| With increasing efforts to explore ocean resources and the setting forth of national marine strategy, it is of significant importance to enhance the capability of marine law enforcement. In recent years, there were frequent disputes in China’s surrounding seas over islands sovereignty, maritime demarcation, ocean exploitation, commercial fishing and so on. These dispute cases tend to appear in the form of tracking, interference and striking between the ships of two sides. As such, improving the crashworthiness of marine surveillance ship is not only of great importance to guaranteeing the safety of law-enforcement personnel, but also of great strategic significance to seize control in those disputes. Therefore, it’s necessary to assess the crashworthiness of surveillance ships and propose corresponding improved scheme. In this thesis, a kind of novel crashworthy ship side structure designed for 1000-ton and 1500-ton surveillance ships is verified by both experimental and numerical methods.The main work of this thesis can be summarized as follows:Firstly, the experiment scheme of ship side structure model test is described in detail, including the design philosophy, model configuration, specimen manufacturing, experiment setup and so on. And then the crashworthiness of different models are compared in terms of force-indentation behavior, energy absorption capability and deformation mode.Secondly, some key technical issues, such as nonlinear material behavior, failure criteria and mesh sensitivity are discussed based on a set of published indentation tests. The verified methods are then applied to simulate the novel crashworthy structure model tests described in this thesis.Finally, the crashworthiness of 1000-ton and 1500-ton marine surveillance ship is preliminarily assessed by explicit analysis code LS-DYNA. The energy absorption capability of corresponding ship side structure optimization plans is also assessed and compared with the original structure design. |
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