Page 11 - Marine Structural Design

viii Contents
3.2 Environmental Conditions ......................................................................................................... 39
3.2.1 Environmental Criteria ....................................................................................................... 39
3.2.2 Regular Waves ................................................................................................................... 41
3.2.3 Irregular Waves .................................................................................................................. 41
3.2.4 Wave Scatter Diagram ....................................................................................................... 42
3.3 Environmental Loads and Floating Structure Dynamics ........................................................... 45
3.3.1 Environmental Loads ......................................................................................................... 45
3.3.2 Sea loads on Slender Structures ......................................................................................... 45
3.3.3 Sea loads on Large-Volume Structures .............................................................................. 45
3.3.4 Floating Structure Dynamics .............................................................................................. 46
3.4 Structural Response Analysis .................................................................................................... 47
3.4.1 Structural Analysis ............................................................................................................. 47
3.4.2 Response Amplitude Operator (RAO) ............................................................................... 49
3.5 Extreme Values .......................................................................................................................... 53
3.5.1 General ............................................................................................................................... 53
3.5.2 Short-Term Extreme Approach .......................................................................................... 54
3.5.3 Long-Term Extreme Approach .......................................................................................... 58
3.5.4 Prediction of Most Probable Maximum Extreme for Non-Gaussian Process .................... 61
3.6 Concluding Remarks ................................................................................................................. 65
3.7 References ................................................................................................................................. 66
3.8 Appendix A Elastic Vibrations of Beams ................................................................................. 68
3.8.1 Vibration of A Springhiass System .................................................................................. 68
3.8.2 Elastic Vibration of Beams ................................................................................................ 69
CHAPTER 4 SCANTLING OF SHIP'S HULLS BY RULES ....................................................... 71
4.1 General ....................................................................................................................................... 71
4.2 Basic Concepts of Stability and Strength of Ships .................................................................... 71
4.2.1 Stability .............................................................................................................................. 71
4.2.2 Strength .............................................................................................................................. 73
4.2.3 Corrosion Allowance ......................................................................................................... 75
4.3 Initial Scantling Criteria for Longitudinal Strength ................................................................... 76
4.3.1 Introduction ........................................................................................................................ 76
4.3.2 Hull Girder Strength ........................................................................................................... 77
4.4 Initial Scantling Criteria for Transverse Strength ...................................................................... 79
4.4.1 Introduction ........................................................................................................................ 79
4.4.2 Transverse Strength ............................................................................................................ 79
4.5 Initial Scantling Criteria for Local Strength .............................................................................. 79
4.5.1 Local Bending of Beams .................................................................................................... 79
4.5.2 Local Bending Strength of Plates ....................................................................................... 82
4.5.3 Structure Design of Bulkheads, Decks, and Bottom .......................................................... 83
4.5.4 Buckling of Platings ........................................................................................................... 83
4.5.5 Buckling of Profiles ........................................................................................................... 85
4.6 References ................................................................................................................................. 87
CHAPTER 5 SHIP HULL SCANTLING DESIGN BY ANALYSIS ............................................ 89
5.1 General ....................................................................................................................................... 89
5.2 Design Loads ............................................................................................................................. 89
5.3 Strength Analysis using Finite Element Methods ...................................................................... 91
5.3.1 Modeling ............................................................................................................................ 91
5.3.2 Boundary Conditions ......................................................................................................... 93
5.3.3 Type of Elements ............................................................................................................... 94
5.3.4 Post-Processing .................................................................................................................. 94
5.4 Fatigue Damage Evaluation ....................................................................................................... 95