Mechanical Design of Machine Elements and Machines
A Failure Prevention Perspective
Second Edition
Jack A. Collins, Henry R. Busby & George H. Staab
The Ohio State University
Contents
PART ONE ENGINEERING PRINCIPLES
ix
Chapter 1
Keystones of Design: Materials
Selection and Geometry Determination 1
1.1 Some Background Philosophy 1
1.2 The Product Design Team 2
1.3 Function and Form; Aesthetics and
Ergonomics 5
1.4 Concepts and Definition of Mechanical
Design 6
1.5 Design Safety Factor 7
1.6 Stages of Design 7
1.7 Steps in the Design Process 9
1.8 Fail Safe and Safe Life Design Concepts 9
1.9 The Virtues of simplicity 10
1.10 Lessons Learned Strategy 12
1.11 Machine Elements, Subassemblies, and
the Whole Machine 12
1.12 The Role of Codes and Standards in the
Design Process 13
1.13 Ethics in Engineering Design 13
1.14 Units 14
Chapter 2
The Failure Prevention Perspective 22
2.1 Role of Failure Prevention Analysis in
Mechanical Design 22
2.2 Failure Criteria 22
2.3 Modes of Mechanical Failure 23
2.4 Elastic Deformation, Yielding, and Ductile
Rupture 28
2.5 Elastic Instability and Buckling 34
Buckling of a Simple Pin-Jointed Mechanism 35
Buckling of a Pinned-End Column 36
Columns with Other End Constraints 38
Inelastic Behavior and Initially Crooked
Columns 39
Column Failure Prediction and Design
Considerations 40
Buckling of Elements Other Than Columns 43
2.6 Shock and Impact 46
Stress Wave Propagation Under Impact Loading
Conditions 46
Energy Method of Approximating Stress and
Deflection Under Impact Loading
Conditions 47
2.7 Creep and Stress Rupture 52
Predictions of Long-Term Creep Behavior 53
Creep under Uniaxial State of Stress 55
Cumulative Creep Prediction 57
2.8 Wear and Corrosion 59
Wear 59
Corrosion 64
2.9 Fretting, Fretting Fatigue, and Fretting
Wear 66
Fretting Fatigue 67
Fretting Wear 68
Minimizing or Preventing Fretting Damage 69
2.10 Failure Data and the Design Task 70
2.11 Failure Assessment and Retrospective
Design 70
2.12 The Role of Safety Factors; Reliability
Concepts 71
2.13 Selection and Use of a Design Safety
Factor 72
2.14 Determination of Existing Safety Factors
in a Completed Design: A Conceptual
Contrast 744.6 Stresses Caused by Curved Surfaces in
Contact 174
4.7 Load Sharing in Redundant Assemblies
and Structures 179
Machine Elements as Springs 180
4.8 Preloading Concepts 186
4.9 Residual Stresses 189
Estimating Residual Stress 190
4.10 Environmental Effects 194
Chapter 5
Failure Theories 205
5.1 Preliminary Discussions 205
5.2 Multiaxial States of Stress and Strain 205
Principal Stresses 205
Stress Cubic Equation 206
Mohr’s Circle Analogy for Stress 210
Strain Cubic Equation and Principal Strains 213
Mohr’s Circle Analogy for Strain 213
Elastic Stress-Strain Relationships
(Hooke’s Law) 214
5.3 Stress Concentration 215
Stress Concentration Effects 216
Multiple Notches 217
5.4 Combined Stress Theories of Failure 224
Maximum Normal Stress Theory
(Rankine’s Theory) 225
Maximum Shearing Stress Theory
(Tresca–Guest Theory) 226
Distortion Energy Theory
(Huber–von Mises–Hemcky Theory) 227
Failure Theory Selection 229
5.5 Brittle Fracture and Crack Propagation;
Linear Elastic Fracture Mechanics 233
5.6 Fluctuating Loads, Cumulative Damage,
and Fatigue Life 241
Fluctuating Loads and Stresses 242
Fatigue Strength and Fatigue Limit 244
Estimating S-N Curves 246
Stress-Life (S-N) Approach to Fatigue 248
Factors That May Affect S-N Curves 248
Nonzero-Mean Stress 258
Cumulative Damage Concepts and Cycle
Counting 266
Multiaxial Cyclic Stress 272
Fracture Mechanics (F-M) Approach to Fatigue 273
Crack Initiation Phase 273
Crack Propagation and Final Fracture Phases 276
x / Contents
2.15 Reliability: Concepts, Definitions, and
Data 76
System Reliability, Reliability Goals, and
Reliability Allocation 80
Reliability Data 83
2.16 The Dilemma of Reliability Specification
versus Design Safety Factor 84
Chapter 3
Materials Selection 93
3.1 Steps in Materials Selection 93
3.2 Analyzing Requirements of the
Application 93
3.3 Assembling Lists of Responsive
Materials 94
3.4 Matching Responsive Materials to
Application Requirements; Rank Ordered
Data Table Method 105
3.5 Matching Responsive Materials to
Application Requirements; Ashby chart
Method 114
Chapter 4
Response of Machine Elements to Loads
and Environments; Stress, Strain, and
Energy Parameters 123
4.1 Loads and Geometry 123
4.2 Equilibrium Concepts and Free-Body
Diagrams 123
4.3 Force Analysis 124
4.4 Stress Analysis; Common Stress Patterns
for Common Types of Loading 126
Direct Axial Stress 128
Bending; Load, Shear, and Moment
Diagrams 128
Bending; Straight Beam with Pure Moment 133
Bending; Initially Curved Beams 137
Bending; Straight Beam with Transverse
Forces 142
Direct Shear Stress and Transverse Shear
Stress 142
Torsional Shear; Circular Cross Section 150
Torsional Shear; Noncircular Cross Section 152
Torsional Shear; Shear Center in Bending 157
Surface Contact Stress 160
4.5 Deflection Analysis Common Types of
Loading 161
Stored Strain Energy 162
Castigliano’s Theorem 164Design Issues in Fatigue Life Prediction 280
Fatigue Stress Concentration Factors and
Notch Sensitivity Index 280
5.7 Multiaxial States of Cyclic Stress and
Multiaxial Fatigue Failure Theories 283
Chapter 6
Geometry Determination 305
6.1 The Contrast in Objectives Between
Analysis and Design 305
6.2 Basic Principles and Guidelines for
Creating Shape and Size 306
Direct Load Path Guideline 306
Tailored-Shape Guideline 307
Triangle-Tetrahedron Guideline 308
Buckling Avoidance Guideline 309
Hollow Cylinder and I-Beam Guideline 310
Conforming Surface Guideline 310
Lazy-Material Removal Guideline 311
Merging Shape Guideline 313
Strain Matching Guideline 313
Load Spreading Guideline 314
Contents / xi
6.3 Critical Sections and Critical Points 315
6.4 Transforming Combined Stress Failure
Theories into Combined Stress Design
Equations 317
6.5 Simplifying Assumptions: The Need and
