Design ............................................................................................................... 3
Machine Design
3
Machine
4
Iteration
5
1.2
A Design Process ............................................................................................. 5
1.3
Problem Formulation and Calculation .............................................................. 8
Definition Stage
8
Preliminary Design Stage
8
Detailed Design Stage
9
Documentation Stage
9
1.4
The Engineering Model ..................................................................................... 9
Estimation and First-Order Analysis
10
The Engineering Sketch
10
1.5
Computer-Aided Design and Engineering ...................................................... 11
Computer-Aided Design (CAD)
11
Computer-Aided Engineering (CAE)
14
Computational Accuracy
16
1.6
The Engineering Report .................................................................................. 16
1.7
Factors of Safety and Design Codes .............................................................. 16
Factor of Safety
17
Choosing a Safety Factor
18
Design and Safety Codes
19
1.8
Statistical Considerations ............................................................................. 20
1.9
Units ............................................................................................................... 21
1.10 Summary ....................................................................................................... 25
1.11 References ..................................................................................................... 26
1.12 Web References .............................................................................................. 27
1.13 Bibliography ................................................................................................... 27
1.14 Problems ........................................................................................................ 28
viii
MACHINE DESIGN -
An Integrated Approach
CHAPTER 2 MATERIALS AND PROCESSES _________________________________ 29
2.0
Introduction ...................................................................................................29
2.1
Material-Property Definitions .......................................................................... 29
The Tensile Test
31
Ductility and Brittleness
33
The Compression Test
35
The Bending Test
35
The Torsion Test
35
Fatigue Strength and Endurance Limit
37
Impact Resistance
38
Fracture Toughness
40
Creep and Temperature Effects
40
2.2
The Statistical Nature of Material Properties .................................................41
2.3
Homogeneity and Isotropy .............................................................................42
2.4
Hardness ........................................................................................................42
Heat Treatment
44
Surface (Case) Hardening
45
Heat Treating Nonferrous Materials
46
Mechanical Forming and Hardening
46
2.5
Coatings and Surface Treatments ..................................................................48
Galvanic Action
49
Electroplating
50
Electroless Plating
50
Anodizing
51
Plasma-Sprayed Coatings
51
Chemical Coatings
51
2.6
General Properties of Metals ...........................................................................52
Cast Iron
52
Cast Steels
53
Wrought Steels
53
Steel Numbering Systems
54
Aluminum
56
Titanium
58
Magnesium
59
Copper Alloys
59
2.7
General Properties of Nonmetals ....................................................................60
Polymers
60
Ceramics
62
Composites
62
2.8
Selecting Materials .........................................................................................63
2.9
Summary ........................................................................................................64
2.10 References ......................................................................................................68
2.11 Web References ..............................................................................................68
2.12 Bibliography ...................................................................................................68
2.13 Problems ........................................................................................................69
ix