船舶結構遭錐狀體撞擊時的撕裂破壞之研究

The Tearing Damage of Ship Structures Subjected to Impact of Wedge-Shaped Body

船舶碰撞與擱淺時造成的結構破壞有多種模式，本文著重在錐狀物體與船體結構撞擊所造成的剪切撕裂形態的破壞狀況。先檢討近20年來文獻上在分析板結構受錐狀體撞擊狀況時，破壞模式的假設與理論的思考方式，以及建議的預估板結構的破壞消能與抗撞阻力的簡算式。其次歸納錐狀體撞擊平板的破壞模式與板塊結構撕裂之力學特性，建立撕裂破壞模式，推導合理的簡化半理論估算方法以推算破壞狀況下的能量消散與切割阻力。並以有限元素模型分析板塊結構受錐狀體撞擊的撕裂破壞狀況，其結果與不同估算方式比較，檢討本文推導簡化估算式的精確性。最後選擇NSWC 4種不同船舶擱淺撞擊模型中之兩種[18]，以有限元素分析，並採用等效板撞擊撕裂模型以不同估算方式推估，比較其結果與確認本文應用之可行性。 There are many failure modes of structures while the grounding and collision of ships occurred. This paper focuses on the tearing damage of ship structures under impact of wedged body which may be a striking ship box or a grounding rock. The developments of the modeling and methods to solve the tearing modes of plate and structural block subjected to impact of wedge-shaped structure in past two decades were reviewed first Then the approximate formulae to predicate the energy dissipation and tearing resistance at given damage status of structures have been derived An example of the tearing damage analysis of plate subjected to impact of wedge shaped body by FEM analysis was performed. The results obtained from FEM analysis and different approximated formulae were compared. The accuracy of the different proposed approximate formulae was reviewed. Finally, two grounding experiment model performed by NSWC [18] were analyzed by FEM and different approximate formulae, the results were compared.