the Risk 318
6.6 Iteration Revisited 319
6.7 Fits, Tolerances, and Finishes 323
Chapter 7
Design-Stage Integration of Manufacturing
and Maintenance Requirements 333
7.1 Concurrent Engineering 333
7.2 Design for Function, Performance, and
Reliability 334
7.3 Selection of the Manufacturing Process 334
7.4 Design for Manufacturing (DFM) 337
7.5 Design for Assembly (DFA) 337
7.6 Design for Critical Point Accessibility,
Inspectability, Disassembly, Maintenance,
and Recycling 339
Chapter 8
Power Transmission Shafting; Couplings,
Keys, and Splines 341
8.1 Uses and Characteristics of shafting 341
8.2 Potential Failure Modes 343
8.3 Shaft Materials 344
8.4 Design Equations–Strength Based 345
8.5 Design Equations–Deflection Based 353
8.6 Shaft Vibration and Critical Speed 358
8.7 Summary of Suggested Shaft Design
Procedure; General Guidelines for Shaft
Design 360
8.8 Couplings, Keys, and Splines 361
Rigid Couplings 361
Flexible Coupling 362
Keys, Splines, and Tapered Fits 365
Chapter 9
Pressurized Cylinders; Interference Fits 382
9.1 Uses and Characteristics of Pressurized
Cylinders 382
9.2 Interference Fit Applications 382
9.3 Potential Failure Modes 383
9.4 Materials for Pressure Vessels 383
9.5 Principles from Elasticity Theory 384
9.6 Thin-Walled Cylinders 385
9.7 Thick-Walled Cylinders 386
9.8 Interference Fits: Pressure and Stress 392
9.9 Design for Proper Interference 396
Chapter 10
Plain Bearings and Lubrication 403
10.1 Types of Bearings 403
10.2 Uses and Characteristics of Plain
Bearings 403
10.3 Potential Failure Modes 404
10.4 Plain Bearing Materials 405
10.5 Lubrication Concepts 405
10.6 Boundary-Lubricated Bearing Design 406
10.7 Hydrodynamic Bearing Design 409
Lubricant Properties 410
PART TWO DESIGN APPLICATIONSTightening Torque; Fastener Loosening 507
Multiply Bolted Joints; Symmetric and
Eccentric Loading 509
13.5 Rivets 517
Rivet Materials 517
Critical Points and Stress Analysis 518
13.6 Welds 522
Base Metals, Filler Materials, and Weldability 526
Butt Welds 528
Fillet Welds 529
13.7 Adhesive Bonding 538
Joint Design 538
Structural Adhesive Materials 540
Chapter 14
Springs 546
14.1 Uses and Characteristics of Springs 546
14.2 Types of Springs 546
14.3 Potential Failure Modes 548
14.4 Spring Materials 549
14.5 Axially Loaded Helical-Coil Springs;
Stress, Deflection, and Spring Rate 552
Deflection and Spring Rate 557
Buckling and Surging 559
14.6 Summary of Suggested Helical-Coil
Spring Design Procedure, and General
Guidelines for Spring Design 562
14.7 Beam Springs (Leaf Springs) 568
14.8 Summary of Suggested Leaf Spring
Design Procedure 574
14.9 Torsion Bars and Other Torsion Springs 578
14.10 Belleville (Coned-Disk) Springs 581
14.11 Energy Storage in Springs 582
Chapter 15
Gears and Systems of Gears 594
15.1 Uses and Characteristics of Gears 594
15.2 Types of Gears; Factors in Selection 595
15.3 Gear Trains; Reduction Ratios 600
15.4 Potential failure Modes 605
15.5 Gear Materials 607
15.6 Spur Gears; Tooth Profile and Mesh
Geometry 608
Involute Profiles and Conjugate Action 609
Gearing Nomenclature; Tooth Shape and
Size 610
Gear-Tooth Systems 612
Mesh Interactions 614
xii / Contents
Loading, Friction, and Lubricant Flow
Relationships 410
Thermal Equilibrium and Oil Film Temperature
Rise 416
Design Criteria and Assumptions 419
Suggested Design Procedure 420
10.8 Hydrostatic Bearing Design 425
Chapter 11
Rolling Element Bearings 429
11.1 Uses and Characteristics of Rolling
Element Bearings 429
11.2 Types of Rolling Element Bearings 430
11.3 Potential Failure Modes 433
11.4 Bearing Materials 433
11.5 Bearing Selection 434
Basic Load Ratings 435
Reliability Specifications 435
Suggested Selection Procedure for Steady
Loads 436
Suggested Selection Procedure for Spectrum
Loading 448
Lubrication 451
11.6 Preloading and Bearing Stiffness 453
11.7 Bearing Mounting and Enclosure 457
Chapter 12
Power Screw Assemblies 462
12.1 Uses and Characteristics of Power
Screws 462
12.2 Potential Failure Modes 466
12.3 Materials 466
12.4 Power Screw Torque and Efficiency 467
12.5 Suggested Power Screw Design Procedure 473
12.6 Critical Points and Thread Stresses 474
Chapter 13
Machine Joints and Fastening Methods 485
13.1 Uses and Characteristics of Joints in
Machine Assemblies 485
13.2 Selection of Joint Type and Fastening
Method 485
13.3 Potential Failure Modes 487
13.4 Threaded Fasteners 488
Screw Thread Standards and Terminology 489
Threaded Fastener Materials 492
Critical Points and Thread Stresses 494
Preloading Effects; Joint Stiffness and Gasketed
Joints 49715.7 Gear Manufacturing; Methods, Quality,
and Cost 618
Gear Cutting 618
Gear Finishing 620
Cutter Path Simulation, Mesh Deflection,
and Profile Modification 621
Accuracy Requirements, Measurement Factors,
and Manufacturing Cost Trends 622
15.8 Spur Gears; Force Analysis 624
15.9 Spur Gears; Stress Analysis and Design 626
Tooth Bending: Simplified Approach 626
Tooth Bending: Synopsis of AGMA Refined
Approach 631
Surface Durability: Hertz Contact Stresses and
Surface Fatigue Wear 639
Surface Durability: Synopsis of AGMA Refined
Approach 641
15.10 Lubrication and Heat Dissipation 645
15.11 Spur Gears; Summary of Suggested
Design Procedure 647
15.12 Helical Gears; Nomenclature, Tooth
Geometry, and Mesh Interaction 648
15.13 Helical Gears; Force Analysis 653
15.14 Helical Gears; Stress Analysis and
Design 654
15.15 Helical Gears; Summary of Suggested
Design Procedure 656
15.16 Bevel Gears; Nomenclature, Tooth
Geometry, and Mesh Interaction 662
15.17 Bevel Gears; Force Analysis 665
15.18 Bevel Gears; Stress Analysis and Design 666
15.19 Bevel Gears; Summary of Suggested
Design Procedure 668
15 20 Worm Gears and Worms; Nomenclature,
Tooth Geometry, and Mesh Interaction 675
15.21 Worm Gears and Worms; Force Analysis
and Efficiency 679
15.22 Worm Gears and Worms; Stress Analysis
and Design 682
15.23 Worm Gears and Worms; Suggested
