Mechanical Behavior of Materials

For upper-level undergraduate engineering courses in Mechanical Behavior of Materials.   Mechanical Behavior of Materials, 4/eintroduces the spectrum of mechanical behavior of materials, emphasizing practical engineering methods for testing structural materials to obtain their properties, and predicting their strength and life when used for machines, vehicles, and structures. With its logical treatment and ready-to-use format, it is ideal for practicing engineers and upper-level undergraduates who have completed elementary mechanics of materials courses.

Norman E. Dowling earned his B.S. in civil engineering (structures) from Clemson University in Clemson, S.C., and his M.S. and Ph.D. in theoretical and applied mechanics from the University of Illinois in Urbana.

 

An ASTM International member since 1972, Dowling serves on a number of E08 subcommittees and has recently been member-at-large of the E08 Executive Subcommittee. Professionally he has worked in the areas of fatigue, fracture, and deformation of engineering materials and components. Specific topics of interest include life prediction for irregular loading histories, plasticity effects on notches and in crack growth, and standard test methods for low cycle fatigue and for fatigue crack growth. He has also consulted on applications to engineering design, troubleshooting, and failure analysis.

 

In addition to ASTM International, Dowling is a member of the Fatigue Design and Evaluation Committee of the Society of Automotive Engineers, ASM International, and Sigma Xi.

1 Introduction 1

1.1 Introduction 1

1.2 Types of Material Failure 2

1.3 Design and Materials Selection 10

1.4 Technological Challenge 16

1.5 Economic Importance of Fracture 18

1.6 Summary 19

References 20

Problems and Questions 20

 

2 Structure and Deformation in Materials 22

2.1 Introduction 22

2.2 Bonding in Solids 24

2.3 Structure in Crystalline Materials 28

2.4 Elastic Deformation and Theoretical Strength 32

2.5 Inelastic Deformation 37

2.6 Summary 43

References 44

Problems and Questions 45

 

3 A Survey of Engineering Materials 47

3.1 Introduction 47

3.2 Alloying and Processing of Metals 48

3.3 Irons and Steels 54

3.4 Nonferrous Metals 62

3.5 Polymers 66

3.6 Ceramics and Glasses 76

3.7 Composite Materials 82

3.8 Materials Selection for Engineering Components 87

3.9 Summary 93

References 95

Problems and Questions 96

 

4 Mechanical Testing: Tension Test and Other Basic Tests 100

4.1 Introduction 100

4.2 Introduction to Tension Test 105

4.3 Engineering Stress—Strain Properties 110

4.4 Trends in Tensile Behavior 119

4.5 True Stress—Strain Interpretation of Tension Test 125

4.6 Compression Test 133

4.7 Hardness Tests 139

4.8 Notch-Impact Tests 146

4.9 Bending and Torsion Tests 151

4.10 Summary 157

References 158

Problems and Questions 159

 

5 Stress—Strain Relationships and Behavior 172

5.1 Introduction 172

5.2 Models for Deformation Behavior 173

5.3 Elastic Deformation 183

5.4 Anisotropic Materials 196

5.5 Summary 205

References 207

Problems and Questions 207

 

6 Review of Complex and Principal States of Stress and Strain 216

6.1 Introduction 216

6.2 Plane Stress 217

6.3 Principal Stresses and the Maximum Shear Stress 227

6.4 Three-Dimensional States of Stress 235

6.5 Stresses on the Octahedral Planes 242

6.6 Complex States of Strain 244

6.7 Summary 249

References 251

Problems and Questions 251

 

7 Yielding and Fracture under Combined Stresses 257

7.1 Introduction 257

7.2 General Form of Failure Criteria 259

7.3 Maximum Normal Stress Fracture Criterion 261

7.4 Maximum Shear Stress Yield Criterion 264

7.5 Octahedral Shear Stress Yield Criterion 270

7.6 Discussion of the Basic Failure Criteria 277

7.7 Coulomb—Mohr Fracture Criterion 283

7.8 Modified Mohr Fracture Criterion 293

7.9 Additional Comments on Failure Criteria 300

7.10 Summary 303

References 304

Problems and Questions 305

 

8 Fracture of Cracked Members 316

8.1 Introduction 316

8.2 Preliminary Discussion 319

8.3 Mathematical Concepts 326

8.4 Application of K to Design and Analysis 330

8.5 Additional Topics on Application of K 341

8.6 Fracture Toughness Values and Trends 353

8.7 Plastic Zone Size, and Plasticity Limitations on LEFM 363

8.8 Discussion of Fracture Toughness Testing 372

8.9 Extensions of Fracture Mechanics Beyond Linear Elasticity 373

8.10 Summary 380

References 383

Problems and Questions 384

 

