【作者】 罗鹰；

【导师】 段宝岩；

【作者基本信息】 西安电子科技大学 ， 机械制造及其自动化， 2004， 博士

【摘要】 本文的研究工作由两部分组成：一是大型星载可展开天线的动力优化设计，二是工程结构的系统优化设计。大型星载可展开天线动力优化的研究工作是总装备部“十五”重点预研项目—大型可展开天线技术的一部分，主要包括以下几个方面： 1．论述了当前大型星载可展开天线的研究现状，提出了我国在可展开天线设计，特别是在可展开天线动力优化设计方面存在的问题，说明了开展星载可展开天线动力优化研究的必要性与艰巨性。 2．根据星载天线反射面结构形式、天线展开驱动类型的不同，分别对星载可展开天线结构进行了归纳总结，并就星载可展开天线所用材料进行了有针对性的介绍，对星载天线未来的发展趋势进行了展望。 3．通过对索网结构几何非线性的分析研究，建立了周边桁架式可展开天线结构的非线性静力分析与动力分析计算模型，并将其应用于实际天线结构的计算中，取得了合理的计算结果。 4．对周边桁架式可展开天线结构动、静力性能以及各种设计参数对其性能的影响进行了系统地分析，建立了周边桁架式可展开天线结构处于展开状态时的动力优化模型，该模型以拉索单元预张力和周边桁架单元横截面积为设计变量，以天线反射面精度、结构最低固有频率、频率禁区以及结构强度等为约束，以结构重量(或质量)为目标函数。 5．针对周边桁架式可展开天线动力优化模型具有高非线性、设计变量类型复杂、求解规模大等困难，提出了将遗传算法(GA)引入可展开天线动力优化设计中的思想，利用改进后的遗传算法对优化模型进行了优化计算，取得了合理的优化结果。 6．根据星载可展开天线具有结构两态性的特点，首次尝试了同时考虑两种状态—发射时的收拢状态和工作时的展开状态下的可展开天线动力优化设计，建立了同时考虑星载天线处于两种状态下的动力优化模型，并将其应用于实际天线的优化设计中，取得了合理的优化结果。 7．为解决周边桁架式可展开天线处于收拢状态时结构复杂，计算难度大的困难，提出了基于结构刚度等效准则的复杂结构简化计算方法，据此对可展开天线处于收拢状态时的结构模型进行了简化处理，建立了相应的计算模型，推导了结构参数的等效计算公式，并对各材料参数对结构特性，特别是结构动力性能的影响做了较深入分析。 8．比较了三种星载天线常用拉索布局类型的特点，分析了拉索系统布局改变西安电子科技大学博士学位论文对结构精度、天线重量以及结构动力性能的影响。建立了可展开天线的布局优化数学模型，该模型以天线拉索系统中上、下悬索数量、以及中间调节索数量作为设计变量，在优化过程中同时考虑结构的精度约束和结构重量约束，并通过算例对模型进行了验证。 本文第二部分关于工程结构系统优化的研究工作得到了国家自然科学基金项目一大型天线结构系统优化设计的支持，文中对结构系统优化设计进行了初步的探讨，取得了一些有益的结果。主要包括以下几个方面: 1.提出了基于遗传算法思想的结构系统优化方法，将各类设计参数(结构类型、结构拓扑、形状及截面变量)统一考虑，使得设计人员能够完成对结构各层次变量的同步优化设计。 2.分析比较了拓扑优化设计中存在的两类方法一进化法和退化法的特点，针对现有进化法存在的问题，提出了一种新的进化式布局优化设计方法一三角网格进化法，通过数值实验验证了该方法的有效性。 3.首次提出将结构类型作为设计变量，建立了结构类型优化设计模型，数值试验结果说明了模型与方法的正确性与有效性。 4.首次提出了结构支撑优化问题，将结构支撑条件划分为支撑位置优化和支撑类型优化两个层次，提出了结构支撑条件优化设计的策略与方法，并将其应用于典型数值算例的计算，取得了合理的结果。 关键词:等效模型可展开天线索网结构几何非线性等效模量布局优化系统优化拓扑 动力优化遗传算法类型优化支撑条件更多还原

【Abstract】 The research work in the paper is composed of two parts: the dynamic optimization of the deployable large flexible net antenna for satellite and the systemic optimization design of structure. The research work about the dynamic optimization of the deployable large flexible net antenna will be introduced as follows:1. In the paper, the research developments of satellite antenna are surveyed, which include its history of development and characteristic. The deficiencies and existent problems of study to deployable antenna are discussed, especially in dynamic optimization of deployable antennas. The significance about the research is pointed out.2. A classification is made to deployed antenna according to the difference of antenna reflector and the deploying force. This paper introduces applications of some new material in deployed antennas and forecasts the developments about satellite antenna.3. Considering the flexible cable net deployable antenna, the author have derived the nonlinear static analysis and dynamic analysis formulation of the tensegrity space structure and presented the calculation method. The dynamic properties of the structure are investigated by calculating a real example.4. The effects of pre-stressed cable, structural mass and the size of cable on shape accuracy and dynamic properties of the flexible cable net deployable antenna have been studied. The paper presents an optimum design model searching for minimum weight design with the constraints such as reflector precision, eigenfrequency, strength and forbidden frequency domain. The design variables include both the cross-sectional area of truss and stress of cable.5. The characteristics of the dynamic optimum design model of the deployable antenna are discussed, which is the highly nonlinear problem in terms of constraints and cable structure itself and the more complex problem for two kinds of variables, cross-sectional area of truss and stress of cable. To solve the difficult problem, an improved GAS is proposed by the author and used to deal with the problem.6. Based on the characteristic that the deployable antenna takes on two states, deployed state in the orbit of space and folded state in the freight rocket, an dynamic optimum design model is presented for the first time. The model is of pretty difference from the model with ordinary one for that it is a highly nonlinear problem and it is of two different states; i.e. deployed and folded states. The model is applied to a practical satellite antenna with good and useful results, which shows the validity of themethodology.7. It can be noted that the finite member analysis on the antenna structure in folded state is pretty difficult for its complexity. To solve the problem, the author presents a new method based on equivalent rigidity to deal with the structure with folded state. A simple effective modulus is founded. The effects of several material parameters on dynamic properties of the structure have been discussed.8. Considering the new flexible cable net deployable antenna, the author discusses the optimum design of cable system. An optimum design model is presented searching for minimum weight design while the constraints such as reflector precision is concerned. The design parameters are the number both of upper cable, below cable and adjustable cable. Through a numerical example, the theory above is tested to be correct and effective.The secondly research work is the systemic optimization design of structure. The followed work haven been done:1. The systemic optimum method based on GAS has been presented, in which the design variable is composed of topology, configuration and cross-section parameters simultaneously.2. This paper presents a new automatic truss layout optimization method. The method can grow least-volume trusses starting from the simplest layout rather than from a complex ground structure. The method has the advantage that it allows a structure to grow and degenerate towards an optimum topological layout.3. The type optimization was discussed for the first更多还原