Design Procedure 684
Chapter 16
Brakes and Clutches 701
16.1 Uses and Characteristics of Brakes
and Clutches 701
16.2 Types of Brakes and Clutches 702
16.3 Potential Failure Modes 704
16.4 Brake and Clutch Materials 704
Contents / xiii
16.5 Basic Concepts for Design of Brakes
and Clutches 705
16.6 Rim (Drum) Brakes with Short Shoes 708
16.7 Rim (Drum) Brakes with Long Shoes 719
16.8 Band Brakes 727
16.9 Disk Brakes and Clutches 732
Uniform Wear Assumption 733
Uniform Pressure Assumption 735
16.10 Cone Clutches and Brakes 738
Chapter 17
Belts, Chains, Wire Rope, and Flexible
Shafts 746
17.1 Uses and Characteristics of Flexible
Power Transmission Elements 746
17.2 Belt Drives; Potential Failure Modes 750
17.3 Belts; Materials 752
17.4 Belt Drives; Flat Belts 752
17.5 Belt Drives; V-Belts 757
17.6 Belt Drives; Synchronous Belts 769
17.7 Chain Drives; Potential Failure Modes 769
17.8 Chain Drives; Materials 770
17.9 Chain Drives; Precision Roller Chain 771
17.10 Roller Chain Drives; Suggested Selection
Procedure 774
17.11 Chain Drives; Inverted-Tooth Chain 779
17.12 Wire Rope; Potential Failure Modes 779
17.13 Wire Rope; Materials 782
17.14 Wire Rope; Stresses and Strains 782
17.15 Wire Rope; Suggested Selection
Procedure 786
17.16 Flexible Shafts 791
Chapter 18
Flywheels and High-Speed Rotors 798
18.l Uses and Characteristics of Flywheels 798
18.2 Fluctuating Duty Cycles, Energy
Management, and Flywheel inertia 799
18.3 Types of Flywheels 804
18.4 Potential Failure Modes 805
18.5 Flywheel Materials 805
18.6 Spoke-and-Rim Flywheels 806
Stresses in a Rotating Free Ring 807
Bending Stresses in Flywheel Rim 808
Spoke-Axial Tensile Stresses 809
18.7 Disk Flywheels of Constant Thickness 809
18.8 Disk Flywheels of Uniform Strength 81519.5 Summary of Suggested Crankshaft
Design Procedure 826
Chapter 20
Completing the Machine 843
20.1 Integrating the Components; Bases,
Frames, and Housings 843
20.2 Safety Issues; Guards, Devices, and
Warnings 850
20.3 Design Reviews; Releasing the Final
Design 855
xiv / Contents
18.9 Uniform-Strength Disk Flywheel with
a Rim 816
18.10 Flywheel-to-Shaft Connections 820
Chapter 19
Cranks and Crankshafts 824
19.1 Uses and Characteristics of Crankshafts 824
19.2 Types of Crankshafts 825
19.3 Potential Failure Modes 826
19.4 Crankshaft Materials 826
Table A-4
Section Properties of Selected S
(Standard 1) Shapes 870
Table A-5
Section Properties of Selected C
(Channel) Shapes 871
Table A-6
Section Properties of Selected Equal-Leg
L (Angle) Shapes 872
NSPE Code of Ethics for Engineers 859
Table A-1
Coefficients of Friction 864
Table A-2
Mass Moments of Inertia J and Radii of
Gyration k for Selected Homogeneous Solid
Bodies Rotating About Selected Axes, as
Sketched 867
Table A-3
Section Properties of Selected W
(Wide Flange) Shapes 868
APPENDIX
REFERENCES 873
PHOTO CREDITS 881
INDEX 883
Index
883
Abrasive wear, 23, 25, 59, 62
Acme threads, 463, 464, 470, 471
Adhesive bonding, 538–542
Adhesive wear, 23, 25, 59, 62
American Bearing Manufacturers
Association (ABMA), 430
American Gear Manufacturers Association
(AGMA), 607
Angle shapes (equal leg), section
properties, 872
Angular velocity ratio, 595, 600–605
Anthropometrics, 5
Archard adhesive wear constant, 60
Area moment of inertia (table), 135
Ashby charts, 105–111, 114–120
ASME Boiler and Pressure Vessel Code, 382
Asperities, surface, 59, 409
Assembly, design for, 337, 338
Assembly process, selection, 337, 338
Backlash (gears), 618
Ball screws (see power screws)
Baseplates, 843, 844
Bases, 843
Beam springs, 568–578 (also see springs)
Bearings:
antifrictional (see rolling element bearings)
basic load rating, 62
journal (see plain bearings)
plain (see plain bearings)
rolling element (see rolling element
bearing)
sleeve (see plain bearings)
sliding (see plain bearings)
Belleville springs (coned disk), 581, 582
Belts:
failure modes, 750, 751
flat, 752–756
flat belt selection. 754–756
materials, 752
synchronous, 769
timing, 769
uses, 746
V-belts, 756–768
V-belt datum system, 759
V-belt pitch system, 759
V-belt selection, 763–768
Bending:
curved beams, 137–142
gear teeth (see gears)
load, shear, and moment diagrams (table),
128–133
neutral axis, 134, 138, 144
pure bending, 134
spring rate, 180, 181
straight beams, 128–137
transverse loads, 142–150
transverse shear, 142–150
Bevel gears, 662–675 (also see gears)
Biaxial brittle fracture strength data, 226
Biaxial state of stress, 127, 205–213
Biaxial yield strength data, 227
Body force, 123
Boundary conditions, 385, 387, 388
Bolts, (see fasteners)
Brakes:
band, 727–732
caliper, 735, 736
cone, 738, 739
design procedure, 705–707
disk, 732–738
external shoe, 703, 708, 724
failure mode, 704
friction coefficient (table), 706
friction lining material, 706
internal shoe, 703, 708, 724
long-shoe drum type, 719–727
multiple disk, 732–738
materials, 704–706
self-energizing, 708
self-locking, 708
short-shoe drum type, 708–719
temperature rise, 711, 712
types, 702–704
uniform pressure assumption (disk), 735
uniform wear assumption (disk), 733, 734
uses, 701, 702
Brinnelling, 23, 24
Brittle fracture, 23, 24, 225, 233–241
Buckling, 23, 27, 34–45
Buckling:
column, 35, 36
critical buckling load, 35–44
critical unit load, 40
effective column length, 38
effective slenderness ratio, 39
end support influence, 36, 38
Euler’s critical load, 38
Euler-Engesser equation, 39
externally pressurized thin-walled
tubes, 44
helical coil springs, 559–561
initially crooked columns, 39, 40
local buckling, 41
long columns, 41
long thin rod, 43, 44
onset of, 35
pin-jointed mechanisms, 35, 36
primary buckling, 41
secant formula, 39, 40
short columns, 40, 41
thin deep beams, 44
Buckling avoidance guideline, 309, 310
Butt welds, 528
Buttress thread, 463, 464
Castigliano’s theorem, 164–171
Cathodic protection, 66
Chains:
chordial action, 773, 774
failure modes, 769, 770
inverted tooth, 779
materials, 770, 771
