| Summary: | 碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 101 === The advantages of composite laminates that had been used in the structure of ship hull widely is high strength, anti-corrosion and light weight. The ability of Anti-shock of ship hull made by composite laminates attacked by underwater explosions is very important. In the past years, the dynamic response of structures had studied through the experiment of underwater explosion. It’s not only expensive but also time-consuming. In this paper, we establish a correct and effective numerical simulation to know the ability of anti-explosion of ship hull structures; we discuss the properties and failure situation in two different ship hull structures subjected to underwater explosion. First of all, we study the theory of composite materials and the basic phenomenon of underwater explosion. Next, we use the analytical solution of composite laminates under uniform load to confirm the mesh size and the reliability of the numerical result. In addition, we do the benchmark study in the analysis of failure to make sure the accuracy of finite element model. Finally, we analyze the damage capability of two different structures of ship hull which are 80 layers composite laminates and composite laminates with hat-shaped stiffener. And we analyze the ability of the anti-shock of ship made by composite material in the same explosion charge, standoff distance but in different incident angle. In the result, mesh size is smaller than 10cm*10cm which can be an accurate solution under the analysis of ship hull. After underwater explosion, composite laminates with hat-shaped stiffener must notice the strength of stiffener; 80 layers composite laminates still have a lot of fibers to support the strength of structure before completely destroyed. In the condition of same explosion charge, standoff distance but in different incident angle. As the result, with incident angle increases, there is no significant difference was found in the peak acceleration of bottom plate. But the root mean square value of vertical acceleration of bottom plate is increased with incident angle becomes larger. Both of the peak and root mean square value of the vertical acceleration of main deck are decreased with incident angle increasing.
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