The Study of the Failure Behavir of Ship Structure on Collision and Grounding.

当油轮在风浪汹涌的海面上发生碰撞或搁浅时，货油泄漏会对环境造成严重的破坏，近年来引起了世界各国的高度重视。本研究旨在探讨在发生油轮事故时，降低溢油可能性的油船结构，并对油船结构的规范提出新的标准。第一年，基于刚体-塑性铰理论，研究了船头结构在碰撞情况下的破坏行为。通过与试验数据的对比，研究了焊缝尺寸、动态效应和速度相关性的影响。实验和分析结果吻合较好。弓结构分为几个较简单的部分，即L式、T型和+型结构。对每种结构的吸能能力进行了分析，并与有限元分析进行了比较。通过将结构分成几个简单的结构，将简单结构的分析扩展到更复杂的结构。研究了船首结构倾角对破碎力的影响，考虑了破碎力的计算方法，提出了可供早期设计使用的简化计算公式，并研究了该船与其他船舶相撞时舷侧结构的破坏行为。利用刚体-塑性铰理论，通过有限元分析，并与试验数据进行比较，推导出简化方法的方程。最后对油船双壳结构和中层结构进行了风险分析。

When the collision or grounding of tanker occur in the stormy sea, the spill of cargo oil can cause serious damage to the environment and called much attention worldwide recently. This study investigate the tanker structure that will reduce the possibility of oil spill when the tanker accidents occurs, and propose new standard for the regulations on tanker structure.First step is the clarification of the failure behavior. In the first year the crushing behavior of the bow structure in the case of collision was investigated based on the rigid body-plasticity hinge theory. The comparison with the experimental data is carried out to investigate the effect of the size of the welds and the dynamic effect and the speed dependency. A good agreement was observed for the experiments and analysis. The bow structure was divided into several simpler parts, namely L type, T type, and + type structure. The analysis of the energy absorption capability for each type of structure is made, and the comparison with the finite element analysis is made. This analysis for simple structure was extended to more complex structure by dividing the structure into several simple structures. The effect of the inclination of the bow structure was also investigated, and the method of deriving the crushing force for such structure is also considered, and simplified equations that can be used in early design stage are proposed.Also the failure behavior of the side structure that will occur when the ship is struck by other ship is investigated. The finite element analysis and comparison with experimental data is carried out to derive the equation of simplified method by rigid body-plastic hinge theory. Finally the risk analysis of double hull structure and middeck structure of tanker is made.