Hearn Mechanics of Materials Volume 1

An Introduction to the Mechanics of Elastic and Plastic Deformation of Solids and Structural Materials
3. Auflage 1997
ISBN: 978-0-08-052399-6
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 450 Seiten

One of the most important subjects for any student of engineering to master is the behaviour of materials and structures under load. The way in which they react to applied forces, the deflections resulting and the stresses and strains set up in the bodies concerned are all vital considerations when designing a mechanical component such that it will not fail under predicted load during its service lifetime.
All the essential elements of a treatment of these topics are contained within this course of study, starting with an introduction to the concepts of stress and strain, shear force and bending moments and moving on to the examination of bending, shear and torsion in elements such as beams, cylinders, shells and springs. A simple treatment of complex stress and complex strain leads to a study of the theories of elastic failure and an introduction to the experimental methods of stress and strain analysis.
More advanced topics are dealt with in a companion volume - Mechanics of Materials 2. Each chapter contains a summary of the essential formulae which are developed in the chapter, and a large number of worked examples which progress in level of difficulty as the principles are enlarged upon. In addition, each chapter concludes with an extensive selection of problems for solution by the student, mostly examination questions from professional and academic bodies, which are graded according to difficulty and furnished with answers at the end.
* Emphasis on practical learning and applications, rather than theory
* Provides the essential formulae for each individual chapter
* Contains numerous worked examples and problems

Autoren/Hrsg.

Hearn, E. J.

Inhaltsverzeichnis

1;Cover;1
2;Mechanics of Materials 1;4
3;Copyright Page;5
4;Contents;6
5;Introduction;16
6;Notation;18
7;Chapter 1. Simple Stress and Strain;22
7.1;1.1 Load;22
7.2;1.2 Direct or normal stress ( s );23
7.3;1.3 Direct strain ( e );23
7.4;1.4 Sign convention for direct stress and strain;23
7.5;1.5 Elastic materials – Hooke's law;24
7.6;1.6 Modulus of elasticity – Young's modulus;24
7.7;1.7 Tensile test;25
7.8;1.8 Ductile materials;29
7.9;1.9 Brittle materials;29
7.10;1.10 Poisson's ratio;30
7.11;1.11 Application of Poisson's ratio to a two-dimensional stress system;31
7.12;1.12 Shear stress;32
7.13;1.13 Shear strain;32
7.14;1.14 Modulus of rioidity;33
7.15;1.15 Double shear;33
7.16;1.16 Allowable workino stress – factor of safety;33
7.17;1.17 Load factor;34
7.18;1.18 Temperature stresses;34
7.19;1.19 Stress concentrations – stress concentration factor;35
7.20;1.20 Toughness;35
7.21;1.21 Creep and fatigue;36
7.22;Examples;38
7.23;Problems;46
7.24;Bibliography;47
8;Chapter 2. Compound Bars;48
8.1;Summary;48
8.2;2.1 Compound bars subjected to external load;49
8.3;2.2 Compound bars- "equivalent" or "combined" modulus;50
8.4;2.3 Compound bars subjected to temperature change;51
8.5;2.4 Compound bar (tube and rod);53
8.6;2.5 Compound bars subjected to external load and temperature effects;55
8.7;2.6 Compound thick cylinders subjected to temperature changes;55
8.8;Examples;55
8.9;Problems;60
9;Chapter 3. Shearing Force and Bending Moment Diagrams;62
9.1;Summary;62
9.2;3.1 Shearing force and bending moment;62
9.3;3.2 S.F. and B.M. diagrams for beams carrying concentrated loads only;64
9.4;3.3 S.F and B.M. diagrams for uniformly distributed loads;67
