组合式超大型浮体结构外荷载作用下水弹性响应研究

发布时间：2018-04-23 14:16

本文选题：水弹性响应 + 组合超大型浮体结构　；参考：《石家庄铁道大学》2014年硕士论文

【摘要】：为了构建稳固可靠的超大型海洋操作平台，深入研究浮体结构的水动力响应问题就显得尤为重要。由于箱型超大型浮体结构水平尺寸远大于其高度尺寸，是典型的扁平结构，这样浮体结构的竖向刚度相对较小，就有必要考虑其弹性变形。由于尺寸巨大及实验各个方面的限制，使得试验研究的难度很大，所以理论研究超大型浮体结构的水弹性响应特性具有实际意义。由于浮体尺寸很大，为了运输、安全等各个方面的方便快捷，都要求浮体设计实现模块化，并通过一定的连接方式(本文以具有不同扭转刚度的铰连接来模拟)就能快速完成组装。为了满足实际工程设计的需要，连接设计的合理性需要满足水动力响应最基本的要求。同时浮体结构在实际工程中会受到浮体上外载荷的影响，所以在超大型浮体结构的设计和建造过程中，研究浮体结构在外载荷作用下的动响应问题具有十分重要的意义。文中以通过铰连接的两个箱式浮体结构物组合模型为例，研究了组合超大型浮体结构在不同周期外荷载作用下各项参数以及其连接刚度对其水弹性响应的影响规律。本文具体研究工作如下：首先根据相应的理论知识，建立了简化的组合超大型浮体结构的简化计算模型。同时根据线弹性理论及Mindlin厚板动力学理论，建立了组合式超大型浮体结构的控制方程和混合边界条件，，并对有关的物理量和相应的表达式进行无量纲化。采用Wiener-Hopf方法，傅里叶变换，刘维尔定理，留数定理等理论，推导出关于中间广义函数的无穷代数方程组。最终通过求解无穷代数方程组，进一步得到在外荷载作用下浮板内动挠度和动弯矩幅值的分布。其次，可根据参考文献[51]对浮板的铰连接刚度的值以及其他参数进行取值，验证以组合超大型浮体结构为研究对象所得到的理论结果的可靠性和正确性，从而直接证明本文方法的正确性。同时，通过选取不同模态数来验证本方法求解结果的收敛性，间接证明本文方法的可行性和可靠性。再次，针对不同周期荷载作用，研究了在铰连接位置固定的前提下，铰扭转刚度对组合超大型浮体结构的水弹性响应的影响规律。另外研究了在铰扭转刚度不变情况下，铰连接位置对组合式浮体结构动响应的影响规律。最后，从减振方面考虑，通过对载荷作用的模块各参数及连接刚度进行优化分析，得到合理的模块参数和铰扭转刚度，以达到最大程度降低其对无外载荷作用浮体模块的动响应幅值。
[Abstract]:It is very important to study the hydrodynamic response of floating structure in order to construct a stable and reliable super large ocean operating platform. Because the horizontal dimension of the box-type super-large floating body structure is much larger than its height dimension, it is a typical flat structure, so the vertical stiffness of the floating body structure is relatively small, so it is necessary to consider its elastic deformation. Because of the large size and the limitation of the experiment, it is very difficult to study the hydroelastic response of the super-large floating body structure theoretically, so it is of practical significance to study the hydroelastic response characteristics of the super-large floating body structure. Because the size of floating body is very large, in order to transport, safety and other aspects of convenience, all require floating body design to achieve modularization, The assembly can be accomplished quickly by a certain connection (this paper simulates the hinge connection with different torsional stiffness). In order to meet the needs of practical engineering design, the rationality of connection design needs to meet the most basic requirements of hydrodynamic response. At the same time, the floating structure will be affected by the external load on the floating body in the actual engineering, so it is very important to study the dynamic response of the floating structure under the external load during the design and construction of the super-large floating structure. Taking the combined model of two box-type floating body structures connected by hinges as an example, this paper studies the influence of the parameters and the connection stiffness on the hydroelastic response of the composite super-large floating structure under different external loads. The specific research work of this paper is as follows: Based on the corresponding theoretical knowledge, a simplified computational model of the composite superlarge floating body structure is established. At the same time, according to the linear elasticity theory and the Mindlin thick plate dynamics theory, the governing equations and mixed boundary conditions of the composite superlarge floating body structure are established, and the related physical quantities and the corresponding expressions are dimensionless. By using Wiener-Hopf method, Fourier transform, Liouville theorem and residue theorem, the infinite algebraic equations for intermediate generalized functions are derived. Finally, by solving the infinite algebraic equations, the distribution of the dynamic deflection and the amplitude of the dynamic bending moment of the floating plate under external load is obtained. Secondly, according to reference [51], the value of hinge connection stiffness and other parameters of floating-plate can be obtained to verify the reliability and correctness of the theoretical results obtained by taking the composite super-large floating structure as the object of study. Thus the correctness of this method is proved directly. At the same time, the convergence of the solution results is verified by selecting different modal numbers, which indirectly proves the feasibility and reliability of the proposed method. Thirdly, the effect of hinge torsional stiffness on the hydroelastic response of composite super-large floating structure is studied under the condition of fixed hinged joint position for different periodic loads. In addition, the influence of hinge connection position on the dynamic response of composite floating structure is studied under the condition that the hinge torsional stiffness is invariable. Finally, considering from the aspect of vibration absorption, the reasonable parameters of the module and the torsional stiffness of the hinge are obtained by optimizing the parameters of the module and the connection stiffness of the load. In order to reduce the amplitude of dynamic response to the floating module without external load to the maximum extent.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P751;P731.2

【参考文献】