FOURTH E D I T I O N Fundamentals of Machine Component Design ROBERT C. JUVINALL Professor of Mechanical Engineering University of Michigan KURT M. MARSHEK Professor of Mechanical Engineering University of Texas at Austin WILEY JOHN WILEY & SONS, INC.
PART 1 FUNDAMENTALS, 1 Chapter 1 A Broad Perspective of Mechanical Engineering Design, 3 1.1 An Overview of the Subject, 3 1.2 Safety Considerations, 4 1.3 Ecological Considerations, 10 1.4 Societal Considerations, 12 1.5 Overall Design Considerations, 14 1.6 Systems of Units, 15 1.7 Methodology for Solving Machine Component Problems, 19 1.8 Work and Energy, 21 1.9 Power, 23 1.10 Conservation of Energy, 24 Chapter 2 Force Analysis, 39 2.1 Introduction, 39 2.2 Equilibrium Equations and Free-Body Diagrams, 39 2.3 Beam Loading, 51 2.4 Locating Critical Sections Force Flow Concept, 54 2.5 Load Division Between Redundant Supports, 56 2.6 Force Flow Concept Applied to Redundant Ductile Structures, 58 Chapter 3 Materials Study, 79 3.1 Introduction, 79 3.2 The Static Tensile Test "Engineering" Stress-Strain Relationships, 80 3.3 Implications of the "Engineering" Stress-Strain Curve, 81 3.4 The Static Tensile Test "True" Stress-Strain Relationships, 84 3.5 Energy-Absorbing Capacity, 86 3.6 Estimating Strength Properties from Penetration Hardness Tests, 87 3.7 Use of "Handbook" Data for Material Strength Properties, 90 3.8 Machinability, 91 3.9 Cast Iron, 91 3.10 Steel, 92 3.11 Nonferrous Alloys, 95 3.12 Plastics, 96 3.13 Material Selection Charts, 101 3.14 Engineering Material Selection Process, 105 Chapter 4 Stresses Static Body, 117 4.1 Introduction, 117 4.2 Axial Loading, 117 4.3 Direct Shear Loading, 119 4.4 Torsional Loading, 121 4.5 Pure Bending Loading, Straight Beams, 123 4.6 Pure Bending Loading, Curved Beams, 124 4.7 Transverse Shear Loading in Beams, 130 4.8 Induced Stresses, Mohr Circle Representation, 136 4.9 Combined Stresses Mohr Circle Representation, 139 4.10 Stress Equations Related to Mohr's Circle, 142 4.11 Three-Dimensional Stresses, 144 4.12 Stress Concentration Factor, K, 145 4.13 Importance of Stress Concentration, 146 4.14 Residual Stresses Caused by Yielding Axial Loading, 151 4.15 Residual Stresses Caused by Yielding Bending and Torsional Loading, 155 4.16 Thermal Stresses, 157 4.17 Importance of Residual Stresses, 160 Chapter 5 Strain, Deflection, Stability, and Buckling, 174 5.1 Introduction, 174 5.2 Strain Definition, Measurement, and Mohr Circle Representation, 175 5.3 Analysis of Strain Equiangular Rosettes, 177 5.4 Analysis of Strain Rectangular Rosettes, 179 5.5 Elastic Stress-Strain Relationships and Three-Dimensional Mohr Circles, 182 5.6 Deflection and Spring Rate Simple Cases, 184 5.7 Beam Deflection, 186 5.8 Determining Elastic Deflections by Castigliano's Method, 189 5.9 Redundant Reactions by Castigliano's Method, 202 5.10 Euler Column Buckling Elastic Instability, 207 5.11 Effective Column Length for Various End Conditions, 209 5.12 Column Design Equations J. B. Johnson Parabola, 210 5.13 Eccentric Column Loading the Secant Formula, 214 5.14 Equivalent Column Stresses, 216 5.15 Other Types of Buckling, 216 5.16 Finite Element Analysis, 218 Chapter 6 Theories of Failure, Safety Factors, and Reliability, 227 6.1 Introduction, 227 6.2 Types of Failure, 229 6.3 Fracture Mechanics Basic Concepts, 230 6.4 Fracture Mechanics Applications, 232 6.5 The "Theory" of Static Failure Theories, 242 ix
