超大型浮体水弹性响应解析研究

摘要 20 世纪下半叶以来，陆上资源的逐渐匮乏与能源需求量的日益扩大，人们越来越多地将目光投向资源丰富的海洋。海洋中蕴藏着大量的油气与矿物资源，而如何勘探与开采这些资源也一直是科学研究的热点。超大型浮体，是高效开发海洋资源，巩固主权的重要战略装备，因此，有必要加强对超大型海上浮体的研究与开发。

超大型浮体因为其纵向尺寸与垂向尺寸的比值很大，是非常明显的柔性结构。与传统上近似为刚体的海上结构物相比，在研究其水动力特性时，由于其显著的柔性特征，在考虑刚体运动的同时，也应考虑流场改变后引起浮体的弹性变形。这是异常复杂的流固耦合问题，因此需要在二维势流理论的基础上引入水弹性理论来解决。

本文进行了超大型浮体水弹性响应的解析研究，将流场沿浮体长度方向划分成三个子域，速度势分为对称势和反对称势两个部分，利用特征函数展开法求解不同子域的入射势、绕射势和辐射势。将水动力系数、波浪激励力和位移的模态展开式代入到模型中，获得结构与流场的耦合运动方程，通过求解结构运动方程得到各阶模态振型幅值，代回到位移表达式计算结构的水弹性响应。本文还比较了浮体的长度、刚度等模块参数与水深、波长等波浪参数对超大型浮体水弹性响应的影响。77830

毕业论文关键词：超大型浮体；势流理论；水弹性理论；特征函数展开法

Abstract Since the later part of the twentieth century, more and more people are looking to the ocean because of the onshore resource starvation and the growing needs of power source。 Ocean contains rich mineral sources and oil sources, and the exploration or exploitation of these resources is always a hotspot of research。 Very large floating structures(VLFS) are strategic equipments with great significance which can exploit offshore resources effectively and consolidate the sovereign。 Therefore, we have to enhance the research and design of VLFS。

The ratio of longitudinal dimension and vertical dimension is big, which makes VLFS obviously flexible structures。 Compared to traditional offshore structures that are considered as rigid body, because of the large flexibility of VLFS, we should pay attention to their rigid motion as well as the elastic deformation caused by the changes in fluid field when dealing with the hydrodynamic problems。 Structure-fluid interaction problem is very complicated, so we apply the theory of hydroelasticity based on the two-dimensional potential theory to solve it。

In this paper, the analytical study on the hydroelastic responses of the VLFS is carried out, flow field along the floating body in the length direction is pided into three subdomains, velocity potential is pided into symmetric or antisymmetric parts and eigenfunction expansion-matching method is used to solve incident potential, diffraction potential and radiation potential in different subdomains。 By inserting hydrodynamic coefficients, wave exciting force and modal expansion of displacement into the model, the coupled motion equation for structure and flow field is obtained to solve the amplitude of each modal。 which can be inserted back into the motion equation to solve the hydroelastic responses of the structure。 The impact of changes on module parameters and wave parameters such as length or stiffness of the body, depth of water, length of wave is also studied in this paper。

Keywords: very large floating structures; potential theory; hydroelasticity theory; eigenfunction expansion-matching method

第一章绪论 1

1。1 超大型浮体的研究背景 1 超大型浮体水弹性响应解析研究:http://www.youerw.com/jixie/lunwen_89496.html