multiple strand factor (table), 773
precision roller chain, 771–779
precision roller chain, selection, 774–779
polygonal action, 773, 774
silent, 779
uses, 746
Channel shape, section properties, 871
Clutches:
band, 727–732
cone, 738, 739
design procedure, 705–707
disk, 732–738Clutches (Continued)
failure modes, 704
friction coefficients (table), 706
friction lining material, 706
materials, 704–706
multiple disk, 732–738
temperature rise, 711, 712
types, 702–704
uniform pressure assumption (disk), 735
uniform wear assumption (disk), 733,
734
uses, 701, 702
Code of ethics (NSPE), 14, 15, 859–863
Codes, 13
Codes and standards, 13
Coefficient of speed fluctuations
(flywheels), 800, 801
Cold-rolling, 189
Columns (see buckling)
Combined creep and fatigue, 23–28
Combined stress design equations, 317, 318
Combines stress theory of failure, 33,
224–233, 317, 318
Conceptual design, 8
Concurrent design, 333, 336
Concurrent engineering, 333, 336
Conforming surface guideline, 310, 311
Configurational guidelines, 306–315
Configurational guidelines:
buckling avoidance, 309, 310
conforming surfaces, 310, 311
direct load path, 306, 307
hollow cylinder and I-beam, 310
lazy material removal, 311, 312
load spreading, 314
merging shape, 313
strain matching, 313, 314
triangle-tetrahedron, 308, 309
tailored shape, 307, 308
Constant thickness disk flywheel, 809–815
(also see flywheels)
Contact stress (Hertz), cylinders, 176–179
Contact stress (Hertz), spheres, 174–175
Corrosion:
biological corrosion, 23, 25, 64
cathodic protection, 66
cavitation corrosion, 23, 25, 64, 65
direct chemical attack, 23, 25, 64
erosion corrosion, 23, 25, 64
galvanic corrosion, 23, 25, 64, 65
hydrogen damage, 23, 25, 64
intergranular corrosion, 23, 25, 65
pitting corrosion, 23, 25, 65
protection, 65
sacrificial anode, 65
selective leaching, 23, 25, 64
stress corrosion, 23, 25, 64–66
Corrosion fatigue, 23, 28, 64
Corrosion fatigue strength properties
(table), 102
Corrosion wear, 23, 28
Couplings:
bellows, 363, 364
elastomeric disk, 363, 364
failure modes, 363–365
flexible, 361, 363–365
flexible disk, 362, 363
gear, 363, 364
rigid, 361, 362, 369–372
roller chain, 363, 364
rubber cap, 364
sliding disk, 363, 364
spring, 363, 364
universal joint (U-joint), 365
Crack:
initiation, 241, 242, 273–279
length, 233
opening mode (Mode I), 233
propagation, 233, 241, 276–279
size, unstable (critical), 241, 276–279
surface, 233
surface flaw shape parameter, 233, 236
through-the-thickness, 234–237
Crankshaft:
center cranks, 825
design procedure, 826–841
disk cranks, 825
failure modes, 826
materials, 826
side cranks, 825
types, 825
uses, 824, 825
Creep, 23, 26, 52–58
Creep:
constant creep rate, 56
cumulative creep, 57, 58
Larson-Miller theory, 54
logarithmic creep, 56
log-log stress-time creep, 65
long-term creep, 53–58
parabolic creep, 56
Robinson hypothesis, 57, 58
Stage I transient creep, 56
Stage II steady-state creep, 56
true creep strain, 56
under axial stress, 55–58
Creep buckling, 23, 28
Creep deformation, 53
Creep-limited maximum stress (table), 98
Creep strain, 52
Creep rupture, 52, 53
Creep testing:
abridged method, 53
mechanical acceleration method, 53
thermal acceleration method, 53
Critical points, 315–317, 474–481,
494–497, 582, 583
Critical point accessibility, design for, 339,
340
Critical sections, 315–317
Critical speed, rotating shafts, 358–360
Critical stress intensity factor, 234, 237, 238
Cumulative creep prediction, 57, 58
Cumulative damage, 241, 242, 266–272
Cumulative distribution function, 253
Curved beams, 137–142
Curved surfaces in contact, 174–179
Customer attributes, 3, 4
Customer perceptions, 5
CV joints, 365
Cycle counting, rain flow method, 266–272
Cyclic equivalent stress, 283–291
Cyclic multiaxial state of stress, 283–291
Cyclic stresses, 242–291
Deflection:
axial loading, 161
bending, 129–133, 162, 164
Castigliano’s theorem, 164–171
cylinders in contact, 176
shafts, 353–358
spheres in contact, 174
Hertz contact, 161, 174, 176
torsional loading, 161
Deflection analysis, 126
Design:
concurrent, 333, 336
detail design, 8
embodiment design, 8
fail safe design, 9
intermediate design, 8
mechanical design, 1
preliminary design, 7, 8
safe life design, 9
Design equations, combined stress, 317, 318
Design for assembly (DFA), 337, 338
Design for manufacturing (DFM), 337
Design for “X” (DFX), 333, 334
Design reviews, 10, 855
Design safety factors, 7, 33, 71–74, 84
Design steps, 9–11
Detail design, 8
Development and field service, 9
Dilatation energy per unit volume, 227, 228
Direct load path guideline, 306, 307
Direct shear, spring rate, 181
Disassembly, design for, 339, 340
Distortion energy design equation, 228
Distortion energy failure theory, 33, 224,
225, 227–232
Distortion energy per unit volume, 228
Distribution function (see probability
density function)
Ductile rupture, 23, 24, 33, 34
Ductility properties (table), 99, 100
Durability of gear teeth (see gears)
Effective stress, 228
Efficiency:
power screws, 467–473
worm gears, 679–682
Elastic instability (see buckling)
Elastic strain, 31, 32
884 IndexElastic stress-strain relationships, 214, 215
Elasticity theory (see theory of elasticity)
Elevated temperature strength (table), 96, 97
Embodiment design, 8
Energy methods:
Castigliano’s theorem, 164–171
Impact, 47–52
Engineering strain, 29, 30
Engineering stress-strain diagram, 30
Environmental effects, 194, 195
Epicylic gears, 600–605
Equilibrium, 123, 124, 385, 393, 412
Equivalent alternating stress amplitude,
283–291
Equivalent cyclic stress, 283–291
Equivalent mean stress, 283–291
Equivalent stress, 228, 272, 283–291
Ergonomics, 5
Ethics, 13, 14
Ethics, code of, 14, 15, 859–863
Ethical dilemma, 14
Euler’s critical load, 38
External energy, 47
Fail safe design, 9, 82
Failure analysis, 70, 71
Failure criteria, 22
Failure modes, 23–28 (also see mechanical
failure)
Failure prevention perspective, 22–70,
233–280
