自升式海洋平台结构的冰振机理及动力失效模式研究

Jack-up offshore platform belongs to the compliant ice-resistant structure, which has cylindrical leg with gear teeth, the failure mode of the ice sheet could be more complicated between ice and jack-up legs. Presently, the use of the development of the abundant resources in arctic region urges the increase of the requirements for jack-up offshore platforms. Many key problems in the ice-resistant design are still unrevealed. So this project is just concerning on the ice-vibration mechanism and structural dynamic failure modes for the jack-up platforms. The studies will be performed through the model tests of the interaction between the ice and the leg with gear teeth in the low temperature laboratory. The failure mechanism of ice sheet and structural response characteristics are determined under different ice velocities and action angle between the ice motion and gear teeth. The measurement method of the total ice force for the complicated structure is established on the new ice-resistant platform in Bohai Sea, and then the formula of the ice loads for the jack-up platform with gear teeth. Based on ANSYS numerical simulation, considering the representative jack-up offshore platforms, structural dynamic failure modes and criteria are analyzed. This project will provide solid theory foundation for ice-resistant design and construction of the jack-up platforms in the polar and sub-polar regions.

自升式海洋平台属柔性抗冰结构，其桩腿在水线位置是两侧带有齿条的圆柱，海冰作用在这类结构上发生的破坏模式非常复杂。随着近年极地海洋资源开发逐渐升温，自升式海洋平台将大规模在冰区使用，但其在设计中仍有许多关键性问题尚未得到解决。为此，本申请项目针对自升式海洋平台结构的冰振机理及动力失效模式问题，通过低温实验室开展冰与带齿条桩腿相互作用的模型实验，明确不同冰速、齿条角度下冰排的破坏形式及结构响应特点；利用渤海新建平台，建立柔性结构总冰力现场测量方法，进而确定适合带齿条圆柱结构的冰力模型；基于ANSYS有限元数值模拟，选取典型的自升式平台结构，确定冰振下该类结构的动力失效模式及判据。本申请项目通过对自升式海洋平台的海冰作用机理研究，确定冰激结构振动的动力失效模式，为极区与亚极区自升式海洋平台的设计、建造提供坚实的理论基础。