Strength and buckling analysis of local ship structure using the IGA method

• Main Authors: Tsou, Wen-Huai, 鄒文懷
• Other Authors: Guan, Pai-Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/93780897200184968586

碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 104 === General ship design requires wide range of analyses from the loading type, efficiency, and resistance to structural strength for torsion, bending and shear. The ship geometry is usually optimized based on the surrounding fluid field to generate the shape with least resistance. Therefore, the Non-uniform rational basis functions (NURBS) are usually employed for the construction of smooth ship hull surface instead of using traditional mesh-based shape approximation [11-13]. Also the isogeometric analysis (IGA) can obtain the numerical model easier and faster than the traditional FEM in ship structural analysis. In analysis process of mesh-based methods, we use different shape functions to build model and approximate the physical field. After we imported the model into analysis program, we need to regenerate the mesh according to the requirement of the shape function. The mesh-generation procedure usually consumes about 80% of the total analysis time [1]. The IGA directly uses B-spline as the shape function, so it can skip mesh generation. Because B-spline is a high order and high continuity function, it can build exact high order surface and analyze contact problems which need more differential time. In this research, we use the advantage of the IGA to build a complete analyzing procedure for the ship structural analysis. We also build the analysis program according to the analysis procedure. After the model is imported into the program, it can generate the mesh and finish the analysis automatically. According to the procedure of building the numerical model, the program could connect the degree of freedom of the structural element (shell element and beam element) without any specifically connecting method. After we complete the verification of the developed program with several benchmark problems, we apply this program to analyze the local ship structure according to the structural design rule. In addition to the whole ship structural analysis, this program is also suitable for ship collision problem or coupling with the meshfree method for ship breaking problem in the future.