Failure theories:
distortional energy theory (also known as
octahedral shear stress theory,
Huber-von-Mises- Henky theory, or
von-Mises theory), 33, 225
fatigue, 224–232, 241–291
maximum normal stress theory (also
known as Rankine theory), 225
maximum shearing stress theory (also
known as Tresca Guest theory), 226,
227
selection of, 229
Fasteners:
bolts, 487, 496, 497
critical points, 494–497, 518–522
failure modes, 495–497
head styles, 488
lead (thread), 489
materials, 492–494
metric threads, 491
multiple threads, 489
reduced-body bolts, 487
rivets, 517–522
screw thread standards, 488, 489
thread angle, 489
thread series, 492
thread major diameter, 489
thread minor diameter, 489
thread specifications, 492
thread stresses, 494–497
tightening, 507, 508
torque coefficient, 508
unified inch, threads, 490, 491
Fastener loosening, 507–508
Fatigue:
completely reversed stress, 242, 258
corrosion fatigue, 28
crack growth rate, 276
crack initiation, 241, 242, 273–279
crack propagation, 233, 241, 276–279
critical (unstable) crack size, 241, 276–279
cumulative damage, 241, 242, 266–272
cycle ratio, 266–269
cyclic strain-hardening exponent, 274,
275
cyclic strength coefficients, 274, 275
damage fraction, 266–269
definitions for constant-amplitude stress
time pattern, 242, 243
estimating properties of a part, 257
elastic strain amplitude, 274, 275
estimating S-N curves, 246–248
factors that may affect S-N curves,
248–258
failure theories, 283–291
fatigue life, 241
fatigue limit, 244, 245
fatigue strength, 244, 245
final fracture, 276–278
fluctuating loads, 241
fracture mechanics approach
(F-M approach), 242
fretting fatigue, 23, 26, 66, 67, 69
high-cycle fatigue, 23, 24, 241–280
histogram, 245
impact fatigue, 23
infinite life diagram, 256
life improvement from residual stress,
288–291
life improvement form shot-peening,
288–291
linear damage rule, 266–269
loading spectra, 242
local stress-strain approach to crack
initiation, 273–279
low-cycle fatigue, 23, 24, 242
master diagram, 258, 259
modified Goodman relationships, 260,
261–266
multiaxial cyclic stress, 272
Neuber rule, 274
nonzero mean stress, 243, 258–266
Palmgren-Miner hypothesis, 266–269
Paris law, 277
plastic strain amplitude, 274, 275
probability of failure, 245
rain flow cycle counting, 254, 266–272
range of stress, 243, 276
released tension, 243
reliability, 245
reversals to failure, 274, 275
sample standard deviation, 245
sample mean, 245
scatter of life diagram, 244, 245
S-N curves, 244
SNP curves, 244, 245
standard deviation of fatigue strength, 253
strain-controlled fatigue (see low-cycle
fatigue)
stress life approach (S-N approach), 242,
243, 248
strength-influencing factors for S-N
curves, 247–258
strength reliability factors, 247
stress intensity factor range, 276, 277
stress spectra, 242, 266
surface fatigue, 23, 24
test method influence on S-N data, 248
thermal fatigue, 23, 24
total strain amplitude, 274, 275
zero-mean stress, 243, 258
Fatigue limit, 244, 246
Fatigue strength, 244, 246
Fatigue strength reduction factor, 281–283
Fatigue stress concentration factor, 280–283
Fillet welds, 529–537
Finishes, 328, 330
Fits, 323–329
Flexible shafts:
maximum operating torque (tables), 792,
793
selection procedure, 793–795
uses, 748–750
Fluctuating loads, 242
Flywheels:
bending in flywheel rims, 808, 809
coefficient of speed fluctuation, 800, 801
connection to shaft, 820, 821
constant thickness disk, 809–815
design for speed control, 799–804
energy management, 799–804
failure modes, 805
fluctuating duty cycle, 799–804
materials, 805, 806
rotating free ring, 807, 808
spoke-and-rim, 806–809
tension in flywheel spokes, 808, 809
types, 804, 805
uniform strength disk, 815, 816
uniform strength disk with rim, 816, 817
uses, 798
Force analysis, 124–126
Force flow lines, 124,125, 215
Force-induced elastic deformation, 23, 24,
28–31
Fracture mechanics, 233–241
Fracture mechanics approach to fatigue,
273–279
Fracture toughness, plane strain, 237
Frames:
C-frame, 844
design procedure, 845–850
Index 885Frames (Continued)
failure modes, 844
materials, 844
O-frame, 844
open truss, 843, 844
stressed-skin structure, 843, 844
thin-walled shell, 843, 844
Free body diagram, 123–126, 191, 386, 467
Fretting, 23, 26, 66–70
Fretting:
fretting action, 26, 66
fretting corrosion, 23, 26, 66
fretting fatigue, 23, 26, 66–68
fretting wear, 23, 26, 66, 68, 69
maps, 69
minimizing or preventing fretting
damage, 69, 70
Friction coefficients (table), 864–866
Friction wheel drives, 594, 595
Galling, 23, 27, 61
Gasketed joint, 497–507
Gasket materials, (table), 503
Gears:
angular velocity ratio, 595, 600–605, 609
backlash, 618
bevel:
applications, 597, 598
bending (tooth) – AGMA refined
approach, 667, 668
design procedure, 668–675
force analysis, 665, 666
nomenclature, 662–665
standard AGMA tooth proportions,
(table), 665
stress analysis, 666–668
surface durability using AGMA refined
approach, 667, 668
compound, 600–605
epicyclic, 600–605
external, 594, 595
face gear, 598
failure modes, 605–607
fundamental law, 595
helical:
applications, 597
bending (tooth) – AGMA refined
approach, 654, 655
contact-pattern, 649
design procedure, 656–662
force analysis, 653, 654
nomenclature, 648, 650
standard AGMA tooth proportions,
(table), 651
stress analysis, 654, 655
surface durability using AGMA refined
approach, 654, 655
herringbone, 597
hypoid, 598
internal, 594, 595
involute, 608–618
Lewis equation (bending), 626–629
Lewis form factor, 628
line of action (pressure line), 609
manufacturing cost trends, 624
manufacturing methods:
accuracy requirements (table), 623,
624
gear cutting, 618–620
gear finishing, 620
profile modification, 621, 622
materials, 607, 608
rack and pinion, 597
reduction ratios, 600–605
selection of type, 595–600
simple, 600–605
spiroid, 598
straight tooth spur:
angular velocity ratio, 595, 600–605,
609
applications, 595, 597
approximate actual size, 614
