Shigley's mechanical engineering design

Cover......Page 1
Title Page......Page 6
Copyright......Page 7
Contents......Page 13
Preface......Page 18
Part 1 Basics......Page 27
1 Introduction to Mechanical Engineering Design......Page 28
1–1 Design......Page 29
1–3 Phases and Interactions of the Design Process......Page 30
1–4 Design Tools and Resources......Page 33
1–5 The Design Engineer’s Professional Responsibilities......Page 35
1–7 Economics......Page 37
1–9 Stress and Strength......Page 40
1–10 Uncertainty......Page 41
1–11 Design Factor and Factor of Safety......Page 42
1–12 Reliability......Page 43
1–13 Dimensions and Tolerances......Page 44
1–14 Units......Page 46
1–15 Calculations and Significant Figures......Page 47
1–16 Design Topic Interdependencies......Page 48
1–17 Power Transmission Case Study Specifications......Page 49
Problems......Page 51
2 Materials......Page 56
2–1 Material Strength and Stiffness......Page 57
2–2 The Statistical Significance of Material Properties......Page 61
2–3 Strength and Cold Work......Page 63
2–4 Hardness......Page 66
2–5 Impact Properties......Page 67
2–6 Temperature Effects......Page 68
2–7 Numbering Systems......Page 70
2–8 Sand Casting......Page 71
2–12 Hot-Working Processes......Page 72
2–13 Cold-Working Processes......Page 73
2–14 The Heat Treatment of Steel......Page 74
2–15 Alloy Steels......Page 77
2–16 Corrosion-Resistant Steels......Page 78
2–17 Casting Materials......Page 79
2–18 Nonferrous Metals......Page 80
2–19 Plastics......Page 83
2–20 Composite Materials......Page 85
2–21 Materials Selection......Page 86
Problems......Page 92
3 Load and Stress Analysis......Page 96
3–1 Equilibrium and Free-Body Diagrams......Page 97
3–2 Shear Force and Bending Moments in Beams......Page 100
3–3 Singularity Functions......Page 102
3–5 Cartesian Stress Components......Page 104
3–6 Mohr’s Circle for Plane Stress......Page 105
3–7 General Three-Dimensional Stress......Page 111
3–8 Elastic Strain......Page 112
3–9 Uniformly Distributed Stresses......Page 113
3–10 Normal Stresses for Beams in Bending......Page 114
3–11 Shear Stresses for Beams in Bending......Page 119
3–12 Torsion......Page 126
3–13 Stress Concentration......Page 135
3–14 Stresses in Pressurized Cylinders......Page 138
3–15 Stresses in Rotating Rings......Page 140
3–16 Press and Shrink Fits......Page 141
3–17 Temperature Effects......Page 142
3–18 Curved Beams in Bending......Page 143
3–19 Contact Stresses......Page 147
3–20 Summary......Page 151
Problems......Page 152
4 Deflection and Stiffness......Page 172
4–1 Spring Rates......Page 173
4–2 Tension, Compression, and Torsion......Page 174
4–3 Deflection Due to Bending......Page 175
4–4 Beam Deflection Methods......Page 177
4–5 Beam Deflections by Superposition......Page 178
4–6 Beam Deflections by Singularity Functions......Page 181
4–7 Strain Energy......Page 187
4–8 Castigliano’s Theorem......Page 189
4–9 Deflection of Curved Members......Page 194
4–10 Statically Indeterminate Problems......Page 200
4–12 Long Columns with Central Loading......Page 206
4–14 Columns with Eccentric Loading......Page 209
4–15 Struts or Short Compression Members......Page 213
4–16 Elastic Stability......Page 215
4–17 Shock and Impact......Page 216
Problems......Page 217
Part 2 Failure Prevention......Page 237
5 Failures Resulting from Static Loading......Page 238
5–1 Static Strength......Page 241
5–2 Stress Concentration......Page 242
5–4 Maximum-Shear-Stress Theory for Ductile Materials......Page 244
5–5 Distortion-Energy Theory for Ductile Materials......Page 246
5–6 Coulomb-Mohr Theory for Ductile Materials......Page 253
5–7 Failure of Ductile Materials Summary......Page 256
5–9 Modifications of the Mohr Theory for Brittle Materials......Page 260
5–11 Selection of Failure Criteria......Page 263
5–12 Introduction to Fracture Mechanics......Page 264
5–13 Stochastic Analysis......Page 273
5–14 Important Design Equations......Page 279
Problems......Page 281
6 Fatigue Failure Resulting from Variable Loading......Page 290
6–1 Introduction to Fatigue in Metals......Page 291
6–2 Approach to Fatigue Failure in Analysis and Design......Page 297
6–4 The Stress-Life Method......Page 298
