Research On Collision Response And Strength Assessment Method For Submersible

As a vital research field in naval and ocean structure, collision is one of the common accidents during the lifetime of submersible, the result of which is more dangerous than that happened on surface ship because of its smaller reserved buoyancy and deep water pressure. It is important to study the collision problems of pressure structures. The FEM is adopted to study the collision problems of submersible in this paper. The main work is as follows,1) On the basis of discussion of the external and inner mechanics, some improvement suggestions to current methods are given.2) The fundamental theory and key technology for numerical simulation of collision are studied and discussed. The added mass method is adopted as an analysis approach and the added mass coefficient is calculated.3) Benchmark study is performed in this paper, the aim of which is to check the present collision calculating methods and tools as well as to review the veracity of the numerical simulation of the real collision procedure.4) The collision process of submersible is studied through numerical simulation method; the approach of studying collision is obtained. Besides, we discuss the motion lag of the submersibles and consider the impact of some collision parameters and different structure configurations.5) The approach of assessing collision strength is obtained, and the critical collision velocity is put forward as an index.6) Two methods to improve the capability of resistance to collision for the pressure structure are put forward, and the crashworthiness index is inducted.