9.5;3.4 S.F. and B.M. diagrams for combined concentrated and uniformly distributed loads;68
9.6;3.5 Points of contraflexure;69
9.7;3.6 Relationship between S.F. Q, B.M. M, and intensity of loading w;70
9.8;3.7 S.F. and B.M. diagrams for an applied couple or moment;71
9.9;3.8 S.F. and B.M. diagrams for inclined loads;73
9.10;3.9 Graphical construction of S.F and B.M. diagrams;75
9.11;3.10 S.F. and B.M. diagrams for beams carrying distributed loads of increasing value;76
9.12;3.11 S.F. at points of application of concentrated loads;76
9.13;Examples;77
9.14;Problems;80
10;Chapter 4. Bending;83
10.1;Summary;83
10.2;Introduction;84
10.3;4.1 Simple bending theory;85
10.4;4.2 Neutral axis;87
10.5;4.3 Section modulus;89
10.6;4.4 Second moment of area;89
10.7;4.5 Bending of composite or flitched beams;91
10.8;4.6 Reinforced concrete beams – simple tension reinforcement;92
10.9;4.7 Skew loading;94
10.10;4.8 Combined bending and direct stress–eccentric loading ;95
10.11;4.9 "Middle-quarter" and "middle-third" rules ;97
10.12;4.10 Shear stresses owing to bending;98
10.13;4.11 Strain energy in bending;99
10.14;4.12 Limitations of the simple bending theory;99
10.15;Examples;100
10.16;Problems;109
11;Chapter 5. Slope and Deflection of Beams;113
11.1;Summary;113
11.2;Introduction;115
11.3;5.1 Relationship between loading, S.F., B.M., slope and deflection;115
11.4;5.2 Direct integration method;118
11.5;5.3 Macaulay's method;123
11.6;5.4 Macaulay's method for u.d.l's;126
11.7;5.5 Macaulay's method for beams with u.d.l, applied over part of the beam;127
11.8;5.6 Macaulay's method for couple applied at a point;127
11.9;5.7 Mohr 's "area–moment" method;129
11.10;5.8 Principle of superposition;133
11.11;5.9 Energy method;133
11.12;5.10 Maxwell 's theorem of reciprocal displacements;133
11.13;5.11 Continuous beams – Clapeyron 's "three-moment" equation;136
11.14;5.12 Finite difference method;139
11.15;5.13 Deflections due to temperature effects;140
11.16;Examples;144
11.17;Problems;159
12;Chapter 6. Built-in Beams;161
12.1;Summary;161
12.2;Introduction;162
12.3;6.1 Built-in beam carrying central concentrated load;162
12.4;6.2 Built-in beam carrying uniformly distributed load across the span;163
12.5;6.3 Built-in beam carrying concentrated load offset from the centre;164
12.6;6.4 Built-in beam carrying a non-uniform distributed load;166
12.7;6.5 Advantages and disadvantages of built-in beams;167
12.8;6.6 Effect of movement of supports;167
12.9;Examples;168
12.10;Problems;173
13;Chapter 7. Shear Stress Distribution;175
13.1;Summary;175
13.2;Introduction;176
13.3;7.1 Distribution of shear stress due to bending;177
13.4;7.2 Application to rectangular sections;178
13.5;7.3 Application to I-section beams;179
13.6;7.4 Application to circular sections;183
13.7;7.5 Limitation of shear stress distribution theory;185
13.8;7.6 Shear centre;186
13.9;Examples;187
13.10;Problems;194
14;Chapter 8. Torsion;197
14.1;Summary;197
14.2;8.1 Simple torsion theory;198
14.3;8.2 Polar second moment of area;200
14.4;8.3 Shear stress and shear strain in shafts;201
14.5;8.4 Section modulus;202
14.6;8.5 Torsional rigidity;203
14.7;8.6 Torsion of hollow shafts;203
14.8;8.7 Torsion of thin-walled tubes;203
14.9;8.8 Composite shafts–series connection;203
14.10;8.9 Composite shafts–parallel connection;204
14.11;8.10 Principal stresses;205
14.12;8.11 Strain energy in torsion;205
14.13;8.12 Variation of data along shaft length–torsion of tapered shafts;207
14.14;8.13 Power transmitted by shafts;207
14.15;8.14 Combined stress systems – combined bending and torsion;208
14.16;8.15 Combined bending and torsion–equivalent bending moment;208
