Study on Stability Standards of ship

综述了国内外船舶横浪稳性标准的研究现状。对船舶在后向横浪中直至倾覆的临界状态进行了稳性标准研究。本文对在严重四分波中拖曳的船模的侧向力和横摇力矩进行了分析和试验研究。为了研究船舶在极低遭遇频率下的垂荡和纵摇运动的侧力，进行了大量的模型试验。将侧向力分为佛汝德-克雷洛夫力、绕射力和升力，并进行了详细的讨论。考虑到船舶沉没截面积的变化，研究了垂荡和纵摇运动对船舶侧向力的影响，并将实验测得的模型侧向力与理论预测值进行了比较。利用数值模拟程序，指出了船舶在大纵浪和大横浪中倾覆的临界状态。讨论了几个参数对临界情况的影响，以调查倾覆的可能原因。此外，为了简化仿真程序，在实用公式中还考虑了大位移时作用在船体上的Froude-Krylov力。

Stability standards of domestic and international regulation are reviewed for ships in beam sea condition. Critical situations leasing up to capsizing of a ship in following quartering seas an investigated for stability standard. An analytical and experimental study of the side force and yaw moment on a ship model towed in severe quartering waves has been conducted. In order to investigate the side force on the ship with heave and pitch motions in a very low encounter frequency, extensive model tests have been carried out. The side force is divided into Froude-Krylov force, diffraction force and lift, and discussed in detail. The effects of heave and pitch motions to side force on the ship are investigated by taking into account the change of submerged sectional area Comparisons of the experimentally determined force on the model and a theoretical prediction are presented. Critical situations le ading up to capsize are pointed out for a ship in severe following and quartering seas by using the aid of numerical simulation program. The effect of several parameters on the critical situation is discussed to investigate the possible causes of capsizing. In addition, Froude-Krylov forces acting on a ship with large amplitude displacement are evaluated in the practical formulas to make simulation program simple.