bending (tooth) – AGMA refined
approach, 631–638
bending (tooth) – simplified approach,
626–631
conjugate action, 609
design procedure, 647, 648
force analysis, 624–626
involute profile, 608–618
lubrication, 645–647
nomenclature, 594, 610
standard AGMA tooth proportions,
(table), 613
stress analysis, 631–645
surface durability using AGMA refined
approach, 641–645
surface durability using Hertz contact
stresses, 639–641
tooth profile, 608–618
surface durability, 62, 639–645, 655, 667,
668
tooth bending, 626–638, 654, 655, 667,
668
tooth durability, 632–645, 655, 667, 668
trains, 600–605
types, 595–600
uses, 594, 595
worm:
allowable tangential gear force, 682,
683
applications, 599
bending (tooth), 682
common thread profiles, 676
design procedure, 684–691
efficiency, 679–682
force analysis, 679–682
nomenclature, 675
stress analysis, 682, 683
surface durability, 682
typical tooth profiles, (table), 677
Zerol, 597, 598
Geometric compatibility, 385, 387, 392
Geometry determination, 305–330
Hardness properties, (table), 101
Heat affected zone (HAZ), 528
Helical coil springs, 546, 552–568
(also see springs)
Helical gears, 648–662 (also see gears)
Hertz contact deflection, 177, 453–457
Hertz contact spring rate, 181–182, 453
Hertz contact stress, 24, 62, 160, 161,
174–179
High-speed-rotors (see flywheels)
Hollow cylinder guidelines, 310
Hooke’s Law, 32, 47, 162, 214, 215, 228,
385, 387, 393
Horsepower relationship, 152
Housing, 844
Huber-von-Mises-Hencky Theory
(see distortional energy theory)
Human factors engineering, 5
House of quality, 3
I-beam guidelines, 308
I-beams, section properties, 870
Impact, 23, 26
Impact:
deflection, 47–52
deformation, 23, 26
energy method, 47–52
fatigue, 23
fracture, 23, 26
fretting, 23
stress, 47–52
stress wave propagation, 46
suddenly applied load, 46, 48
wear, 23, 26
Industrial designers, 2
Inspectability, 9
Inspectability, design for 339, 340
Interference fits:
design procedures, 396–400
failure modes, 386
uses, 382, 386
Intermediate design, 8
Involute gear teeth, 609–618
Involute splines, 373, 374
Iteration, 7, 319
Jack screws (see power screws)
Joints:
adhesively bonded, 538–542
advantages of adhesive bonding, 838
bolted, 486, 487–516
butt weld, 528
centroid of bolt pattern, 510, 511
centroid of weld pattern, 530
eccentric loading, 509–516, 529–537
failure modes, 487, 488
fillet welds, 529–537
gasketed, 497–507
886 IndexJoints (Continued)
moment of inertia, 510, 512
multiply bolted, 509
multiply riveted, 519
multiply welded, 529–537
preload, 495–507
rivet material, 517
riveted, 517–522
stiffness, 497–507
torsion-like shear, 509–516
types, 485, 486
weld edge preparation, 525, 526
weld electrode specifications, 527
weld types, 525, 526
weldability, 527
welded, 522–537
weld heat affected zone (HAZ), 528
weld stress concentration factors, 525
weld symbol, 524
Keys, 361–372
Keys:
failure modes, 366
square, 365–372
stress concentration factors (keyway),
220, 367, 369
Woodruff, 365, 367
Kinematic viscosity, 410, 411, 414
Larson-Miller parameter, 54
Lazy-material removal guideline, 611, 612
Lead screw (see power screws)
Leaf springs, 568–578 (also see springs)
Lessons learned strategy, 12
Lewis equation (see gears), 626–629
Line of action (see gears), 609
Linear actuators (see power screws)
Linear elastic fracture mechanics (LEFM),
233–241
Load sharing, 179–186
Load spreading guideline, 314
Loading severity parameter, 225
Lubrication:
boundary, 406–409
elastohydrodynamic (squeeze film), 406,
452, 645–647
hydrodynamic, 406, 409–425
hydrostatic, 409
Petroff’s equation, 411
pV product, 406–409
Raimondi and Boyd data, 413–417
Reynolds equation, 412, 413
plain bearings, 403, 405–425
rolling element bearings, 452
solid film, 406
Sommerfield data, 413–417
thick film (full film), 405, 409–425
thin film (partial film), 405–409
Tower experiments, 412
viscosity, 410, 411, 414
zero film, 405
Machinability index (table), 104
Maintenance, design for, 333, 339, 340
Manufacturing, 333–340
Manufacturing, design for, 337
Manufacturing process, selection, 334–337
Manufacturing process suitability (table), 103
Marketing specialists, 1, 2
Mass moments of inertia (table), 867
Materials:
application requirements, 94
Ashby charts, 105–111, 114–120
mechanical properties (tables), 95–105,
106–109, 238
performance evaluation indices, 94
selection by Ashby method, 105–111,
114–120
selection by rank-ordered data (table),
105–114
selection steps, 93
Materials cost index, 104
Maximum shearing stress design
equation, 318
Maximum shearing stress failure
theory, 225–227
Maximum normal stress design equation, 318
Maximum normal stress failure theory, 225,
226
Mean, 77
Mechanical design:
concepts, 6
definition, 6
failure prevention perspective, 22–75
Mechanical failure:
brinnelling, 23, 24
brittle fracture, 23, 24, 233–241
buckling, 23, 27, 34–45
combined creep and fatigue, 23, 28
corrosion, 23, 24, 64–66
corrosion fatigue, 23, 28, 64
corrosion wear, 23, 28, 64
creep, 23, 26, 27, 52–58
creep buckling, 23, 28
ductile rupture, 23, 24, 33, 34
fatigue, 23, 24, 241–291
force-induced elastic deformation, 23,
24, 30
fretting, 23, 26, 66–70
galling, 23, 27, 61
impact, 23, 26, 46–52
modes of, 23–28
radiation damage, 23, 27, 102, 103
seizure, 23, 27, 61
spalling, 23, 27
stress corrosion, 23, 28, 65, 66
stress rupture, 23, 27, 52–58
temperature-induced elastic deformation,
23, 24, 31, 32
thermal relaxation, 23, 27
thermal shock, 23, 27
wear, 23, 25, 59–63
yielding, 23, 24, 32, 33
Membrane analogy, 153–155
Merging shape guidelines, 313
Mode I crack displacement, 233
Mode II crack displacement, 233
Mode III crack displacement, 233
Modified square thread, 463, 464
Mohr’s circle (strain), 213, 214
Mohr’s circle (stress), 210, 211
Moment diagrams, bending (table),
129–133
Moment of inertia, area (table), 135
Moment of inertia, mass (table), 867
Multiaxial cyclic stress, 283–291
Multiaxial fatigue failure theories, 283–291
