非线性规划法计算船舶稳性

船舶自由纵倾状态下的稳性曲线计算，最后归结为使消耗在倾斜船舶的功为最小，满足等排水体积约束条件的优化问题。运用非线性规划法中的惩罚函数法作为优化计算方法，与通常采用的拉格朗日乘子法相比，公式推导简洁，而立每一次迭代计算只需计算水线面以下的排水体积及浮心坐标，不需要计算水线面上的面积、漂心、惯性矩等诸要素，减少了计算量，反映了问题的本质。通过对60000吨油船在各种载况下稳性曲线的计算，证明了该方法可行实用。

Application of Nonlinear Programming to Calculation of Ship Stability Curve

The calculation of complete stability curve of an intact ship inclining freely in space can be formed into an optimization problem with an object function that the work consumed on the inclining ship is minimum with the constraint of volume remaining constant. The optimization method presently used is Lagrange Method, which converts the optimization problem with constraint into a nonlinear system of equations that is solved by means of Newton Method with a linear system of equations. This paper presents a new optimization method that is SUMT belonging to Nonlinear Programming. Compared with the traditional method (Lagrange Method), only displacement and center of buoyancy need computing while those elements about waterline plane and Jacobi matrix are not required, which not only decreases computing account but also the formula form is simpler and illustrates the essence of initial problem. The calculation results about an oil tanker of 60000 tons show that the approach given here is practicable and flexible.