14.17;8.16 Combined bending and torsion – equivalent torque;209
14.18;8.17 Combined bending, torsion and direct thrust;210
14.19;8.18 Combined bending, torque and internal pressure;210
14.20;Examples;211
14.21;Problems;216
15;Chapter 9. Thin Cylinders and Shells;219
15.1;Summary;219
15.2;9.1 Thin cylinders under internal pressure;219
15.3;9.2 Thin rotating ring or cylinder;222
15.4;9.3 Thin spherical shell under internal pressure;223
15.5;9.4 Vessels subjected to fluid pressure;224
15.6;9.5 Cylindrical vessel with hemispherical ends;225
15.7;9.6 Effects of end plates and joints;226
15.8;9.7 Wire-wound thin cylinders;227
15.9;Examples;229
15.10;Problems;234
16;Chapter 10. Thick cylinders;236
16.1;Summary;236
16.2;10.1 Difference in treatment between thin and thick cylinders – basic assumptions;237
16.3;10.2 Development of the Lamé theory;238
16.4;10.3 Thick cylinder – internal pressure only;240
16.5;10.4 Longitudinal stress;241
16.6;10.5 Maximum shear stress;242
16.7;10.6 Change of cylinder dimensions;242
16.8;10.7 Comparison with thin cylinder theory;243
16.9;10.8 Graphical treatment – Lamé line;244
16.10;10.9 Compound cylinders;245
16.11;10.10 Compound cylinders – graphical treatment;247
16.12;10.11 Shrinkage or interference allowance;247
16.13;10.12 Hub on solid shaft;250
16.14;10.13 Force fits;250
16.15;10.14 Compound cylinder – different materials;251
16.16;10.15 Uniform heating of compound cylinders of different materials;252
16.17;10.16 Failure theories – yield criteria;254
16.18;10.17 Plastic yielding – "auto-frettage";254
16.19;10.18 Wire–wound thick cylinders ;255
16.20;Examples;257
16.21;Problems;272
17;Chapter 11. Strain Energy;275
17.1;Summary;275
17.2;Introduction;277
17.3;11.1 Strain energy – tension or compression;278
17.4;11.2 Strainenergy–shear;280
17.5;11.3 Strain energy – bending;281
17.6;11.4 Strain energy – torsion;282
17.7;11.5 Strain energy of a three.dimensional principal stress system;283
17.8;11.6 Volumetric or dilatational strain energy;283
17.9;11.7 Shear or distortional strain energy;284
17.10;11.8 Suddenly applied loads;284
17.11;11.9 Impact loads–axial load application;285
17.12;11.10 Impact loads – bending applications;286
17.13;11.11 Castigliano's first theorem for deflection;287
17.14;11.12 "Unit-load" method ;289
17.15;11.13 Application of Castigliano's theorem to angular movements;290
17.16;11.14 Shear deflection ;290
17.17;Examples;295
17.18;Problems;313
18;Chapter 12. Springs;318
18.1;Summary;318
18.2;Introduction;320
18.3;12.1 Close-coiled helical spring subjected to axial load W;320
18.4;12.2 Close-coiled helical spring subjected to axial torque T;321
18.5;12.3 Open-coiled helical spring subjected to axial load W;322
18.6;12.4 Open-coiled helical spring subjected to axial torque T;325
18.7;12.5 Springs in series;326
18.8;12.6 Springs in parallel;327
18.9;12.7 Limitations of the simple theory;327
18.10;12.8 Extension springs – initial tension;328
18.11;12.9 Allowable stresses;329
18.12;12.10 Leaf or carriage spring: semi-elliptic;330
18.13;12.11 Leaf or carriage spring: quarter-elliptic;333
18.14;12.12 Spiral spring;335
18.15;Examples;337
18.16;Problems;345
19;Chapter 13. Complex Stresses;347
19.1;Summary;347
19.2;13.1 Stresses on oblique planes;347
19.3;13.2 Material subjected to pure shear;348
19.4;13.3 Material subjected to two mutually perpendicular direct stresses;350
19.5;13.4 Material subjected to combined direct and shear stresses;350
19.6;13.5 Principal plane inclination in terms of the associated principal stress;352
19.7;13.6 Graphical solution – Mohr's stress circle;353