6.6 Maximum-Normal-Stress Theory, 244 6.7 Maximum-Shear-Stress Theory, 244 6.8 Maximum-Distortion-Energy Theory (Maximum- Octahedral-Shear-Stress Theory), 245 6.9 Modified Mohr Theory, 248 6.10 Selection and Use of Failure Theories, 249 6.11 Safety Factors Concept and Definition, 251 6.12 Safety Factors Selection of a Numerical Value, 253 6.13 Reliability, 255 6.14 Normal Distributions, 257 6.15 Interference Theory of Reliability Prediction, 259 Chapter 7 Impact Loading, 267 7.1 Introduction, 267 7.2 Stress and Deflection Caused by Linear and Bending Impact, 269 7.3 Stress and Deflection Caused by Torsional Impact, 277 7.4 Effect of Stress Raisers on Impact Strength, 280 Chapter 8 Fatigue Loading, 290 8.1 Introduction, 290 8.2 Basic Concepts, 290 8.3 Standard Fatigue Strengths (S' n ) for Rotating Bending, 292 8.4 Fatigue Strengths for Reversed Bending and Reversed Axial Loading, 298 8.5 Fatigue Strength for Reversed Torsional Loading, 299 8.6 Fatigue Strength for Reversed Biaxial Loading, 300 8.7 Influence of Surface and Size on Fatigue Strength, 301 8.8 Summary of Estimated Fatigue Strengths for Completely Reversed Loading, 304 8.9 Effect of Mean Stress on Fatigue Strength, 304 8.10 Effect of Stress Concentration with Completely Reversed Fatigue Loading, 312 8.11 Effect of Stress Concentration with Mean Plus Alternating Loads, 315 8.12 Fatigue Life Prediction with Randomly Varying Loads, 322 8.13 Effect of Surface Treatments on the Fatigue Strength of a Part, 326 8.14 Mechanical Surface Treatments Shot Peening and Others, 328 8.15 Thermal and Chemical Surface-Hardening Treatments (Induction Hardening, Carburizing, and Others), 329 8.16 Fatigue Crack Growth, 329 8.17 General Approach for Fatigue Design, 334 Chapter 9 Surface Damage Causes, 348 9.1 Introduction, 348 9.2 Corrosion: Fundamentals, 348 9.3 Corrosion: Electrode and Electrolyte Heterogeneity, 352 9.4 Design for Corrosion Control, 354 9.5 Corrosion Plus Static Stress, 356 9.6 Corrosion Plus Cyclic Stress, 359 9.7 Cavitation Damage, 360 9.8 Types of Wear, 360 9.9 Adhesive Wear, 361 9.10 Abrasive Wear, 363 9.11 Fretting, 364 9.12 Analytical Approach to Wear, 365 9.13 Curved-Surface Contact Stresses, 368 9.14 Surface Fatigue Failures, 375 9.15 Closure, 376 PART 2 APPLICATIONS, 383 Chapter 10 Power Screws and Threaded Fasteners, 385 10.1 Introduction, 385 10.2 Thread Forms, Terminology, and Standards, 386 10.3 Power Screws, 391 10.4 Static Screw Stresses, 399 10.5 Threaded Fastener Types, 404 10.6 Fastener Materials and Methods of Manufacture, 406 10.7 Bolt Tightening and Initial Tension, 406 10.8 Thread Loosening and Thread Locking, 411 10.9 Bolt Tension with External Joint-Separating Force, 413 10.10 Bolt (or Screw) Selection for Static Loading, 418 10.11 Bolt (or Screw) Selection for Fatigue Loading: Fundamentals, 425 10.12 Bolt (or Screw) Selection for Fatigue Loading: Using Special Test Data, 432 10.13 Increasing Bolted-Joint Fatigue Strength, 435 Chapter 11 Joining Components and Methods, 446 11.1 Introduction, 446 11.2 Rivets, 446 11.3 Welding Processes, 448 11.4 Welded Joints Subjected to Static Axial and Direct Shear Loading, 452 11.5 Welded Joints Subjected to Static Torsional and Bending Loading, 455 11.6 Fatigue Considerations in Welded Joints, 460 11.7 Brazing and Soldering, 463 11.8 Adhesives, 463 Chapter 12 Various Springs, 469 12.1 Introduction, 469 12.2 Torsion Bar Springs, 469 12.3 Coil Spring Stress and Deflection Equations, 470 12.4 Stress and Strength Analysis for Helical Compression Springs Static Loading, 476 12.5 End Designs of Helical Compression Springs, 479 12.6 Buckling Analysis of Helical Compression Springs, 480 12.7 Design Procedure for Helical Compression Springs Static Loading, 481 12.8 Design of Helical Compression Springs for Fatigue Loading, 485 12.9 Helical Extension Springs, 493
