Research of Springing and Whipping Influence on Ultra-Large Containerships' Fatigue Analysis  

作　　者：REN Huilong ZHANG Kaihong LI Hui 任慧龙;张楷弘;李辉(College of Shipbuilding Engineering, Harbin Engineering University)

机构地区：College of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001, China

出　　处：《Journal of Shanghai Jiaotong university(Science)》2018年第3期429-437,共9页上海交通大学学报（英文版）

摘　　要：Rules of Classification Societies all around the world have made changes on design wave loads' value and fatigue influence factor modification due to the influence of springing and whipping on ultra-large containerships.The paper firstly introduced 3-D linear hydroelastic theory in frequency domain and 3-D nonlinear hydroelastic theory in time domain, considering large amplitude motion nonlinearity and slamming force due to the severe relative motion between ship hull and wave. Then the spectrum analysis method and time domain statistical analysis method were introduced, which can make fatigue analysis under a series of standard steps in frequency and time domain, respectively. Finally, discussions on the influence factor of springing and whipping on fatigue damages of 8500 TEU and 10000 TEU containerships with different loading states were made. The fatigue assessment of different position on the midship section was done on the basis of nominal stress. The fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. Besides, some suggestions on calculating load case selection were made to minimize the quantity of work in frequency and time domain. Thus, tools for fatigue influence factor modification were provided to meet the demand of IACS-UR.Rules of Classification Societies all around the world have made changes on design wave loads＇ value and fatigue influence factor modification due to the influence of springing and whipping on ultra-large containerships. The paper firstly introduced 3-D linear hydroelastic theory in frequency domain and 3-D nonlinear hydroelastic theory in time domain, considering large amplitude motion nonlinearity and slamming force due to the severe relative motion between ship hull and wave. Then the spectrum analysis method and time domain statistical analysis method were introduced, which can make fatigue analysis under a series of standard steps in frequency and time domain, respectively. Finally, discussions on the influence factor of springing and whipping on fatigue damages of 8500TEU and 10000TEU containerships with different loading states were made. The fatigue assessment of different position on the midship section was done on the basis of nominal stress. The fatigue damage due to whipping can be the same as the fatigue damage due to springing and even sometimes can be larger than the springing damage. Besides, some suggestions on calculating load case selection were made to minimize the quantity of work in frequency and time domain. Thus, tools for fatigue influence factor modification were provided to meet the demand of IACS-UR.

关 键 词：SPRINGING WHIPPING fatigue analysis HYDROELASTICITY 

分 类 号：U661[交通运输工程—船舶及航道工程]