基于离散元法的海洋结构冰荷载分析

发布时间：2018-06-06 17:37

本文选题：海冰 + 离散元　；参考：《大连理工大学》2014年硕士论文

【摘要】：近年来,随着海洋油气开发逐渐涉及到寒区领域,冰区海洋工程受到了越来越多的关注。海洋结构在冰区能否安全工作在冰区工程上是首要关心的问题。为了保证冰区海洋结构的安全性,需要对海洋结构冰荷载及其影响因素进行深入研究。海冰与海洋结构相互作用是一个十分复杂的过程。海冰参数如海冰的类型、强度、厚度、速度等及结构参数如结构形状、尺寸、刚度等都会对这一过程产生重要影响。本文首先介绍了海洋结构冰荷载研究的背景及涉及的主要问题,在实验研究、理论分析和数值模拟三个方面对国内外海冰与结构相互作用的研究情况进行了总结。分析了海冰与直立体海洋结构、锥体海洋结构作用时的原理、形式、破坏机理等,对各结构冰力特点进行了说明。在数值模拟方面,对离散元方法进行了简要的介绍。对海冰的物理力学性质进行了研究与总结,分析了海冰密度、温度、盐度和卤水体积等参数对海冰力学性质的影响以及海冰强度参数如压缩强度、弯曲强度及剪切强度对海冰动力过程的作用。在明确海冰物理力学性质的前提下,建立了海冰离散元模型,阐述了海冰离散元的基本原理。给出了海冰离散元的接触模型、粘结模型、断裂模型、水动力模型等海冰力学模型和结构模型如柱体单元、锥体单元和三角形单元。运用海冰离散元模型,对汉堡冰池的锥体实验,Jz20-2MUQ平台抗冰锥与平整冰与相互作用过程,及平整冰与船体相互作用的过程进行了数值模拟。分析讨论了海冰厚度、速度及温度对冰力结果的影响。通过对汉堡实验的模拟,对实验结果与计算结果进行了对比,验证了计算结果的准确性。通过对破冰船的模拟,论证了海冰离散元方法用于复杂海洋结构模拟的可行性。最后,讨论了海冰离散元方法在海冰荷载研究应用中存在的问题。
[Abstract]:In recent years, with the development of offshore oil and gas gradually involved in the field of cold regions, more and more attention has been paid to marine engineering in ice regions. Whether the ocean structure can work safely in the ice area is the primary concern in the ice area engineering. In order to ensure the safety of ocean structure in ice area, it is necessary to study the ice load of ocean structure and its influencing factors. The interaction between sea ice and ocean structure is a very complicated process. Sea ice parameters such as sea ice type, strength, thickness, velocity and structural parameters such as structure shape, size and stiffness will have an important effect on this process. In this paper, the background and main problems of ice load research on marine structures are introduced, and the researches on the interaction between sea ice and structure at home and abroad are summarized in three aspects: experimental research, theoretical analysis and numerical simulation. The principle, form and failure mechanism of sea ice and straight ocean structure and conical ocean structure are analyzed, and the ice force characteristics of each structure are explained. In the aspect of numerical simulation, the discrete element method is briefly introduced. The physical and mechanical properties of sea ice are studied and summarized, and the density and temperature of sea ice are analyzed. The influence of salinity and brine volume on the mechanical properties of sea ice, and the effect of sea ice strength parameters such as compressive strength, bending strength and shear strength on the dynamic process of sea ice. The sea ice discrete element model is established and the basic principle of sea ice discrete element is expounded. The contact model, bond model, fracture model, hydrodynamic model and structural model of sea ice discrete element such as cylinder element, cone element and triangle element are given. The interaction between ice cones and flat ice and the interaction between flat ice and hull were simulated numerically on the Jz20-2MUQ platform of Hamburg ice tank. The effects of sea ice thickness, velocity and temperature on ice force are analyzed and discussed. Through the simulation of the Hamburg experiment, the experimental results are compared with the calculated results, and the accuracy of the calculated results is verified. Based on the simulation of icebreaker, the feasibility of sea ice discrete element method for complex ocean structure simulation is demonstrated. Finally, the problems existing in the application of sea ice discrete element method in the study of sea ice load are discussed.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731.15;P75

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