Shock Response of Composite Ship Hull Subjected to Underwater Explosion

• Main Authors: Jun-Xiong Ruan, 阮俊雄
• Other Authors: 洪振發
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/86054116097655308881

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 102 === The composite material structure has the advantage of high tensile strength, anti-corrosion and light weight, but has poor shear and compression strength. In recent years, the properties of composite materials, such as fire and shear resistance, have been improved, the potential of application on commercial and naval vessel are promoted substantially. Consequently, the issue of shock response of composite hull of navy vessels subjected to underwater explosion (UNDEX) becomes more and more important. In the past decade, most of the research work of UNDEX acquired by experiments, and this way is very expensive and time consuming. In this paper the Finite Element (FE) was applied to investigate the dynamic responses of the composite materials ship hull subjected to UNDEX. First of all, the comparison study by shock load on structure by estimation of three methods were curried out, which are the Arbitrary Lagrange Euler (ALE) with 3D FE model for water domain, USA and Subsea Structural Analysis (LOAD_SSA) method. Further, the impact responses of composite plate panel with aforementioned three different methods were examined. In the result, ALE method needs whole FE model for fluid domain, USA method requires a fluid-structure interface of wetted surface, the analysis results of these two methods agree very well, On the other hand, the impact responses by LOAD_SSA method are about 25% large, but the overall trend is still consensus with the other two if the fracture of structure component does not appear. It need only very small computer time compared with the other two methods and can be used for qualitative study for underwater explosion (UNDEX). For the damage analysis of composite materials, the USA is proposed. Last but not least, the dynamic responses of a composite materials ship hull subjected to UNDEX were investigated. Several comparison studies were conducted, first, the same amount of charge, same detonation distance but different angle of incidence. And then, the conditions with the same amount of charge, same keel shock factor (KSF), different angle of incidence and different types of ships were performed. As the result revealed, the maximum impact acceleration is increasing as the angle of explosion increases under the same distance. The maximum acceleration of gunwale and the deck center is less relevant with the distance of explosion with the same KSF. And the maximum acceleration of the bottom center of ships is quite familiar with the acceleration–time chart under different types of ships.