6–5 The Strain-Life Method......Page 301
6–6 The Linear-Elastic Fracture Mechanics Method......Page 303
6–7 The Endurance Limit......Page 307
6–8 Fatigue Strength......Page 308
6–9 Endurance Limit Modifying Factors......Page 311
6–10 Stress Concentration and Notch Sensitivity......Page 320
6–11 Characterizing Fluctuating Stresses......Page 325
6–12 Fatigue Failure Criteria for Fluctuating Stress......Page 328
6–14 Combinations of Loading Modes......Page 342
6–15 Varying, Fluctuating Stresses; Cumulative Fatigue Damage......Page 346
6–16 Surface Fatigue Strength......Page 352
6–17 Stochastic Analysis......Page 355
6–18 Road Maps and Important Design Equations for the Stress-Life Method......Page 369
Problems......Page 373
Part 3 Design of Mechanical Elements......Page 383
7 Shafts and Shaft Components......Page 384
7–2 Shaft Materials......Page 385
7–3 Shaft Layout......Page 386
7–4 Shaft Design for Stress......Page 391
7–5 Deflection Considerations......Page 404
7–6 Critical Speeds for Shafts......Page 408
7–7 Miscellaneous Shaft Components......Page 413
7–8 Limits and Fits......Page 420
Problems......Page 425
8 Screws, Fasteners, and the Design of Nonpermanent Joints......Page 434
8–1 Thread Standards and Definitions......Page 435
8–2 The Mechanics of Power Screws......Page 439
8–3 Threaded Fasteners......Page 447
8–4 Joints—Fastener Stiffness......Page 449
8–5 Joints—Member Stiffness......Page 452
8–6 Bolt Strength......Page 457
8–7 Tension Joints—The External Load......Page 460
8–8 Relating Bolt Torque to Bolt Tension......Page 462
8–9 Statically Loaded Tension Joint with Preload......Page 465
8–11 Fatigue Loading of Tension Joints......Page 469
8–12 Bolted and Riveted Joints Loaded in Shear......Page 476
Problems......Page 484
9 Welding, Bonding, and the Design of Permanent Joints......Page 500
9–1 Welding Symbols......Page 501
9–2 Butt and Fillet Welds......Page 503
9–3 Stresses in Welded Joints in Torsion......Page 507
9–4 Stresses in Welded Joints in Bending......Page 512
9–5 The Strength of Welded Joints......Page 514
9–6 Static Loading......Page 517
9–7 Fatigue Loading......Page 521
9–9 Adhesive Bonding......Page 523
Problems......Page 532
10 Mechanical Springs......Page 542
10–1 Stresses in Helical Springs......Page 543
10–2 The Curvature Effect......Page 544
10–4 Compression Springs......Page 545
10–5 Stability......Page 547
10–6 Spring Materials......Page 548
10–7 Helical Compression Spring Design for Static Service......Page 553
10–8 Critical Frequency of Helical Springs......Page 559
10–9 Fatigue Loading of Helical Compression Springs......Page 561
10–10 Helical Compression Spring Design for Fatigue Loading......Page 564
10–11 Extension Springs......Page 567
10–12 Helical Coil Torsion Springs......Page 575
10–13 Belleville Springs......Page 582
10–14 Miscellaneous Springs......Page 583
Problems......Page 585
11 Rolling-Contact Bearings......Page 594
11–1 Bearing Types......Page 595
11–2 Bearing Life......Page 598
11–3 Bearing Load Life at Rated Reliability......Page 599
11–4 Bearing Survival: Reliability versus Life......Page 601
11–5 Relating Load, Life, and Reliability......Page 602
11–6 Combined Radial and Thrust Loading......Page 604
11–7 Variable Loading......Page 609
11–8 Selection of Ball and Cylindrical Roller Bearings......Page 613
11–9 Selection of Tapered Roller Bearings......Page 615
11–10 Design Assessment for Selected Rolling-Contact Bearings......Page 624
11–11 Lubrication......Page 628
11–12 Mounting and Enclosure......Page 629
Problems......Page 633
12 Lubrication and Journal Bearings......Page 642
12–1 Types of Lubrication......Page 643
12–2 Viscosity......Page 644
12–3 Petroff’s Equation......Page 646
12–4 Stable Lubrication......Page 648
12–5 Thick-Film Lubrication......Page 649
12–6 Hydrodynamic Theory......Page 650
12–7 Design Considerations......Page 654
12–8 The Relations of the Variables......Page 656
12–9 Steady-State Conditions in Self-Contained Bearings......Page 670
12–10 Clearance......Page 673
12–11 Pressure-Fed Bearings......Page 675
12–12 Loads and Materials......Page 681
12–13 Bearing Types......Page 683
12–14 Thrust Bearings......Page 684
