 Classification of Loops ....................................................... 258

9.7 Data Fields for Proposed Data Structure ......................................... 2599.8 Algorithms for Extracting Geometric Entities from CAD File ................................................................................. 261

9.8.1 Algorithm for Extracting Entries from Directory and Parameter Sections ...................................... 261

9.8.2 Algorithm for Extracting the Basic Entities of the Designed Part ........................................................... 262

9.9 Extracting Form Features from CAD Files ...................................... 264 9.9.1 An Example for Finding the Concave

Edge/Faces.......................................................................... 271 9.9.2 Algorithm for Determination

of the Concavity of the Edge .............................................. 272 9.9.3 Algorithm for Determination

of the Concavity of the Loop .............................................. 273 9.9.4 Algorithms for Feature Extraction (Production Rules) ...... 275

9.10 Summary .......................................................................................... 2879.11 Review Questions ............................................................................ 288References ................................................................................................... 289

Part III Rapid Design and Manufacturing

10 Engineering Materials: An Overview .................................................... 29510.1 Introduction ...................................................................................... 295

10.1.1 Materials in Engineering Applications ............................... 29510.1.2 Atomic Bonding and Crystalline Structure ........................ 296

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10.2 Mechanical Properties .................................................................... 29910.2.1 Stress–Strain Relationship ............................................... 30010.2.2 Other Properties ............................................................... 30110.2.3 Hardness ........................................................................... 301

10.3 Nanomaterial .................................................................................. 30110.3.1 Carbon-Based Nanomaterials and Applications .............. 30210.3.2 Carbon Nanotube Manufacturing .................................... 305

10.4 Purification of Thin Films .............................................................. 30810.5 Challenges and Limitations ............................................................ 30910.6 Summary ........................................................................................ 31010.7 Review Questions .......................................................................... 311References ................................................................................................. 311

11 Geometric Dimensioning and Tolerancing ........................................... 31311.1 Introduction .................................................................................... 31311.2 GD&T Definition and Standard ..................................................... 31411.3 GD&T Terminologies .................................................................... 315

11.3.1 Functional Dimensioning ................................................. 31511.3.2 Basic Dimensioning ......................................................... 31611.3.3 ASME Y14.5M-1994 Fundamental

rules of GD&T ................................................................. 31611.4 Engineering Tolerance ................................................................... 31711.5 Geometric Characteristic Symbols ................................................ 322

11.5.1 Form Controls .................................................................. 32211.5.2 Profile Control ................................................................. 32911.5.3 Orientation ....................................................................... 33011.5.4 Location ........................................................................... 33211.5.5 Runout .............................................................................. 333

11.6 Manufacturing Processes and Tolerances ...................................... 33411.7 Summary ........................................................................................ 33511.8 Review Questions .......................................................................... 337References ................................................................................................. 337

12 Rapid Prototyping ................................................................................... 33912.1 Introduction .................................................................................... 33912.2 Benefits of Rapid Prototyping Technology .................................... 34012.3 Rapid Prototyping Terminology ..................................................... 34112.4 Rapid Prototyping Systems ............................................................ 343

12.4.1 Stereolithography ............................................................. 34312.4.2 Solid Ground Curing ........................................................ 34512.4.3 Laminated Object Manufacturing .................................... 34712.4.4 Selective Laser Sintering ................................................. 34812.4.5 Direct Shell Production Casting....................................... 35012.4.6 Fused Deposition Modeling ............................................. 352

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12.5 Summary ........................................................................................ 35312.6 Review Questions .......................................................................... 353References ................................................................................................. 353

13 Data Mining Methodology and Techniques .......................................... 35513.1 Introduction .................................................................................... 35513.2 Data Mining ................................................................................... 35613.3 The Methodology ........................................................................... 357

13.3.1 Problem Definition........................................................... 35813.3.2 Acquisition of Background Knowledge........................... 35913.3.3 Selection of Data .............................................................. 36013.3.4 Pre-processing of Data ..................................................... 36013.3.5 Analysis and Interpretation .............................................. 36113.3.6 Reporting and Use............................................................ 361

13.4 Data Mining Techniques ................................................................ 36213.4.1 Traditional Methods of Data Mining ............................... 36213.4.2 Modern Methods of Data Mining .................................... 363

13.5 Genetic Algorithm .......................................................................... 36613.6 GA Methodology ........................................................................... 367

13.6.1 Genetic Algorithms .......................................................... 36813.6.2 Genetic Operations........................................................... 37113.6.3 Searching in Genetic Algorithms ..................................... 37513.6.4 Encoding Problems .......................................................... 37613.6.5 Selection ........................................................................... 376

13.7 Summary ........................................................................................ 37913.8 Review Questions .......................................................................... 379References ................................................................................................. 379

14 Group Technology and Applications ..................................................... 38314.1 Introduction .................................................................................... 38314.2 Traditional Manufacturing Systems: An Overview ....................... 38414.3 Group Technology .......................................................................... 385

14.3.1 Hierarchical (Monocode) Structure ................................. 38614.3.2 Chain (Attribute or Polycode) Structure .......................... 38714.3.3 Hybrid Structure............................................................... 387

14.4 Sorting Techniques ......................................................................... 38814.4.1 Rank Order Clustering Algorithm .................................... 38914.4.2 Modified Rank Order Clustering Algorithm .................... 39114.4.3 Bond Energy Algorithm ................................................... 39114.4.4 Cluster Identification Algorithm ...................................... 39214.4.5 Extended Cluster Identification Algorithm ...................... 39514.4.6 Similarity Coefficient-Based Clustering .......................... 39514.4.7 Mathematical Programming-Based Clustering ................ 396

14.5 Cellular Manufacturing Systems and Design ................................ 39914.5.1 The Methodology for Forming Machine Cells ................ 401

xxvContents

14.6 Process Planning and Computer-Aided Process Planning Systems .............................................................. 41814.6.1 Critical Issues in the Design of CAPP Systems ............... 42014.6.2 Structure for a Template-Based System ........................... 422

14.7 Summary ........................................................................................ 43014.8 Review Questions .......................................................................... 430Appendix A: Formulation Used for Material Removal of Crankshaft ...................................................................... 431Appendix B: Sample Process plan ......................................................... 432References ................................................................................................. 435

Index ................................................................................................................. 439