Srinivasan Chandrasekaran - Offshore Compliant Platforms

2 Chapter 2Figure 2.1 Schematic diagram of the BLSRP installed in a wave flume.Figure 2.2 Experimental setup and arrangements: (a) side view; (b) hinged jo...Figure 2.3 Orientation of the BLSRP for the wave heading angle.Figure 2.4 Response of the BLSRP (0°, 0.1 m wave height).Figure 2.5 Numerical model of the BLSRP.Figure 2.6 Response of the BLSRP (30°, 15 m).Figure 2.7 Tether tension variations in mooring lines.Figure 2.8 Power spectral density plots of buoyant leg 1 (0°, 6 m, 10 second...Figure 2.9 Power spectral density plots of the deck (0°, 6 m, 10 seconds).Figure 2.10 Numerical model of the BLSRP (normal case).Figure 2.11 Numerical model of the BLSRP with postulated failure.Figure 2.12 Dynamic tether tension variation in postulated failure cases.Figure 2.13 Mathieu stability for the BLSRP in postulated failure cases.

3 Chapter 3Figure 3.1 Typical regular wave profile (H = 2 m, T = 5 s).Figure 3.2 PM spectrum for different sea conditions.Figure 3.3 Two‐dimensional random wave profile (Wang and Isberg 2015).Figure 3.4 API spectrum plot for different wind velocities.Figure 3.5 Wind‐generated current velocity profile.Figure 3.6 Service life estimation methodology.Figure 3.7 Triceratops model.Figure 3.8 Experimental model of a stiffened triceratops.Figure 3.9 Plan of the triceratops.Figure 3.10 RAOs of the deck and buoyant legs with regular waves.Figure 3.11 Deck response given different wave heading angles.Figure 3.12 Tether tension variation in rough sea conditions.Figure 3.13 Deck surge and heave PSD plots in very high sea conditions.Figure 3.14 Pitch response of the deck and buoyant legs in very high sea con...Figure 3.15 Maximum deck response in very high sea conditions.Figure 3.16 Tether tension spectrum with very high sea conditions.Figure 3.17 Maximum tether tension in very high sea conditions.Figure 3.18 Deck response with high sea conditions (w – waves, w + w – waves...Figure 3.19 Phase plots in the surge DOF with very high sea conditions.Figure 3.20 Buoyant leg response with high sea conditions.Figure 3.21 Tension spectrum with very high sea conditions.

4 Chapter 4Figure 4.1 Random ice force and vibration of the structure.Figure 4.2 True stress–strain curve of AH36 grade steel.Figure 4.3 Different shapes of indenters.Figure 4.4 Time–temperature curves for different fire conditions.Figure 4.5 Reduction factors for yield strength, proportional limits, and li...Figure 4.6 Variations in the thermal conductivity of carbon steel.Figure 4.7 Variations in the specific heat of carbon steel.Figure 4.8 Variations in the thermal strain of carbon steel.Figure 4.9 Spectral density plot given different ice velocities.Figure 4.10 Spectral density plot given different ice forces.Figure 4.11 Ice force–time history.Figure 4.12 PSD plots for normal ice sea conditions with ice load on two buo...Figure 4.13 PSD plots of tether tension variation in normal sea conditions....Figure 4.14 Total deck response for different ice thicknesses.Figure 4.15 Total deck response for different ice crushing strengths.Figure 4.16 Total deck response for different ice velocities.Figure 4.17 PSD plots of the deck in open water and ice‐covered load cases....Figure 4.18 Methodology of impact analysis.Figure 4.19 Numerical model of buoyant legs and indenters.Figure 4.20 Force versus nondimensional deformation curve.Figure 4.21 Deck surge responses for impact loads on buoyant leg 1.Figure 4.22 Force–deformation curves for different indenter sizes.Figure 4.23 Force–deformation curves for different impact locations.Figure 4.24 Force–deformation curves for different indenter shapes.Figure 4.25 Force–deformation curves for different numbers of stringers.Figure 4.26 Force–deformation curve of buoyant legs at different temperature...Figure 4.27 Deck plate of a triceratops.Figure 4.28 Scale deck plate model.Figure 4.29 Hydrocarbon fire cases.Figure 4.30 Temperature variations in plates and stiffeners.

5 Chapter 5Figure 5.1 Numerical model of a triceratops with a wind turbine.Figure 5.2 Pitch RAO of the triceratops.Figure 5.3 PSD plot of the surge free‐decay response.Figure 5.4 PSD plot of the roll free‐decay response.Figure 5.5 Frequency response to operable and parked conditions.Figure 5.6 PSD plots for different DOF.Figure 5.7 Dynamic tether tension variation.Figure 5.8 Plan and elevation of a stiffened buoyant leg.Figure 5.9 Fabricated model of a stiffened buoyant leg.Figure 5.10 Fabricated model of a ball joint.Figure 5.11 Surge, heave, and pitch RAOs of the deck and buoyant legs with 0...Figure 5.12 Surge, heave, and pitch RAOs of the deck and buoyant legs with 9...Figure 5.13 Surge, heave, and pitch RAOs of the deck and buoyant legs with 1...Figure 5.14 Effect of wave direction on the stiffened triceratops.Figure 5.15 Cross section of the buoyant legs.Figure 5.16 Plan view of the triceratops with circular and elliptical buoyan...Figure 5.17 Total force–time history, given high sea conditions.

1 Cover

2 Table of Contents

3 Begin Reading

1 ii

2 iii

3 iv

4 ix

5 x

6 xi

7 xii

8 xiii

9 xiv

10 xv

11 xvii

12 xviii

13 xix

14 xxi

15 xxii

16 1

17 2

18 3

19 4

20 5

21 6

22 7

23 8

24 9

25 10

26 11

27 12

28 13

29 14

30 15

31 16

32 17

33 18

34 19

35 20

36 21

37 22

38 23

39 24

40 25

41 26

42 27

43 28

44 29

45 30

46 31

47 32

48 33

49 34

50 35

51 36

52 37

53 38

54 39

55 40

56 41

57 42

58 43

59 44

60 45

61 46

62 47

63 48

64 49

65 50

66 51

67 52

68 53

69 54

70 55

71 56

72 57

73 58

74 59

75 60

76 61

77 62

78 63

79 64

80 65

81 66

82 67

83 68

84 69

85 70

86 71

87 72

88 73

89 74

90 75

91 76

92 77

93 78

94 79

95 80

96 81

97 82

98 83

99 84

100 85

101 86

102 87

103 88

104 89

105 90

106 91

107 92

108 93

109 95

110 96

111 97

112 98

113 99

114 100

115 101

116 102

117 103

118 104

119 105

120 106

121 107

122 108

123 109

124 110

125 111

126 112

127 113

128 114

129 115

130 116

131 117

132 118

133 119

134 120

135 121

136 122

137 123

138 125

139 126

140 127

141 128

142 129

143 130

144 131

145 132

146 133

147 134

148 135

149 136

150 137

151 138

152 139

153 140

154 141

155 142

156 143

157 144

158 145

159 146

160 147

161 148

162 149

163 150

164 151

165 152

166 153

167 154

168 155

169 156

170 157

171 158

172 159

173 160

174 161

175 162

176 163

177 164

178 165

179 166

180 167

181 168

182 169

183 170

184 171

185 172

186 173

187 174

188 175

189 176

190 177

191 178

192 179

193 180

194 181

195 182

196 183

197 184

198 185

199 186

200 187

201 188

202 189

203 190

204 191

205 192

206 193

207 194

208 195

209 196

210 197

211 198

212 199

213 200

214 201

215 202

216 203

217 204

218 205

219 206