G. F. C. Searle (1864–1954) was a British physicist who made notable contributions to the development of laboratory physics and theories of electromagnetic mass. First published in 1933, as the second edition of a 1908 original, this book was based on the manuscript notes prepared by Searle for the use of students attending his practical physics classes at the Cavendish Laboratory, Cambridge. The first chapter contains an account of the elements of the mathematical theory of elastics; the second chapter provides mathematical solutions for some simple elastic problems which regularly appear in experiments; the third chapter contains descriptions of a number of experiments together with such necessary mathematical discussions as are not given in the first two chapters. This book will be of value to anyone with an interest in experimental physics and the pedagogy of physics.

CHAPTER I

ELEMENTARY THEORY OF ELASTICITY

1 Introduction 1

2 Hooke'sLaw 2

3 Necessity for a theory of elasticity 2

4 Action and reaction between two parts of a body 3

5 Stress 5

6 Measurement of stresses 5

7 Hydrostatic pressure 6

8 Strain. 7

9 Expansion and compression 7

10 Shear. 8

11 Maximum shear in actual experiments 9

12 Results for infinitesimal shears 9

13 Bulk modulus or volume elasticity 10

14 Rigidity 11

15 Stresses on the diagonal planes of a sheared cube 13

16 Alternative method of producing as hear 14

17 Young's modulus 15

18 Poisson's ratio 17

19 Relations between elastic constants. 18

20 Isothermal and adiabatic elasticities 20

21 Ratio of adiabatic to isothermal elasticity 22

22 Difference between reciprocals of isothermal and adiabatic elasticities 25

CHAPTER II SOLUTIONS OF SOME SIMPLE ELASTIC PROBLEMS

23 Practical applications of the theory of elasticity 30

24 Principle of Saint-Venant. 31

25 Dr Filon's results for tension 32

26 Dr Filon's results for torsion 36

UNIFORM BENDING OF A RoD

27 Introduction 38

28 Strain and stress in a uniformly bent rod 39

29 Change of cross-section due to bending 40

30 Position of the neutral flament 46

3l Bending moment 47

32 Removal of the“body forces”. 48

33 Case of a rod 49

34 Case of a blade. 50

UNIFORM BENDING OF A BLADE

35 Introduction 52

36 Position of neutral f laments 54

37 Bending moment 56

38 Change of type of bending 57

UNIFORM TORSION OF ARoUND RoD

39 Relation between torsional couple and twist 58

40 Rods of non-circular section 60

41 Practical approximation 62

UNIFORM TORSION OF A BLADE

42 Introduction 63

43 Geometry of a heli co id 63

44 Stresses in a twisted blade 66

45 Determination of the torsional couple 68

CHAPTER III EXPERIMENTAL WORK IN ELASTICITY

46 Introduction 71

Experiment 1. Experimental investigation of Hooke'slaw for copper

47 Introduction 72

48 Apparatus 74

49 Experiments on loading and unloading a copper wire 77

50 Graphical representation of deviations from Hooke'slaw 78

51 Practical example 79

Bx periment 2.Determination of Young's modulus by stretching a vertical wire

52 Apparatus 80

53 Determination of Young's modulus 81

54 Practical example 85

Experiment 3. Determination of Young's modulus by stretching a horizontal wire

55 Apparatus 86

56 Determination of Young's modulus 87

57 Notes on the method 88

58 Practical example 89

Experiment 4. Determination of rigidity Static al method

59 Apparatus 90

60 Determination of rigidity 91

61 Practical example 94

Experiment 5. Determination of rigidity Dynamical method

62 Apparatus 95

63 Determination of rigidity 97

64 Practical example 99

Experiment 6. Determination of Young's modulus by

uniform bending of a rod. Static al method

65 Apparatus 100

66 Determination of Young's modulus. 102

67 Mirror method of determining curvature. 104

68 Practical example 106

Experiment 7. Determination of Young's modulus by uniform bending of a rod Dynamical method

69 Determination of Young's modulus. 107

70 Experimental details. 110

71 Practical example 111

E periment 8. Comparison of elastic constants Dynamical method

72 Method 112

73 Practical er ample 114

Experiment 9. Determination of Poisson's ratio by the bending of a rectangular rod

74 Introduction 114

75 Determination of Poisson's ratio 118

76 Practical example 119

Experiment 10. Determination of Young's modulus by non-uniform bending of a rod

77 Introduction 119

78 Approximate results for non-uniform bending. 121

79 Cartesian expression for curvature 124

80 Apparatus. 126

81 Depression at centre of rod 127

82 Slope at end of rod. 129

83 Determination of Young's modulus 130

84 Practical example 131

85 Introduction 132

86 Determination of rigidity 132

87 Practical exar ple 134

Experiment 12. Determination of E/(1-2) by the uniform bending of a blade

88 Introduction 135

89 Apparatus 136

90 Determination of E(1-0') 138

91 Calculation of E and of o 139

92 Practical example 139

Experiment 13. Test of Lord Rayleigh's reciprocal relations

93 Introduction 141

94 Work done by forces. 143

95 Lord Rayleigh's reciprocal relations 145

96 Apparatus 147

97 Test of first reciprocal relation. 148

98 Test of third reciprocal relation 149

99 Practical example 150

Experiment 14.Measurement of the energy dissipated through torsional hysteresis

100 Introduction 152

101 Energy dissipated per cycle 154

102 Apparatus 155

103 Experimental details 157

104 Practical example 159

Note I. Reduction of a group of forces to a single force and a couple. 162

Note II. D'Alembert's principle 162

Note III. Motion of a rigid body

      1 Acceleration of the centre of gravity 163

      2 Angular acceleration of a rigid body turning about afx ed axis 164

Note IV. Moments of inertia

      1 Definition 165

      2 Some properties of moments of inertia 165

      3 Theorem of parallel axes 166

      4 Moments of inertia of a thin rod 166

      5 Moments of inertia of a rectangular lamina 167

      6 Moments of inertia of a rectangular block 167

      7 Moments of inertia of a circular lamina 167

      8 Moments of inertia of an elliptical lamina 168

      9 Moment of inertia of a sphere 168

      10 Moments of inertia of an ellipsoid 168

      11 Moments of inertia of a circular cylinder. 169

      12 “Moments of inertia”of areas. 169

      13 Angular momentum of a rigid body turning about afx edaxis. 170

      14 Kinetic energy of a rigid body turning about an xed axis 170

Note V. Harmonic motion

      1 Rectilinear motion 171

      2 Motion about a fixed axis. 172

Note VI. Corrections for variations in the radius of a wire

      1 Young's modulus. 172

      2 Rigidity 173

Note VII. On inertia bars 174

Note VIII. Work done by a couple 175

Note IX. Trapezoidal rule for the measurement of areas 176

Not eX. Hints on practical work in physics

      1 Failures 178

      2 Observations 178

      3 The recording of observations 179

      4 Arithmetical reduction of observations 180

      5 Diagram 8 182

      6 Notebooks. 182

      7 General remarks. 182

Note XI. Maximum elevation at centre of rodin ExPERIMENT 184

Not eXIL Theory of infinitesimal uniform bending of a rod 184

INDEX 187

中科院文献情报中心