船体结构直接计算法中垂向波浪弯矩的确定

The Determination of Vertical Wave Bending Moment in Direct Calculation of Method of Ship Structure

根据极值统计学原理，论证了长期特征最大值和长期极值特征值之间的关系，即当弯矩循环次数充分大时，最可能极值即为特征最大值，设计极值即为设计最大值。根据这一结论，提出了一种估算船舶垂向非线性波浪弯矩长期特征最大值的简便方法，使计算大为简化。数值计算表明，上述方法给出的计算结果精度较好。

Based on the principle of extreme value statistics, the relationships between long-term characteristic maximum values and long-term extreme characteristic values are demonstrated. If the number of the wave bending moment cycles is large enough, the most probable extreme value will be the characteristic maximum value , and the design extreme value will be the design maximum value. Bases on this conclustion, a simple method for estimating the long-term characteristic maximum value of vertical nonlinear wave moment is proposd, by which the calculation can be considerably simplified. The numerical results show that the degree of precision of the calculation results obtained by this method is quite satisfactory.