12.10 12.11 12.12 Beam Springs (Including Leaf Springs), 494 Torsion Springs, 500 Miscellaneous Springs, 501 Chapter 13 Bearings: Lubrication and Sliding, 517 13.1 Types of Lubricants, 517 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13 13.14 13.15 13.16 Types of Sliding Bearings, 518 Types of Lubrication, 518 Basic Concepts of Hydrodynamic Lubrication, 519 Viscosity, 522 Temperature and Pressure Effects on Viscosity, 526 Petroff's Equation for Bearing Friction, 527 Hydrodynamic Lubrication Theory, 529 Design Charts for Hydrodynamic Bearings, 532 Lubricant Supply, 540 Heat Dissipation, and Equilibrium Oil Film Temperature, 542 Bearing Materials, 544 Hydrodynamic Bearing Design, 545 Boundary and Mixed-Film Lubrication, 551 Thrust Bearings, 553 Elastohydrodynamic Lubrication, 554 Chapter 14 Rolling-Element Bearings, 559 14.1 Comparison of Alternative Means for Supporting Rotating Shafts, 559 14.2 14.3 14.4 14.5 14.6 14.7 14.8 History of Rolling-Element Bearings, 563 Rolling-Element Bearing Types, 564 Design of Rolling-Element Bearings, 568 Fitting of Rolling-Element Bearings, 572 "Catalogue Information" for Rolling-Element Bearings, 573 Bearing Selection, 576 Mounting Bearings to Provide Properly for Thrust Load, 586 Chapter 15 Gears: Sour, 591 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8 15.9 15.10 15.11 15.12 15.13 Introduction and History, 591 Geometry and Nomenclature, 592 Interference and Contact Ratio, 601 Gear Force Analysis, 604 Gear-Tooth Strength, 608 Basic Analysis of Gear-Tooth-Bending Stress (Lewis Equation), 608 Refined Analysis of Gear-Tooth-Bending Strength: Basic Concepts, 610 Refined Analysis of Gear-Tooth-Bending Strength: Recommended Procedure, 612 Gear-Tooth Surface Durability Basic Concepts, 619 Gear-Tooth Surface Fatigue Analysis Recommended Procedure, 622 Spur Gear Design Procedures, 627 Gear Materials, 632 Gear Trains, 632 Chapter 16 Gears: Helical, Bevel, and Worm, 647 16.1 Introduction, 647 16.2 16.3 16.4 16.5 16.6 16.7 16.8 16.9 16.10 16.11 16.12 16.13 Helical-Gear Geometry and Nomenclature, 650 Helical-Gear Force Analysis, 653 Helical-Gear-Tooth-Bending and Surface Fatigue Strengths, 656 Crossed Helical Gears, 657 Bevel Gear Geometry and Nomenclature, 658 Bevel Gear Force Analysis, 660 Bevel-Gear-Tooth-Bending and Surface Fatigue Strengths, 662 Bevel Gear Trains; Differential Gears, 664 Worm Gear Geometry and Nomenclature, 666 Worm Gear Force and Efficiency Analysis, 668 Worm-Gear-Bending and Surface Fatigue Strengths, 673 Worm Gear Thermal Capacity, 675 Chapter 17 Shafts and Related Parts, 688 17.1 Introduction, 688 17.2 17.3 17.4 17.5 17.6 17.7 Provision for Shaft Bearings, 689 Mounting Parts onto Rotating Shafts, 689 Rotating-Shaft Dynamics, 692 Overall Shaft Design, 694 Keys, Pins, and Splines, 699 Couplings and Universal Joints, 701 Chapter 18 Brakes and Clutches, 712 18.1 Introduction, 712 18.2 18.3 18.4 18.5 18.6 18.7 18.8 18.9 18.10 Disk Clutches, 712 Disk Brakes, 718 Energy Absorption and Cooling, 719 Cone Clutches and Brakes, 721 