12–15 Boundary-Lubricated Bearings......Page 685
Problems......Page 694
13 Gears—General......Page 698
13–1 Types of Gear......Page 699
13–2 Nomenclature......Page 700
13–3 Conjugate Action......Page 702
13–5 Fundamentals......Page 703
13–6 Contact Ratio......Page 709
13–7 Interference......Page 710
13–8 The Forming of Gear Teeth......Page 712
13–9 Straight Bevel Gears......Page 715
13–10 Parallel Helical Gears......Page 716
13–11 Worm Gears......Page 720
13–12 Tooth Systems......Page 721
13–13 Gear Trains......Page 723
13–14 Force Analysis—Spur Gearing......Page 730
13–15 Force Analysis—Bevel Gearing......Page 734
13–16 Force Analysis—Helical Gearing......Page 737
13–17 Force Analysis—Worm Gearing......Page 739
Problems......Page 745
14 Spur and Helical Gears......Page 758
14–1 The Lewis Bending Equation......Page 759
14–2 Surface Durability......Page 768
14–3 AGMA Stress Equations......Page 770
14–4 AGMA Strength Equations......Page 772
14–5 Geometry Factors I and J (Z[sub(I)] and Y[sub(j)])......Page 776
14–7 Dynamic Factor K[sub(v)]......Page 781
14–9 Surface Condition Factor C[sub(f)] (Z[sub(R)])......Page 783
14–11 Load-Distribution Factor K[sub(m)] (K[sub(H)])......Page 784
14–12 Hardness-Ratio Factor C[sub(H)]......Page 786
14–13 Stress Cycle Life Factors Y[sub(N)] and Z[sub(N)]......Page 787
14–14 Reliability Factor K[sub(R) (Y[sub(Z)])......Page 788
14–16 Rim-Thickness Factor K[sub(B)]......Page 789
14–18 Analysis......Page 790
14–19 Design of a Gear Mesh......Page 800
Problems......Page 805
15 Bevel and Worm Gears......Page 810
15–1 Bevel Gearing—General......Page 811
15–2 Bevel-Gear Stresses and Strengths......Page 813
15–3 AGMA Equation Factors......Page 816
15–4 Straight-Bevel Gear Analysis......Page 828
15–5 Design of a Straight-Bevel Gear Mesh......Page 831
15–6 Worm Gearing—AGMA Equation......Page 834
15–7 Worm-Gear Analysis......Page 838
15–8 Designing a Worm-Gear Mesh......Page 842
15–9 Buckingham Wear Load......Page 845
Problems......Page 846
16 Clutches, Brakes, Couplings, and Flywheels......Page 850
16–1 Static Analysis of Clutches and Brakes......Page 852
16–2 Internal Expanding Rim Clutches and Brakes......Page 857
16–3 External Contracting Rim Clutches and Brakes......Page 865
16–4 Band-Type Clutches and Brakes......Page 869
16–5 Frictional-Contact Axial Clutches......Page 870
16–6 Disk Brakes......Page 874
16–7 Cone Clutches and Brakes......Page 878
16–8 Energy Considerations......Page 881
16–9 Temperature Rise......Page 882
16–10 Friction Materials......Page 886
16–11 Miscellaneous Clutches and Couplings......Page 889
16–12 Flywheels......Page 891
Problems......Page 896
17 Flexible Mechanical Elements......Page 904
17–1 Belts......Page 905
17–2 Flat- and Round-Belt Drives......Page 908
17–3 V Belts......Page 923
17–4 Timing Belts......Page 931
17–5 Roller Chain......Page 932
17–6 Wire Rope......Page 941
17–7 Flexible Shafts......Page 949
Problems......Page 950
18 Power Transmission Case Study......Page 958
18–1 Design Sequence for Power Transmission......Page 960
18–3 Gear Specification......Page 961
18–4 Shaft Layout......Page 968
18–6 Shaft Material Selection......Page 970
18–8 Shaft Design for Deflection......Page 971
18–9 Bearing Selection......Page 972
18–11 Key and Retaining Ring Selection......Page 973
Problems......Page 976
Part 4 Analysis Tools......Page 977
19 Finite-Element Analysis......Page 978
19–1 The Finite-Element Method......Page 980
19–2 Element Geometries......Page 982
19–3 The Finite-Element Solution Process......Page 984
19–4 Mesh Generation......Page 987
19–5 Load Application......Page 989
19–6 Boundary Conditions......Page 990
19–7 Modeling Techniques......Page 991
19–9 Critical Buckling Load......Page 994
19–10 Vibration Analysis......Page 996
19–11 Summary......Page 997
Problems......Page 999
20 Statistical Considerations......Page 1002
20–1 Random Variables......Page 1003
20–2 Arithmetic Mean, Variance, and Standard Deviation......Page 1005
20–3 Probability Distributions......Page 1010
20–4 Propagation of Error......Page 1017
20–5 Linear Regression......Page 1019
Problems......Page 1022
A: Useful Tables......Page 1028
B: Answers to Selected Problems......Page 1084
Index......Page 1090