超大型浮体多模块柔性连接结构响应研究

发布时间：2018-01-01 18:19

本文关键词：超大型浮体多模块柔性连接结构响应研究　出处：《中国舰船研究院》2014年硕士论文　论文类型：学位论文

【摘要】：超大型浮体尺度和排水量巨大，为了减小结构纵向载荷，要求将它分成若干个模块，各模块之间采用柔性连接器相连，并且允许模块间的某些相对运动。连接器受力形式复杂、载荷较大，弹性变形较大，是整个系统中的一个薄弱环节。连接器的结构型式、连接方式、动力特性、失效模式和强度评估等都是连接器设计的关键问题。本文主要围绕柔性连接器、连接器动力特性和疲劳评估展开研究工作，主要内容如下： 1.首先介绍了超大型浮体的基本概念、模块连接方式和各种柔性连接器，讨论了柔性连接器的设计原则，，分析了一种新型球状连接器的结构型式和连接过程。 2.然后基于多浮体运动理论，包括结构动力学理论和三维势流理论，采用RMFC模型理论给出了连接器载荷的表达式和浮体的频域运动方程。以三个不同计算模型为例，通过Sesam/Wadam计算水动力，分析了连接器刚度、浪向角、海况以及模块数量对浮体运动响应和连接器载荷的影响。对三个模型的设计参数和计算结果做了比较，分析了浅水效应，研究了浅吃水超大型浮体连接器的动力特性。 3.最后通过Patran/Nastran计算了连接器在不同浪向角和频率下的应力，分析提取出了危险节点的应力传递函数。然后分别采用S-N曲线法和断裂力学法对连接器进行疲劳分析，并对两种方法做了比较分析。在S-N曲线法中，选取了7条不同S-N曲线进行疲劳寿命评估，分析了浪向角、短期海况对疲劳损伤的贡献率。在断裂力学法中，选取了30组不同尺寸及形状的初始裂纹，分别采用Paris公式单直线形式和双直线形式对连接器进行了疲劳寿命评估，研究了初始裂纹对疲劳寿命和裂纹扩展的影响。
[Abstract]:In order to reduce the longitudinal load of the structure, it is required to divide it into several modules, each of which is connected by flexible connectors. The connector is a weak link in the whole system, which is a weak link in the whole system. The structure type, connection mode and dynamic characteristics of the connector are also allowed. Failure mode and strength evaluation are the key problems in connector design. This paper focuses on flexible connectors, dynamic characteristics of connectors and fatigue assessment. The main contents are as follows: 1. The basic concept of super large floating body, the mode of module connection and various flexible connectors are introduced, and the design principles of flexible connectors are discussed. The structure and connection process of a new type spherical connector are analyzed. 2. Then based on the theory of multi-floating body motion, including the theory of structural dynamics and three-dimensional potential flow theory. The expression of connector load and the motion equation of floating body in frequency domain are given by using RMFC model theory. Taking three different calculation models as examples, the hydrodynamic force is calculated by Sesam/Wadam. The effects of connector stiffness, wave angle, sea condition and the number of modules on the response of floating body and the load of connector are analyzed. The design parameters and calculation results of the three models are compared, and the shallow water effect is analyzed. The dynamic characteristics of super large floating connector with shallow draught are studied. 3. Finally, the stress of the connector at different wave angles and frequencies is calculated by Patran/Nastran. The S-N curve method and fracture mechanics method are used to analyze the fatigue of connectors, and the two methods are compared and analyzed. Seven S-N curves were selected to evaluate the fatigue life, and the contribution of wave angles and short-term sea conditions to fatigue damage was analyzed. In the fracture mechanics method, 30 groups of initial cracks with different sizes and shapes were selected. The fatigue life of connectors was evaluated by Paris formula single line form and double straight line form respectively. The effect of initial crack on fatigue life and crack propagation was studied.
【学位授予单位】：中国舰船研究院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P751

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