Part 1 Basics 2
1 Introduction to Mechanical Engineering Design 3
1-1 Design 4
1-2 Mechanical Engineering Design 5
1-3 Phases and Interactions of the Design Process 5
1-4 Design Tools and Resources 8
1-5 The Design Engineer’s Professional Responsibilities 10
1-6 Standards and Codes 12
1-7 Economics 12
1-8 Safety and Product Liability 15
1-9 Stress and Strength 15
1-10 Uncertainty 16
1-11 Design Factor and Factor of Safety 17
1-12 Reliability 18
1-13 Dimensions and Tolerances 19
1-14 Units 21
1-15 Calculations and Significant Figures 22
1-16 Power Transmission Case Study Specifications 23
Problems 24
2 Materials 27
2-1 Material Strength and Stiffness 28
2-2 The Statistical Significance of Material Properties 32
2-3 Strength and Cold Work 33
2-4 Hardness 36
2-5 Impact Properties 37
2-6 Temperature Effects 39
2-7 Numbering Systems 40
2-8 Sand Casting 41
2-9 Shell Molding 42
2-10 Investment Casting 42
2-11 Powder-Metallurgy Process 42
2-12 Hot-Working Processes 43
2-13 Cold-Working Processes 44
2-14 The Heat Treatment of Steel 44
2-15 Alloy Steels 47
2-16 Corrosion-Resistant Steels 48
2-17 Casting Materials 49
2-18 Nonferrous Metals 51
2-19 Plastics 54
2-20 Composite Materials 55
2-21 Materials Selection 56
Problems 63
3 Load and Stress Analysis 67
3-1 Equilibrium and Free-Body Diagrams 68
3-2 Shear Force and Bending Moments in Beams 71
3-3 Singularity Functions 73
3-4 Stress 75
3-5 Cartesian Stress Components 75
3-6 Mohr’s Circle for Plane Stress 76
3-7 General Three-Dimensional Stress 82
3-8 Elastic Strain 83
3-9 Uniformly Distributed Stresses 84
3-10 Normal Stresses for Beams in Bending 85
3-11 Shear Stresses for Beams in Bending 90
3-12 Torsion 95
3-13 Stress Concentration 105
3-14 Stresses in Pressurized Cylinders 107
3-15 Stresses in Rotating Rings 110
3-16 Press and Shrink Fits 110
3-17 Temperature Effects 111
3-18 Curved Beams in Bending 112
3-19 Contact Stresses 117
3-20 Summary 121
Problems 121
4 Deflection and Stiffness 141
4-1 Spring Rates 142
4-2 Tension，Compression，and Torsion 143
4-3 Deflection Due to Bending 144
4-4 Beam Deflection Methods 146
4-5 Beam Deflections by Superposition 147
4-6 Beam Deflections by Singularity Functions 150
4-7 Strain Energy 156
4-8 Castigliano’s Theorem 158
4-9 Deflection of Curved Members 163
4-10 Statically Indeterminate Problems 168
4-11 Compression Members——General 173
4-12 Long Columns with Central Loading 173
4-13 Intermediate-Length Columns with Central Loading 176
4-14 Columns with Eccentric Loading 176
4-15 Struts or Short Compression Members 180
4-16 Elastic Stability 182
4-17 Shock and Impact 183
4-18 Suddenly Applied Loading 184
Problems 186
Part 2 Failure Prevention 204
5 Failures Resulting from Static Loading 205
5-1 Static Strength 208
5-2 Stress Concentration 209
5-3 Failure Theories 211
5-4 Maximum-Shear-Stress Theory for Ductile Materials 211
5-5 Distortion-Energy Theory for Ductile Materials 213
5-6 Coulomb-Mohr Theory for Ductile Materials 219
5-7 Failure of Ductile Materials Summary 222
5-8 Maximum-Normal-Stress Theory for Brittle Materials 226
5-9 Modifications of the Mohr Theory for Brittle Materials 227
5-10 Failure of Brittle Materials Summary 229
5-11 Selection of Failure Criteria 230
5-12 Introduction to Fracture Mechanics 231
5-13 Stochastic Analysis 240
5-14 Important Design Equations 246
Problems 248
6 Fatigue Failure Resulting from Variable Loading 257
6-1 Introduction to Fatigue in Metals 258
6-2 Approach to Fatigue Failure in Analysis and Design 264
