60万桶FPSO船体在十年一遇海况下的大幅运动模拟

Large amplitude motions simulation of 600 000 barrels of FPSO hull once-in-a-decade sea conditions

简述了船舶在规则波中纵向大幅运动的计算方法,并将该方法推广到不规则波的运动计算中.基于切片理论的扩展方法,考虑由于船体的湿表面变化而产生的非线性因素,采用频域计算方法和时域计算方法相结合,线性处理和非线性修正相补充的方法,对水面船舶在不规则波中的纵向大幅运动进行计算.文中采用的谱分析技术,理论上讲不适用于船舶的大幅运动,但由于大量计算结果表明船舶纵向运动响应非线性不强,这就为我们的计算提供了基本条件,并以FPSO船体为例,运用C++语言编程实现船体在十年一遇海况下的大幅运动模拟,得到船舶运动六自由度的运动响应曲线.

The calculation method of large amplitude vertical motions of ships in regular waves was briefly introduced in this paper.The method was generalized to the calculation of irregular waves.Based on the exteension method of the strip theory and in combination of the nonlinear factors due to the wet surface changes of ships,the frequency domain analysis method and the time domain method were used together with the linear and nonlinear corrected methods to calculate the large amplitude vertival motions of ships in irrgeular waves.The method was simple and practical.It had great engineering significance for ship design.The spectral analysis technology used in this paper did not apply to the large amplitude motions in theory.But a great number of calculating results showed that the nonlinearity of a ship's vertical motion response was not strong,which provided the basic conditions for our calculation.Take FPSO hull,for example,C++ computer language is used to realize large amplitude motion simulation once-in-a-decade sea conditions and to obtain response curves in six degrees of the ships.