19.8;13.7 Alternative representations of stress distributions at a point;355
19.9;13.8 Three-dimensional stresses–graphical representation;359
19.10;Examples;363
19.11;Problems;379
20;Chapter 14. Complex Strain and the Elastic Constants;382
20.1;Summary;382
20.2;14.1 Linear strain for tri-axial stress state;382
20.3;14.2 Principal strains in terms of stresses;383
20.4;14.3 Principal stresses in terms of strains – two-dimensional stress system;384
20.5;14.4 Bulk modulus K;384
20.6;14.5 Volumetric strain;384
20.7;14.6 Volumetric strain for unequal stresses;385
20.8;14.7 Change in volume of circular bar;386
20.9;14.8 Effect of lateral restraint;387
20.10;14.9 Relationship between the elastic constants E, G, K and v;388
20.11;14.10 Strains on an oblique plane;391
20.12;14.11 Principal strain – Mohr's strain circle;393
20.13;14.12 Mohr's strain circle – alternative derivation from the general stress equations;395
20.14;14.13 Relationship between Mohr's stress and strain circles;396
20.15;14.14 Construction of strain circle from three known strains (McClintock method) –rosette analysis;399
20.16;14.15 Analytical determination of principal strains from rosette readings;402
20.17;14.16 Alternative representations of strain distributions at a point;404
20.18;14.17 Strain energy of three-dimensional stress system;406
20.19;Examples;408
20.20;Problems;418
21;Chapter 15. Theories of Elastic Failure;422
21.1;Summary;422
21.2;Introduction;422
21.3;15.1 Maximum principal stress theory;423
21.4;15.2 Maximum shear stress theory;424
21.5;15.3 Maximum principal strain theory;424
21.6;15.4 Maximum total strain eneroy per unit volume theory;424
21.7;15.5 Maximum shear strain energy per unit volume (or distortion energy) theory;424
21.8;15.6 Mohr's modified shear stress theory for brittle materials;425
21.9;15.7 Graphical representation of failure theories for two-dimensional stress systems (one principal stress zero);427
21.10;15.8 Graphical solution of two-dimensional theory of failure problems;431
21.11;15.9 Graphical representation of the failure theories for three-dimensional stress systems;432
21.12;15.10 Limitations of the failure theories;434
21.13;15.11 Effect of stress concentrations;435
21.14;15.12 Safety factors;435
21.15;15.13 Modes of failure;437
21.16;Examples;438
21.17;Problems;448
22;Chapter 16. Experimental Stress Analysis;451
22.1;Introduction;451
22.2;16.1 Brittle lacquers;452
22.3;16.2 Strain gauges;456
22.4;16.3 Unbalanced bridge circuit;458
22.5;16.4 Null balance or balanced bridge circuit;458
22.6;16.5 Gauge construction;458
22.7;16.6 Gauge selection;460
22.8;16.7 Temperature compensation;460
22.9;16.8 Installation procedure;461
22.10;16.9 Basic measurement systems;462
22.11;16.10 D.C. and A.C. systems;464
22.12;16.11 Other types of strain gauge ;465
22.13;16.12 Photoelasticity;466
22.14;16.13 Plane-polarised light– basic polariscope arrangements;467
22.15;16.14 Temporary birefringence;467
22.16;16.15 Production of fringe pattern;469
22.17;16.16 Interpretation of fringe patterns ;470
22.18;16.17 Calibration;471
22.19;16.18 Fractional fringe order determination – compensation techniques;472
22.20;16.19 Isoclinics – circular polarisation;473
22.21;16.20 Stress separation procedures;475
22.22;16.21 Three-dimensional photoelasticity;475
22.23;16.22 Reflective coating technique;475
22.24;16.23 Other methods of strain measurement;477
22.25;Bibliography;477
23;Appendix 1. Typical mechanical and physical properties for engineering materials;478
24;Appendix 2. Typical mechanical properties of non-metals ;479
25;Appendix 3. Other properties of non-metals ;480
26;Index;482