• 作者： 方銘川; 廖正民
• 作者服務機構： 國立成功大學造船及船舶機械工程研究所
• 中文摘要： 本論文中提出了一以截片理論為基礎的方法來預測船隻在斜向波中所受之非線性負荷。由於過去在流體動力學良好的發展，使得流體動力係數及力量可以預估得相當好，因此在本研究中，作著將船體視為－自由樑，而利用簡樑理論來預估船體之波浪負荷，如彎矩、剪力及扭矩。本文中利用過去發展良好的線性基礎再發展一套分析大波浪中的非線性負荷模式，此外，為了去掉橫移與橫擺之數值漂移現象，分別利用假想恢復力與數位濾波法之技巧來去除此現象。而一系列之分析中得到一些有用的建議，可供作此類分析者參考。因此本文所發展之計算過程，可視為預測船體運動與波浪負荷的有效分析工具之一。
• 英文摘要： In the paper, a prediction method for the nonlinear wave loads of a ship advancing in oblique waveswith infinite water depth is proposed. Because of the good development in the hydrodynamics, thecorresponding hydrodynamic coefficients and forces on ships can be well estimated. With this good basis,the authors consider the ship as a free-free beam and use the simple beam theory to estimate thecorresponding sea loads along the ship hull, i.e., the wave bending moment, shear force and torsion momentat any ship section. Based on the well developed linear theory, an analytical model of the nonlinear waveloads for a ship in large oblique waves is further constructed. Time domain analyses, including the instantgrid generation technique (IGGT), for the corresponding sea loads are performed. Furthermore, to avoidthe numerical drift phenomena in the sway and yaw mode motions, the Artificial Restoring ForceTechnique(ARFT) and Digital Filter Technique(DFT) are applied to solve five coupled equations of motion.A series of analyses is performed in this paper, and some valuable suggestions are also submitted Thecalculation procedures developed here may be considered as an efficient analytical tool for researchersto predict the ship motions and wave induced loads.
• 中文關鍵字： nonlinear wave loads; time domain; digital filter
• 英文關鍵字： --