Page 15 - Marine Structural Design

xii Contents
13.6.2 Collapse of an Upper Deck Structure ............................................................................... 273
13.6.3 Collapse of Stiffened Box Girders ................................................................................... 274
13.6.4 Ultimate Longitudinal Strength of Hull Girders .............................................................. 276
13.6.5 Quasi-Static Analysis of a Side Collision ........................................................................ 278
13.7 Conclusions ............................................................................................................................. 279
13.8 References ............................................................................................................................... 280
CHAPTER 14 OFFSHORE STRUCTURES UNDER IMPACT LOADS .................................... 285
14.1 General ..................................................................................................................................... 285
14.2 Finite Element Formulation ..................................................................................................... 286
14.2.1 Equations of Motion ......................................................................................................... 286
14.2.2 Load-Displacement Relationship ofthe Hit Member ...................................................... 286
14.2.3 Beam-Column Element for Modeling of the Struck Structure ......................................... 287
14.2.4 Computational Procedure ................................................................................................. 287
14.3 Collision Mechanics ................................................................................................................ 289
14.3.1 Fundamental Principles .................................................................................................... 289
14.3.2 Conservation of Momentum ............................................................................................ 289
14.3.3 Conservation of Energy .................................................................................................... 290
14.4 Examples ................................................................................................................................. 291
14.4.1 Mathematical Equations for Impact Forces and Energies in ShiplPlafform Collisions ... 29 1
14.4.2 Basic Numerical Examples .............................................................................................. 292
14.4.3 Application to Practical Collision Problems .................................................................... 298
14.5 Conclusions ............................................................................................................................. 303
14.6 References ............................................................................................................................... 303
CHAPTER 15 OFFSHORE STRUCTURES UNDER EARTHQUAKE LOADS ....................... 305
15.1 General ..................................................................................................................................... 305
15.2 Earthquake Design as per API RP2A ...................................................................................... 305
15.3 Equations and Motion .............................................................................................................. 307
15.3.1 Equation of Motion .......................................................................................................... 307
15.3.2 Nonlinear Finite Element Model ...................................................................................... 308
15.3.3 Analysis Procedure ........................................................................................................... 308
15.4 Numerical Examples ................................................................................................................ 308
15.5 Conclusions ............................................................................................................................. 313
15.6 References ............................................................................................................................... 314

Part 111: Fatigue and Fracture
CHAPTER 16 MECHANISM OF FATIGUE AND FRACTURE ................................................ 317

16.1 Introduction ............................................................................................................................. 317
16.2 Fatigue Overview .................................................................................................................... 317
16.3 Stress-Controlled Fatigue ........................................................................................................ 318
16.4 Cumulative Damage for Variable Amplitude Loading ............................................................ 320
16.5 Strain-Controlled Fatigue ........................................................................................................ 321
16.6 Fracture Mechanics in Fatigue Analysis .................................................................................. 323
16.7 Examples ................................................................................................................................. 325
16.8 References ............................................................................................................................... 326
CHAPTER 17 FATIGUE CAPACITY ... ......................................................................................... 329
17.1 S-N Curves .............................................................................................................................. 329
17.1.1 General ............................................................................................................................. 329
17.1.2 Effect of Plate Thickness ................................................................................................. 33 1