波激振动和砰击颤振对大型油船疲劳强度影响研究

文章给出线性波激振动和砰击颤振引起的大型油船结构疲劳贡献度的计算方法。基于三维线性水弹性理论可计算得到包括刚体和2节点的振动模态下的垂向弯矩的传递函数，采用谱分析法对某30万吨油船进行结构疲劳强度计算，分析波激振动对船体结构疲劳损伤影响；基于二维非线性波浪载荷程序（含砰击颤振的波浪载荷），采用时域方法对该油船进行船体梁弯矩计算，分析砰击颤振对船体梁弯矩及疲劳载荷的影响；结果表明对于该类大型油船波激振动和砰击颤振对船体的结构疲劳损伤的影响不可忽略。

Springing and whipping impact on fatigue strength of very large oil tankers

This paper presents the calculation method of the springing and whipping induced structural fatigue contribution to very large oil tankers. The vertical bending moment RAOs including rigid body motions and two-node vibration are calculated by the linear three-dimensional hydroelasticity theory. The structural fatigue strength of a 300 000 ton oil tanker is calculated by the spectral method for the analysis of the springing effect on the fatigue damage of hull structures. The vertical bending moment in time domain is calculated by the two-dimension nonlinear wave load program with consideration of the whipping induced wave loads, resulting in the evaluation of the whipping effect on the hull girder bending moment and on the fatigue load. The results show that the wave induced springing and whipping have a strong impact on the structural fatigue damage of the very large oil tankers.