Multiaxial state of stress, 127, 205–215
Multiple threads, 464, 465
National Society of Professional Engineers
(NSPE), Code of Ethics, 14, 15,
859–863
Neuber rule, 274
Newtonian fluid, 410
Newton’s law of cooling:
bearings, 418
brakes, 712
gears, 646
Nondestructive evaluation (NDE), 339
Normal (Gaussian) distribution, 76–80
Normal stress, 126, 127
Notch sensitivity, 280–283
Octahedral shear stress theory of failure (see
distortion energy failure theory)
Paris law (fatigue), 277
Petroff’s equation, 411
Pins, 376, 377
Plain bearings:
advantages, 403, 404
design criteria, 419, 420
design procedure, 420–425
eccentricity ratio, 413, 421
failure modes, 404
lubrication, 403, 405–425
materials, 405
oil film temperature rise, 416, 418
recommended clearances (table), 420, 421
uses, 403, 404
Plane cross section properties (table), 135
Plane strain:
critical stress intensity factor, 237
definition, 237
minimum thickness for, 237
Plain strain fracture toughness, 237, 276
Plane stress, critical stress intensity factor,
237
Planetary gears, 600–605
Plastic strain, 32
Policy of least commitment, 3
Power, as related to torque and speed, 151,
152
Index 887Power screws:
Acme threads, 463, 464, 470, 471
back driving, 467
ball screw, 465
buttress thread, 463, 464
design procedures, 473, 474
efficiency, 467–473
failure modes, 466
helix angle, 464
lead (thread), 464
lead angle, 464, 469
materials, 466
modified square thread, 463, 464
multiple threads, 464, 465
overhauling, 469
pitch, 464
self-locking, 469
square thread, 463, 464
thread angle, 463
threads, 463–470
torque, 467–473
uses, 462
Preliminary design, 7, 8
Preloading, 186–189, 453–457
Presetting, 189
Pressure vessels:
ASME Boiler and Pressure Vessel Code,
382
failure modes, 383
longitudinal stress, 386
materials, 383, 384
tangential (hoop) stress, 385
thick wall, 382, 386–392
thin wall, 382, 385, 386
uses, 382
Prestressing, 190–192
Principal normal stress, 205–213
Principal planes, 205–213
Principal stresses, 205–213, 389
Principal shearing stress, 205–213
Projected area, 386
Probability density function, 76–79
Probability of failure, 76–79, 245
Probabilistic design, 76
Product design team, 1, 2, 3
Product marketing concept, 3
Radiation damage, 23, 27, 102, 103
Radiation exposure influence on properties
(table), 102, 103
Rain flow cycle counting (fatigue), 254,
266–272
Rankine’s theory (see maximum normal
stress theory)
Recycling, design for, 339, 340
Redundant assemblies, 179–186
Redundant supports, 166–169, 179–186
Redundancy, component level, 82, 83
Redundancy, sub-assembly level, 82, 83
Reliability, 76–84, 245
Reliability:
allocation, 80
block diagrams, 81
definition, 76
equal apportionment, 83
functional block diagrams, 81–83
goals, 80, 81
log-normal distribution, 76
normal cumulative distribution, 77–79
normal distribution, 77–80
parallel components, 82, 83
population mean, 77
population standard deviation, 77
population variance, 77
redundancy at component level, 82, 83
redundancy at subsystem level, 82, 83
series components, 82
Six Sigma, 81
standard normal variable (table), 78
system, 80–83
specification, 84
Weibull distribution, 76
Residual stresses, 189–194, 525
Residual stresses:
cold-rolling, 190
estimating, 190–194
fatigue life improvement, 288–291
presetting, 189
prestressing, 190–192
shot-peening, 190, 526
weldments, 525, 526
Resilience properties (table), 100
Resonance, 344, 359
Retrospective design, 70, 71
Reynolds equation, 412
Rivets (see fasteners)
Rolling element bearings:
ball, 430, 431
basic dynamic load rating, 435
basic static load rating, 435
enclosure, 457, 458
failure modes, 433
force-deflection curves, 453–457
lubrication, 451, 452
materials, 433, 434
mounting practices, 457, 458
preloading, 453, 457
reliability, 435, 436
roller, 430, 432
selection for spectrum loading, 434,
448–451
selection for steady loads, 434, 436–448
stiffness, 453–457
types, 430–432
uses, 429
Rotors, high-speed (see flywheels)
Rotating free ring, 407, 408
Safe life design, 9
Safety factor:
design, 7, 33, 72–74, 84
existing, 75
rating factors, 73
rating numbers, 72, 73, 84
Safety issues:
devices, 850, 852–854
guards, 850, 851
hazards, 850
risk, 850
Sample mean, 245
Sample standard deviation, 245
Screw threads:
Acme, 463, 464, 470, 471
buttress, 463, 464
failure modes, 466
helix angle, 464
lead, 464
lead angle, 464, 469
modified square, 463, 464
multiple threads, 464, 465
pitch, 464
square, 563, 464, 468
thread angle, 463
Screws, power (see power screws)
Seizure, 23, 27, 61
Setscrews, 365, 275, 376
Setscrews:
holding power, 376
types of points, 375
Shaft deflection, 353–358
Shaft strength, 345–353
Shafts:
connection to flywheels, 820, 821
critical speed, 358–360
design equations, deflection based,
353–358
design equations, strength based,
345–353
design layout, 343
design procedure, 360, 361
failure modes, 343, 344
flexible (see flexible shafts)
materials, 344, 345
standard for design of, 345
uses, 341–343
vibration, 358–360
Shear center, 158–160
Shearing stress, 126, 127, 142–148
Shock (see impact)
Shot-peening, 190
Shot-peening, fatigue life improvement,
288–291
Simplifying assumptions, 318
Six Sigma, 81
Slider-crank mechanism, 824
Solid bodies, properties of (table), 867
Spalling, 23, 27
Specification, reliability, 84
Specifications, engineering, 2, 8, 11, 93
Specifications, thread, 492
S-N curves, estimating, 246–248
S-N curves, strength-influencing factors,
247–258
888 IndexSplines, 361, 373, 374
Splines:
failure mode, 373
fits, 373
involute, 374
straight, 373, 374
stress concentration factors, 374
Spoke-and-rim flywheel, 806–809
(also see flywheel)
Spring index, 554
Springs:
Belleville (coned disk), 581, 582
buckling of helical coil, 559, 560
curvature factor in helical coil, 554
end loop stress concentration, 555, 556
energy storage, 582–586
fatigue shearing strength (table), 563
helical coil, 546, 552–568, 579
helical coil design procedure, 562–568