Short-Shoe Drum Brakes, 722 Eternal Long-Shoe Drum Brakes, 726 Internal Long-Shoe Drum Brakes, 733 Band Brakes, 735 Materials, 738 Chapter 19 Various Machine Components, 748 19.1 Introduction, 748 19.2 19.3 19.4 19.5 19.6 19.7 19.8 19.9 Flat Belts, 749 V-Belts, 751 Toothed Belts, 755 Roller Chains, 755 Inverted-Tooth Chains, 758 History of Hydrodynamic Drives, 759 Fluid Couplings, 760 Hydrodynamic Torque Converters, 764 Appendix A Units, A-l A-la Conversion Factors for British Gravitational, English, and SI Units, A-l
XII Contents A-lb Conversion Factor Equalities Listed by Physical Quantity, A-2 A-2a Standard SI Prefixes, A-4 A-2b SI Units and Symbols, A-5 A-3 Suggested SI Prefixes for Stress Calculations, A-6 A-4 Suggested SI Prefixes for Linear-Deflection Calculations, A-6 A-5 Suggested SI Prefixes for Angular-Deflection Calculations, A-6 Appendix B Properties of Sections and Solids, A-7 B-la Properties of Sections, A-7 B-lb Dimensions and Properties of Steel Pipe and Tubing Sections, A-8 B-2 Mass and Mass Moments of Inertia of Homogeneous Solids, A-10 Appendix C Material Properties and Uses, A-11 C-l Physical Properties of Common Metals, A-11 C-2 Tensile Properties of Some Metals, A-12 C-3a Typical Mechanical Properties and Uses of Gray Cast Iron, A-13 C-3b Mechanical Properties and Typical Uses of Malleable C-3c Cast Iron, A-14 Average Mechanical Properties and Typical Uses of Ductile (Nodular) Iron, A-15 C-4a Mechanical Properties of Selected Carbon and Alloy Steels, A-l6 C-4b Typical Uses of Plain Carbon Steels, A-18 C-5a Properties of Some Water-Quenched and Tempered Steels, A-19 C-5b Properties of Some Oil-Quenched and Tempered Carbon C-5c Steels, A-20 Properties of Some Oil-Quenched and Tempered Alloy Steels, A-21 C-6 Effect of Mass on Strength Properties of Steel, A-22 C-7 Mechanical Properties of Some Carburizing Steels, A-23 C-8 Mechanical Properties of Some Wrought Stainless Steels, A-24 C-9 Mechanical Properties of Some Iron-Based Superalloys, A-25 C-10 Mechanical Properties, Characteristics, and Typical Uses of Some Wrought Aluminum Alloys, A-26 C-ll Tensile Properties, Characteristics, and Typical Uses of Some Cast-Aluminum Alloys, A-27 C-12 Temper Designations for Aluminum and Magnesium Alloys, A-28 C-13 Mechanical Properties of Some Copper Alloys, A-29 C-14 Mechanical Properties of Some Magnesium Alloys, A-30 C-15 Mechanical Properties of Some Nickel Alloys, A-31 C-16 Mechanical Properties of Some Wrought-Titanium Alloys, A-32 C-17 Mechanical Properties of Some Zinc Casting Alloys, A-33 C-18a Representative Mechanical Properties of Some Common Plastics, A-34 C-18b Properties of Some Common Glass-Reinforced and Unreinforced Thermoplastic Resins, A-35 C-l8c Typical Applications of Common Plastics, A-36 C-19 Material Classes and Selected Members of Each Class, A-37 C-20 Designer's Subset of Engineering Materials, A-38 C-21 Processing Methods Used Most Frequently with Different Materials, A-39 C-22 Joinability of Materials, A-40 C-23 Materials for Machine Components, A-41 C-24 Relations Between Failure Modes and Material Properties, A-43 Appendix D Shear, Moment, and Deflection Equations for Beams, A-44 D-1 Cantilever Beams, A-44 D-2 Simply Supported Beams, A-45 D-3 Beams with Fixed Ends, A-47 D-4 Program for Determining Elastic Deflections of Stepped Shafts, A-48 Appendix E Fits and Tolerances, A-52 E-l Fits and Tolerances for Holes and Shafts, A-52 Index 1-1