6-3 Fatigue-Life Methods 265
6-4 The Stress-Life Method 265
6-5 The Strain-Life Method 268
6-6 The Linear-Elastic Fracture Mechanics Method 270
6-7 The Endurance Limit 274
6-8 Fatigue Strength 275
6-9 Endurance Limit Modifying Factors 278
6-10 Stress Concentration and Notch Sensitivity 287
6-11 Characterizing Fluctuating Stresses 292
6-12 Fatigue Failure Criteria for Fluctuating Stress 295
6-13 Torsional Fatigue Strength under Fluctuating Stresses 309
6-14 Combinations of Loading Modes 309
6-15 Varying，Fluctuating Stresses； Cumulative Fatigue Damage 313
6-16 Surface Fatigue Strength 319
6-17 Stochastic Analysis 322
6-18 Roadmaps and Important Design Equations for the Stress-Life Method 336
Problems 340
Part 3 Design of Mechanical Elements 346
7 Shafts and Shaft Components 347
7-1 Introduction 348
7-2 Shaft Materials 348
7-3 Shaft layout 349
7-4 Shaft Design for Stress 354
7-5 Deflection Considerations 367
7-6 Critical Speeds for Shafts 371
7-7 Miscellaneous Shaft Components 376
7-8 Limits and Fits 383
Problems 388
8 Screws，Fasteners，and the Design of Nonpermanent Joints 395
8-1 Thread Standards and Definitions 396
8-2 The Mechanics of Power Screws 400
8-3 Threaded Fasteners 408
8-4 Joints——Fastener Stiffness 410
8-5 Joints——Member Stiffness 413
8-6 Bolt Strength 417
8-7 Tension Joints——The External Load 421
8-8 Relating Bolt Torque to Bolt Tension 422
8-9 Statically Loaded Tension Joint with Preload 425
8-10 Gasketed Joints 429
8-11 Fatigue Loading of Tension Joints 429
8-12 Bolted and Riveted Joints Loaded in Shear 435
Problems 443
9 Welding，Bonding，and the Design of Permanent Joints 457
9-1 Welding Symbols 458
9-2 Butt and Fillet Welds 460
9-3 Stresses in Welded Joints in Torsion 464
9-4 Stresses in Welded Joints in Bending 469
9-5 The Strength of Welded Joints 471
9-6 Static Loading 474
9-7 Fatigue Loading 478
9-8 Resistance Welding 480
9-9 Adhesive Bonding 480
Problems 489
10 Mechanical Springs 499
10-1 Stresses in Helical Springs 500
10-2 The Curvature Effect 501
10-3 Deflection of Helical Springs 502
10-4 Compression Springs 502
10-5 Stability 504
10-6 Spring Materials 505
10-7 Helical Compression Spring Design for Static Service 510
10-8 Critical Frequency of Helical Springs 516
10-9 Fatigue Loading of Helical Compression Springs 518
10-10 Helical Compression Spring Design for Fatigue Loading 521
10-11 Extension Springs 524
10-12 Helical Coil Torsion Springs 532
10-13 Belleville Springs 539
10-14 Miscellaneous Springs 540
10-15 Summary 542
Problems 542
11 Rolling-Contact Bearings 549
11-1 Bearing Types 550
11-2 Bearing Life 553
11-3 Bearing Load Life at Rated Reliability 554
11-4 Bearing Survival：Reliability versus Life 555
11-5 Relating Load，Life，and Reliability 557
11-6 Combined Radial and Thrust Loading 559
11-7 Variable Loading 564
11-8 Selection of Ball and Cylindrical Roller Bearings 568
11-9 Selection of Tapered Roller Bearings 571
11-10 Design Assessment for Selected Rolling-Contact Bearings 582
11-11 Lubrication 586
11-12 Mounting and Enclosure 587
Problems 591
12 Lubrication and Journal Bearings 597
12-1 Types of Lubrication 598
12-2 Viscosity 599
12-3 Petroff’s Equation 601
12-4 Stable Lubrication 603
12-5 Thick-Film Lubrication 604
12-6 Hydrodynamic Theory 605
12-7 Design Considerations 609
12-8 The Relations of the Variables 611
12-9 Steady-State Conditions in Self-Contained Bearings 625
12-10 Clearance 628
12-11 Pressure-Fed Bearings 630
12-12 Loads and Materials 636
12-13 Bearing Types 638