helical coil nomenclature, 552
helical coil spring index, 554
helical coil spring rate, 558
leaf springs, 568–578
leaf spring design procedure, 574–578
leaf spring spring-rate, 572
linear, 181
machine elements as, 180–186
nonlinear softening, 181
nonlinear stiffening (hardening), 181
parallel, 176–186
series, 179–186
shackles, 572–573
spiral torsion, 579, 580
surging of helical coil, 561
torsion bar, 578–581
torsion in helical coil, 553
torsion springs, 578–581
torsion tubes, 578
torsional shear yield strength (table), 560
transverse shear in helical coil, 553
Wahl factor, 554, 555
Spring rate (spring constant), 29, 179–186,
557, 558
Spring rate:
axial, 30, 181
bending, 181
direct shear, 181
helical coil, 557–559
Hertz contact, 181
leaf spring, 572
linearized, 181, 453
torsional, 181
Spur gears, 608–618 (also see gears)
Square thread, 463, 464, 469
Stages of design, 7–9
Standard deviation, 77
Standard normal variable, 253, (table), 78
Standards, 13
State of stress:
biaxial, 127, 205–213, 386
multiaxial, 127, 205–213, 225
multiaxial cyclic, 272, 283–291
triaxial, 127, 205
uniaxial, 127, 225
Stiffness, joint, 497–507
Stiffness properties of materials (table),
99
Straight toothy spur gears, 608–648
(also see gears)
Strain amplitude, elastic, 274, 275
Strain amplitude, plastic, 274, 275
Strain amplitude, total, 274, 275
Strain cubic equation, 213
Strain energy, 47, 126, 162–173, 227
Strain energy per unit volume, 227
Strain gage, 214
Strain-matching guideline, 313
Strain rosette, 241
Strength at elevated temperature (table),
96, 97
Strength properties (table), 95, 96
Strength reduction factor, 281
Strength/weight ratio (table), 96
Stress (see “stress patterns” and “state of
stress”)
Stress, equivalent, 272
Stress concentration, 215–224
Stress concentration:
actual local stress, 216
highly local, 216–224
multiple notches, 217, 223
nominal stress, 216
notch root, 216
notch sensitivity index, 280–283
strength reduction factor, 281
widely distributed, 138, 139, 216
Stress concentration factors:
crankshaft fillet, 222
curved beams, 138, 139
cyclic multiaxial states of stress, 281,
282
end-of hub pressed on shaft, 223
fatigue, 216, 217
fatigue of brittle materials, 282
fatigue of ductile materials, 282
flat bar with shoulder fillet, 221
gear tooth fillet, 222
helical coil spring in torsion, 580
intermediate and low-cycle range,
282
keyways (profiled, slender runner), 367,
369
keyways (Woodruff), 367
screw threads, 217
shaft diametral hole, 220
shaft fillet, 218
shaft groove, 219
shaft keyway, 220, 366–369
shaft splines, 220, 374
theoretical elasticity, 216
torsion of helical coil spring, 580
weldment, 525
Stress corrosion, 23, 28, 64
Stress cubic equation, 206–209
Stress intensity:
critical, 234
stress intensity factor, 233
Stress intensity factor, 233–237
Stress patterns:
bending, 128–137
direct stress, 128
surface contact stress, 128, 160
torsional shear, 128, 150–160
transverse shear, 128, 142–150
Stress relaxation, 27
Stress rupture, 23, 27, 52–58
Stress rupture strength (table), 97
Stress wave propagation, 46
Structural adhesives (table), 541
Structural shapes, section properties,
867–872
Suddenly applied load, 48
Superposition, principal of, 32
Surface contact stress, 160
Surface forces, 123
Surging, helical coil springs, 561
System reliability, 80–83
Tailored-shape guidelines, 307, 308
Tapered fits, 274, 375
Temperature-induced elastic deformation,
23, 24, 31, 32
Theoretical stress concentration factor, 216
Theories of failure:
distortional energy theory, 225, 227,
228
maximum shearing stress theory,
225–227
maximum normal stress theory, 225,
226
selection of, 229
Theory of elastic principles, 384–386
Thermal conductivity (table), 104, 105
Thermal expansion coefficients (table), 98
Thermal shock, 23, 27
Thermal relaxation, 23, 27
Thermal stress (temperature induces stress),
32
Threads:
fasteners, 488–497
power screws, 463–470
Tolerances, 323–329
Tooth bending, 631–639, 654, 655, 667, 668
(also see gears)
Topological interference, 824
Torsion:
circular cross section, 150–156
deflection, 161
noncircular cross section, 152–155
shear center in bending, 157–160
spring rate, 181
Torsion bar springs, 578–581 (also see
springs)
Index 889Total strain energy per unit volume, 227
Toughness properties (tables), 100, 238
Transverse shear, 142–147
Tresca-Guest theory (see maximum
shearing stress theory)
Triangle-tetrahedron guideline, 308, 309
Uniaxial state of stress, 127, 225, 233
Unit inertia (table), 532, 533
Units, 14–20
Units:
absolute system, 15, 16
base units, 15
conversion table, 17
derived units, 15
foot-pound-second system (fps), 14
gravitational system, 15
inch-pound-second system (ips), 14
International system (SI), 14
standard prefixes, 17
Universal joint, 365
Variance, 77
Virtues of simplicity, 10
Viscosity, 410, 411, 414
von Mises stress, 228
von Mises theory (see distortional
energy theory)
Whal factor, 554, 555
Wear, 23, 25, 59–63
Wear:
abrasive wear, 23, 25, 59, 61, 62
abrasive wear constant, 62
adhesive wear, 23, 25, 59, 61, 62
Archard adhesive wear constant, 60
corrosion wear, 23, 25, 59
deformation wear, 23, 26, 59
fretting wear, 23, 26, 66, 68
impact wear, 23, 26
mean normal contact pressure, 60, 61
principle of conversion, 61
principle of diversion, 61
principle of protective layers, 61
surface fatigue wear, 23, 25, 59, 62
three-body wear, 61
two-body wear, 61
Weibull distribution, 76
Weldability, 526
Welded joints (see joints, welded)
Weld symbol, 524–526
Wide flange beam, section properties, 868,
869
Wire rope:
failure modes, 779–781
fatigue data, 785
materials, 782
selection procedure, 786–791
stresses, 782, 784–791
uses, 748, 749
Worm gears, 675–691 (also see gears)
Yielding, 23, 24, 32, 33
Yield strength (table), 95
كلمة سر فك الضغط : books-world.net
The Unzip Password : books-world.net
تحميل
يجب عليك التسجيل في الموقع لكي تتمكن من التحميل
تسجيل | تسجيل الدخول