Development of a System to Assess the Damage and the Residual Strength of Pipe and Shell Structures under Collision

海上采油结构物或易燃化学品储罐的碰撞可能造成人员伤亡和污染等社会问题。因此，必须采取安全措施。为了保证结构在可能的碰撞作用下的安全性，需要对结构的损伤和损伤后的剩余强度进行评估，本文通过物理和数值试验对管壳结构在碰撞作用下的性能进行了研究。此外，还试图建立一个绘图系统，通过提供有关结构物在碰撞下的损伤和剩余强度的基本信息来帮助设计人员。例如，对于海洋结构物，结构物类型非常多样化，如导管架、自升式和半潜式。因此，它们的刚度和强度因平台而异。此外，碰撞物体的大小从小的坠落物体到巨大的冰山变化很大。可以预期的是，根据结构的类型和碰撞体的大小的组合，碰撞现象改变其特性。因此，有必要根据合理的参数来描述碰撞问题，以了解涉及广泛变化的碰撞现象的基本特征。本文对碰撞构件和整个结构的碰撞响应进行了一系列的实验和数值研究。在此基础上，提出了表征碰撞现象的几个参数，并利用这些参数对碰撞问题进行了分类。

Collisions involving offshore structures for oil production or tanks used to carry flammable chemical may cause loss of human life and social problems such as pollution. Thus, safety measures are strongly required. To ensure the safety of the structures under possible collision, it is necessary to estimate the damage and the residual strength after the damage.In this research, the behavior of tubular and shell structures under collision are investigated by physical and numerical experiment. Further, construction of a plot-type system to assist designers by supplying fundamental information on the damage and the residual strength of structures under colli ion is attempted.In case of offshore structures, for example, the structural types are quite diverse such as jacket, jack-up and semi-submersible types. Consequently, their stiffness and strength vary from one platform to another. In addition, the size of the colliding body widely varies from small dropped object to huge iceberg. It may be expected that depending on the combination of the type of the structure and the size of the colliding body, the collision phenomenon changes its characteristics. Thus, it is necessary to characterize the collision problem based on rational parameters to understand the fundamental features of collision phenomenon which involves wide variations. Series of experimental and numerical studies on collision responses of the collided member alone and also the whole structure are conducted in this research. Based on these, couple of parameters which characterize the phenomena were proposed and collision problems are classified using these parameters.