9 Fatigue of Materials: Introduction and Stress-Based Approach 398

9.1 Introduction 398

9.2 Definitions and Concepts 400

9.3 Sources of Cyclic Loading 411

9.4 Fatigue Testing 412

9.5 The Physical Nature of Fatigue Damage 417

9.6 Trends in S-N Curves 423

9.7 Mean Stresses 433

9.8 Multiaxial Stresses 445

9.9 Variable Amplitude Loading 450

9.10 Summary 460

References 461

Problems and Questions 463

 

10 Stress-Based Approach to Fatigue: Notched Members 473

10.1 Introduction 473

10.2 Notch Effects 475

10.3 Notch Sensitivity and Empirical Estimates of k f 479

10.4 Estimating Long-Life Fatigue Strengths (Fatigue Limits) 483

10.5 Notch Effects at Intermediate and Short Lives 488

10.6 Combined Effects of Notches and Mean Stress 492

10.7 Estimating S-N Curves 502

10.8 Use of Component S-N Data 509

10.9 Designing to Avoid Fatigue Failure 518

10.10 Discussion 523

10.11 Summary 524

References 526

Problems and Questions 527

 

11 Fatigue Crack Growth 542

11.1 Introduction 542

11.2 Preliminary Discussion 543

11.3 Fatigue Crack Growth Rate Testing 551

11.4 Effects of R = Smin/ Smax on Fatigue Crack Growth 556

11.5 Trends in Fatigue Crack Growth Behavior 566

11.6 Life Estimates for Constant Amplitude Loading 572

11.7 Life Estimates for Variable Amplitude Loading 583

11.8 Design Considerations 589

11.9 Plasticity Aspects and Limitations of LEFM for Fatigue Crack

Growth 591

11.10 Environmental Crack Growth 598

11.11 Summary 603

References 605

Problems and Questions 606

 

12 Plastic Deformation Behavior and Models for Materials 620

12.1 Introduction 620

12.2 Stress—Strain Curves 623

12.3 Three-Dimensional Stress—Strain Relationships 631

12.4 Unloading and Cyclic Loading Behavior from Rheological

Models 641

12.5 Cyclic Stress—Strain Behavior of Real Materials 650

12.6 Summary 663

References 665

Problems and Questions 666

 

13 Stress—Strain Analysis of Plastically Deforming Members 675

13.1 Introduction 675

13.2 Plasticity in Bending 676

13.3 Residual Stresses and Strains for Bending 685

13.4 Plasticity of Circular Shafts in Torsion 689

13.5 Notched Members 692

13.6 Cyclic Loading 704

13.7 Summary 715

References 716

Problems and Questions 717

 

14 Strain-Based Approach to Fatigue 727

14.1 Introduction 727

14.2 Strain Versus Life Curves 730

14.3 Mean Stress Effects 740

14.4 Multiaxial Stress Effects 749

14.5 Life Estimates for Structural Components 753

14.6 Discussion 763

14.7 Summary 771

References 772

Problems and Questions 773

 

15 Time-Dependent Behavior: Creep and Damping 784

15.1 Introduction 784

15.2 Creep Testing 786

15.3 Physical Mechanisms of Creep 791

15.4 Time—Temperature Parameters and Life Estimates 803

15.5 Creep Failure under Varying Stress 815

15.6 Stress—Strain—Time Relationships 818

15.7 Creep Deformation under Varying Stress 823

15.8 Creep Deformation under Multiaxial Stress 830

15.9 Component Stress—Strain Analysis 832

15.10 Energy Dissipation (Damping) in Materials 837

15.11 Summary 846

References 849

Problems and Questions 850

 

Appendix A Review of Selected Topics from Mechanics of Materials 862

A.1 Introduction 862

A.2 Basic Formulas for Stresses and Deflections 862

A.3 Properties of Areas 864

A.4 Shears, Moments, and Deflections in Beams 866

A.5 Stresses in Pressure Vessels, Tubes, and Discs 866

A.6 Elastic Stress Concentration Factors for Notches 871

A.7 Fully Plastic Yielding Loads 872

References 881

 

Appendix B Statistical Variation in Materials Properties 882

B.1 Introduction 882

B.2 Mean and Standard Deviation 882

B.3 Normal or Gaussian Distribution 884

B.4 Typical Variation in Materials Properties 887

B.5 One-Sided Tolerance Limits 887

B.6 Discussion 889

References 890

 

ANSWERS FOR SELECTED PROBLEMS AND QUESTIONS 891

BIBLIOGRAPHY 903

INDEX 916