12-14 Thrust Bearings 639
12-15 Boundary-Lubricated Bearings 640
Problems 649
13 Gears—General 653
13-1 Types of Gear 654
13-2 Nomenclature 655
13-3 Conjugate Action 657
13-4 Involute Properties 658
13-5 Fundamentals 658
13-6 Contact Ratio 664
13-7 Interference 665
13-8 The Forming of Gear Teeth 667
13-9 Straight Bevel Gears 670
13-10 Parallel Helical Gears 671
13-11 Worm Gears 675
13-12 Tooth Systems 676
13-13 Gear Trains 678
13-14 Force Analysis——Spur Gearing 685
13-15 Force Analysis——Bevel Gearing 689
13-16 Force Analysis——Helical Gearing 692
13-17 Force Analysis——Worm Gearing 694
Problems 700
14 Spur and Helical Gears 713
14-1 The Lewis Bending Equation 714
14-2 Surface Durability 723
14-3 AGMA Stress Equations 725
14-4 AGMA Strength Equations 727
14-5 Geometry Factors I and J（Z，and YJ） 731
14-6 The Elastic Coefficient Cp （ZE） 736
14-7 Dynamic Factor Kv 736
14-8 Overload Factor Ko 738
14-9 Surface Condition Factor Cf （ZR） 738
14-10 Size Factor Ks 739
14-11 Load-Distribution Factor Km（KH） 739
14-12 Hardness-Ratio Factor CH 741
14-13 Stress Cycle Life Factors YN and ZN 742
14-14 Reliability Factor KR （Yz） 743
14-15 Temperature Factor KT （Yθ） 744
14-16 Rim-Thickness Factor KB 744
14-17 Safety Factors SF and SH 745
14-18 Analysis 745
14-19 Design of a Gear Mesh 755
Problems 760
15 Bevel and Worm Gears 765
15-1 Bevel Gearing——General 766
15-2 Bevel-Gear Stresses and Strengths 768
15-3 AGMA Equation Factors 771
15-4 Straight-Bevel Gear Analysis 783
15-5 Design of a Straight-Bevel Gear Mesh 786
15-6 Worm Gearing——AGMA Equation 789
15-7 Worm-Gear Analysis 793
15-8 Designing a Worm-Gear Mesh 797
15-9 Buckingham Wear Load 800
Problems 801
16 Clutches，Brakes，Couplings，and Flywheels 805
16-1 Static Analysis of Clutches and Brakes 807
16-2 Internal Expanding Rim Clutches and Brakes 812
16-3 External Contracting Rim Clutches and Brakes 820
16-4 Band-Type Clutches and Brakes 824
16-5 Frictional-Contact Axial Clutches 825
16-6 Disk Brakes 829
16-7 Cone Clutches and Brakes 833
16-8 Energy Considerations 836
16-9 Temperature Rise 837
16-10 Friction Materials 841
16-11 Miscellaneous Clutches and Couplings 844
16-12 Flywheels 846
Problems 851
17 Flexible Mechanical Elements 859
17-1 Belts 860
17-2 Flat- and Round-Belt Drives 863
17-3 V Belts 878
17-4 Timing Belts 886
17-5 Roller Chain 887
17-6 Wire Rope 896
17-7 Flexible Shafts 904
Problems 905
18 Power Transmission Case Study 913
18-1 Design Sequence for Power Transmission 915
18-2 Power and Torque Requirements 916
18-3 Gear Specification 916
18-4 Shaft Layout 923
18-5 Force Analysis 925
18-6 Shaft Material Selection 925
18-7 Shaft Design for Stress 926
18-8 Shaft Design for Deflection 926
18-9 Bearing Selection 927
18-11 Key and Retaining Ring Selection 928
18-12 Final Analysis 931
Problems 931
Part 4 Analysis Tools 932
19 Finite-Element Analysis 933
19-1 The Finite-Element Method 935
19-2 Element Geometries 937
19-3 The Finite-Element Solution Process 939
19-4 Mesh Generation 942
19-5 Load Application 944
19-6 Boundary Conditions 945
19-7 Modeling Techniques 946
19-8 Thermal Stresses 949
19-9 Critical Buckling Load 949
19-10 Vibration Analysis 951
19-11 Summary 952
Problems 954
20 Statistical Considerations 957
20-1 Random Variables 958
20-2 Arithmetic Mean，Variance，and Standard Deviation 960
20-3 Probability Distributions 965
20-4 Propagation of Error 972
20-5 Linear Regression 974
Problems 977
Appendices 983
A Useful Tables 983
B Answers to Selected Problems 1039
Index 1044