海事事件中的航行事故以船舶之間的碰撞為數最多。為了降低船舶在碰撞過程造成的結構破壞，本文旨在探討鋁合金雙體船與較小噸位鋼船發生碰撞時之損傷範圍及破壞模式。首先透過計算流力方法分析撞擊瞬間雙體船的附加質量與阻尼係數，並將其配置於船體結構上以模擬運動響應。接著以顯式動態有限元素方法分析已針對碰撞區域細化元素的雙體船左舷結構，鋁合金材料的設定則是包含了彈性、塑性和破壞力學模型。碰撞條件假定雙體船舯處側邊遭到鋼船以不同船速撞擊。在撞擊過程中觀察船體結構其外板、橫向艙壁、縱向與橫向大肋骨等構件的變形與破壞現象。透過不同船速的撞擊，分析凹陷深度與損傷範圍，發現動能主要轉換為摩擦損失和內能，而內能中主要由塑性變形吸收。

Navigational casualties including collisions represent the most of the marine casualties and incidents. In order to reduce the structural damage caused by collision, this article investigates the crashworthiness of an aluminum catamaran when colliding with a smaller steel boat. First, the added mass and damping coefficient of the catamaran were computed by CFD and deployed on the structural model for motion response. Next, an explicit dynamic finite element analysis of the port structure with refined elements around the collision area was carried out. The aluminum material included elastic, plastic and failure mechanics models. The collision conditions assumed that the steel boat hit the side of the catamaran at different speeds. The deformations and damages of the shell plates, transverse bulkheads, longitudinal and transverse web frames and other components were observed during the impact process. The collision penetration and impact resistance were obtained against impact speeds to reveal the kinetic energy converted into frictional loss and internal energy, which was majorly absorbed by plastic deformation.