Advance Steel Design

278 Index

material characteristics, 132 mooring lines
stress–strain curve, 131 steel chain, 231
steel wire ropes, 232
H synthetic ropes, 232

Hooke’s law, 51 mooring systems
catenary, 232
I taut, 232
turret, 232–3, 232
instability, 8, 134, 135, 138, 139, 231, 235, 245
intrados, 36, 40 N

J new-generation offshore platforms, 5–9
Newmark’s equation, 96
jet fire, 112–13 non-uniplanar bending, see unsymmetrical

K bending
NORSOK, 120
kinematic theorem, 66–8, 76 numerical model
kinetic energy, 121–2
BLSRP, 263–4
L triceratops, 239, 240, 258–63

lateral load functions O
concentrated load, 164–7
under uniformly distributed load, 159–63 offshore deck plate, behaviour of, 116–18
offshore platforms, 113, 122
lateral motion, 234, 238
lateral–torsional buckling (LTB), 135, 137, complaint, 2–5
energy absorption, 122–4
138, 138 new-generation, 5–9
L’Hospital rule, 154, 162, 163, 167 steel deck, 116–18
Liapunov’s condition, 134
linear elastic method, 119 P
load carrying capacity, 49, 65, 133–5
load–deformation relationship, 124, 135 plastic analysis
lower bound theorem, see static theorem advantages, 74
assumptions, 51–2
M disadvantages, 74
structures of, 51
Mathieu equation, 231, 233–6 theorems, 66, 68
Floquet theorem, 233
formulation of, 236–8 plastics, design of
Galerkin method, 234 collapse load estimation, 68–74
mathematical model, 238–9 kinematic theorem, 66–8
perturbation method, 236 mechanism, 65–6
moment curvature relationship, 63–5
Mathieu extended stability chart, 239 shape factors, 54–8
Mathieu instability, 235 static theorem, 66
Mathieu parameters, 233, 235, 236, 238 uniqueness theorem, 68
Mathieu stability, 231, 234, 234, 235
plastic, structural behaviour, 49–54
BLSRP, 248–58 pool fire, 111–12
compliant structures, 234–5 pressure vessel explosion (PVE), 93–4
eccentric loading, 255–7, 255–8, 257 pressure waves (P-waves), 94, 95
numerical model, 248–9 PVE, see pressure vessel explosion (PVE)
tether pullout, 250–5, 254
tether stiffness, 245–6, 246 R
triceratops, 235–9
moment curvature relationship, 63–5 recentering, 5, 134, 231
rectangular section, 54–5
reserve strength, 49

Index 279

S T

shape factor, 54, 58 taut-moored tethers, 4, 7, 8
shape factor, MATLAB code, 58–61 taut mooring systems, 232
shared-energy design, 121 tensile axial load, 163–4
ship-platform collision, 89, 120–2 tension buoyant tower, 5
shock waves (S-waves), 94, 95 tension leg platform (TLP), 2, 4–7, 133, 134,
stability, 1–2, 136
231, 232, 235, 248
buckling and instability, 134–9 tethers
conditions of, 133–4
criteria of, 133 lateral motion, 234, 238
failures of, 2 TLP, see tension leg platform (TLP)
functions, 150–8, 218–29 torsional buckling (TB), 135, 136
illustrations, 136 toughness, 1
structural system, 1 triangular section, 55–7, 56
stability analysis, exercise problems, triceratops, 6–7, 7, 124, 234, 239,

168–201 242, 243
stability parameters, influence of, buoyant legs, impact analysis, 124–9
numerical model, 239, 240, 258–63
239–48 turret-mooring system, 232, 232, 232–3
increased payload, 246–8, 247, 248
tether stiffness, 245, 245–6, 246 U
water depth, 243–5, 244, 244
wave height, 239–42 uniqueness theorem, 68
wave period, 242–3 unsymmetrical bending, 15–20
standard beam element, 141–50, 142 upper bound theorem, see kinematic theorem
degree of freedom, 142
rotational coefficients, 147–50 V
stiffness coefficients, 143
static theorem, 66, 75 vapor cloud explosion (VCE), 92–3
steel, 1, 50, 114 Von-Mises yield criteria, 117
at high temperature, 114–16
stress-strain curve, 49 W
stiffened cylinders, design of, 9–15
buckling modes, 9 Winkler Bach equation, 40
classification of, 9
stiffeners, 9 Y
strength design, 121
stress–strain curve, 49 Young’s modulus, 119, 120, 124, 132
stress–strain relationship, 2, 119
stringers, 9 Z
structural systems, 231
buckling load, 201–29 zero axial loads, 154, 157, 162, 167
examples of, 231 zone method, 119
stability, 1–2, 133–4