Mechanics of Materials /

Incluye Referencias Bibliográficas

Stress

1.1 Introduction 1

1.2 Equilibrium of a Deformable Body 2

1.3 Stress 21

1.4 Average Normal Stress in an Axially Loaded Bar

26

1.5 Average Shear Stress 34

2

1.6 Allowable Stress 47

1.7 Design of Simple Connections 48

Strain

3

2.1 Deformation 65

2.2 Strain 66

Mechanical Properties of Materials

3.1 The Tension and Compression Test 79

3.2 The Stress-Strain Diagram 81

3.3 Stress-Strain Behavior of Ductile and Brittle Materials 85

65

79

3.4 Hooke's Law 88

3.5 Strain Energy 90

3.6 Poisson's Ratio 99

3.7 The Shear Stress-Strain Diagram 101

3.8 Failure of Materials Due to Creep and Fatigue 104

ix

Axial Load

5

4.1 Saint-Venant's Principle 111

4.2 Elastic Deformation of an Axially Loaded Member 114

4.3 Principle of Superposition 127

4.4 Statically Indeterminate Axially Loaded Member

4.5 Thermal Stress 142

4.6 Stress Concentrations 151

*4.7 Inclastic Axial Deformation 156

*4.8 Residual Stress 161

128

Torsion

5.1 Torsional Deformation of a Circular Shaft 171

5.2 The Torsion Formula 174

5.3 Power Transmission 183

5.4 Angle of Twist 192

5.5 Statically Indeterminate Torque-Loaded Member 205

*5.6 Solid Noncircular Shafts 214

*5.7 Thin-Walled Tubes Having Closed Cross Sections 217

5.8 Stress Concentration 229

*5.9 Inelastic Torsion 232

5.10 Residual Stress 239

Bending

247

6.1 Bending Deformation of a Straight Member

247

6.2 The Flexure Formula 252

6.3 Unsymmetric Bending 268

*6.4 Composite Beams 281

*6.5 Curved Beams 288.

6.6 Stress Concentrations 298

*6.7 Inelastic Bending 307

*6.8 Residual Stress 316

Transverse Shear

7.1 Shear in Straight Members 325

7.2 Differential Relationships Between Load, Shear, and Moment 328

7.3 The Shear Formula 330

7.4 Shear Stresses in Beams 332 7.5 Shear Flow in Built Members 346

7,6 Shear Flow in Thin-Walled Members 353

*7.7 Shear Center 360

325

8

Combined Loadings

8.1 Thin-Walled Pressure Vessels 373

8.2 State of Stress Caused by Combined Loadings 379

9

Stress Transformation

9.1 Plane-Suess Transformation 399

10

47

9.2 General Equations of Plane-Stress Transformation 408

9.3 Principal Stresses and Maximum In-Plane Shear Stress 410

9.4 Mohr's Circle-Plane Stress 424

9.5 Absolute Maximum Shear Stress 438.

Strain Transformation

373

10.1 Plane Strain 449

10.2 General Equations of Plane-Strain Transformation 451

10.3 Mohr's Circle-Plane Strain 458

10.4 Absolute Maximum Shear Strain 467

10.5 Strain Rosettes 470

10.6 Material-Property Relationships 474

*10,7 Theories of Failure 486

Mechanics of materials is a branch of mechanics that develops relationships between the external loads applied to a deformable body and the intensity of internal forces acting within the body. This subject is also concerned with computing the deformations of the body, and it provides a study of the body's stability when the body is subjected to external forces.

In the design of any structure or machine, it is first necessary to use the principles of statics to determine the forces acting both on and within its various members. Furthermore, the size of the members, their deflection, and their stability depend not only on these internal loadings, but also on the nature of the material from which the members are made. As a result, an accurate determination and fundamental understanding of material behavior is of vital importance to the development of the necessary equations used in mechanics of materials. Here we will not be interested in the specific details of experimental methods. Instead, we will state the experimental results and explain how they are used. Realize that many formulas and rules for design, as defined in engineering codes, are based on the fundamentals of mechanics of materials, and for this reason an understanding of the principles of this subject is very important.