Stability Analysis And Calculation Of Capsizal Probability Of A Ship In The Rolling Motion

A ship must suffer from wind and wave unavoidably when sailing on sea, and wewonder if their stability is adequate for no capsizal. In other words, we want to knowthe exact numerical value of capsizal probability which is a focus in the ship group. Inthe past, the effect of wind was considered as a static load, but in actual, it is dynamicwind that acts on ships, which leads to diverse angle in the rolling motion as the sameas wave. So, wind is also considered as a dynamic load in this thesis. The stability of ships is studied at three aspects in this thesis: beam wave, beamwind, wave and wind. Harmonious wave equations and multiple scales are applied inpredigesting the process of calculating, in the end an equation is educed whichindicates the connection of the amplitude in the rolling motion and frequencyencountered then every amplitude given frequency encountered can be obtained bythe process in Matlab. The capsizal probability of ships is studied at two aspects in this thesis: whether ornot exiting biased angle in the rolling motion. The numbers showing the seaconditions are mostly from statistics, and wind speeds can be obtained using theconnection of wave high and wind speed.Every amplitude in different status can besolved by the equations educed from studies of stability. Then we can draw the figuresof ships capsizal probability density, accordingly, capsizal probability can becalculated by integral limiting the angle at which water may be come into a ship. Finally, two examples are given calculating the amplitude-frequency equationand stability equation in wave, in wind, in wind and wave, showing in figures. Thenaccording to the method mentioned above, capsizal probability is also calculated.