波激振动的理论预报及与实船试验结果的比较

本文研究一艘大型海船的波激振动问题。该船在运行过程中发生了频繁的波激振动，导致严重的结构裂纹。文中对四种预报船体波激振动响应的理论及其计算机程序进行了描述。这些理论在计算水动力载荷和结构振动时具有各自的特点，如：线性、二阶、非线性、频域、时域、二维和三维等。相应的程序(WASIM，SOST，SINO和VERES)对低频波浪诱导响应预报已有较多的验证。文中对各程序在波激振动预报中的前提条件作了说明。计算中进行了参数敏感性分析并给出了主要结果。在与实船试验结果的比较过程中选择了十个不同的工况，对其海况、航向和试验现象给出了简要描述。对低频波浪诱导和高频波激振动响应分别进行了比较，得出了一些有意义的结论。

Theoretical Predictions of Springing and Their Comparison with Full Scale Measurements

The present paper considers a large ocean going ship with significant springing responses,which have made a large contribution to the fatigue cracking for certain structural details. Four different theories for predicting ship responses and associated computer programs for predictions of springing are described.These theories represent four different approaches with various characteristics,e.g.linear, second-order,nonlinear,frequency-domain,time-domain,two-dimensional and threedimensional,in calculating hydrodynamic loads and vibrations.The numerical programs,WASIM (DNV),SOST(DTU),SINO(CSSRC) and VERES(Marintek), have been well validated for ordinary ship responses. Assumptions regarding how the different programs are used in the present calculations are provided.Sensitivity studies are carried out and the main results are presented. A selected number of full-scale measurements with various sea states and headings used for comparison between numerical results and the measurements are described.The comparison between simulated and measured high frequency (2-node vibration,denoted HF) and low frequency (wave-induced,denoted LF) stress es in addition to some important observations are made.