船舶雙層殼結構抗撞能力估算法研究

The Approximate Method to Predicate the Crashworthiness of Ship Double Hull Structures

船體雙層殼結構主要以垂直相交的鋼板構成，為船殼重要的結構型態。本文先以有限元素法分析雙層殼結構遭受圓錐形剛體撞擊過程的破壞狀態，以瞭解雙層殼結構各種結構件的破壞機制。針對其破壞現象歸納成：平板拉伸、平板穿透、平板剪切與撕裂、以及深樑凹陷與褶皺等4種基本破壞模式。依據此4種模式之破壞現象推導其破壞消能與抗撞阻力估算式。船體雙層殼結構遭受撞擊所造成的破壞歷程，可視為不同階段基本破壞模式之組合，而以基本破壞模式分段估算，以推算雙層殼結構遭受撞擊後之整體消能與抗撞阻力。最後以本文推導之估算式與有限元素法分Wang[1]之雙層殼結構撞擊破壞試驗模型，並與該文之試驗比較，結果顯示三者之抗撞阻力對撞擊深度分佈頗為一致。 In this paper the finite element method was used to analyze the damage states of double hull structures struck by a rigid conical body to understand the failure mechanism of each structural component. The damages of double hull structures were classified into four fundamental damage modes, which are the stretching mode, the tearing mode and the penetration mode of plates, as well as the denting mode for single girder and crossing girders. The simplified formulae for approximation of energy dissipation and impact resistance of four fundamental damage modes were derived. The overall energy dissipation and impact resistance of a stuck double-hull structures can be estimated by assembly of these fundamental failure mechanisms. Finally, the experimental models of double-hull structure from Wang (2000) were selected as case studies. The damage states of double-hull structures were analyzed by FEM. The impact resistance of the struck structure was also calculated by approximated method. The results obtained from experiment, FE-analysis and the approximate methods have good agreements.