【作者】 高伟；

【导师】 陈建军；

【作者基本信息】 西安电子科技大学 ， 机械制造及其自动化， 2003， 博士

【摘要】 本文以随机结构和随机智能桁架结构为对象，对结构动力特性分析模型与求解方法进行了研究；对结构在随机力或随机过程（平稳随机过程或非平稳随机过程）激励下，结构的动力响应、结构的振动主动控制、智能结构中作动和传感元件配置位置与闭环控制系统增益优化、结构参数对振动主动控制效果的影响等问题开展了全面而系统的研究。主要内容如下：1、考虑压电智能桁架结构主动杆单元及被动杆单元物理参数、几何参数同时具有随机性，基于随机因子法，构建了结构动力特性分析模型，提出求解方法，推导出结构动力特性随机变量的数字特征计算表达式。通过算例验证了理论和方法的正确性和有效性，为随机结构的动力响应分析提供了必要的基础。2、考虑压电智能桁架结构物理参数、几何参数、结构阻尼和外荷载、闭环系统控制电压分别或同时为随机变量，构建了结构在随机力作用下的动力响应分析模型，提出了求解方法，推导出结构动力响应随机变量的数字特征计算表达式，通过算例验证了所建模型和所提求解方法的正确性和有效性。3、利用随机因子法对随机桁架和随机刚架结构的动力特性进行了分析。在此基础上，从随机振动频域分析出发，导出了在平稳或非平稳随机激励下，随机结构的位移响应均方值、应力响应均方值的数字特征计算表达式，通过算例验证了所建模型和所提求解方法的正确性和有效性。4、同时考虑智能桁架结构的物理参数、几何参数、阻尼的随机性，构建了随机智能桁架随机响应闭环振动主动控制模型，分别以位移负反馈和速度负反馈为控制律，导出了随机智能桁架结构在平稳或非平稳随机激励下闭环控制位移响应均方值和应力响应均方值的均值、方差的计算表达式。研究了8米口径智能天线结构在随机风荷作用下其保精度闭环控制随机响应问题。5、对结构物理、几何参数、阻尼同时具有随机性，外荷载为随机力或随机过程力时，以速度输出负反馈作为控制律，采用智能结构的状态空间模型构建了基于最大耗散能准则的目标函数，分别建立了具有动应力、动位移可靠性约束的主动杆的优化配置和增益优化模型，和具有位移响应均方值、应力响应均方值可靠性约束的主动杆配置和控制增益的优化模型。利用分布函数法和可靠性安全系数法分别对可靠性约束进行显示化处理，使之转化为常规约束进行优化设计。对结构振动主动控制效果进行了计算机数字仿真，证明了所建振动主动控制模型的正确性与可行性，获得了若干对压电智能桁架结构振动主动控制有意义的结论。更多还原

【Abstract】 The stochastic structure and stochastic intelligent truss structure are taken as research object in this paper. The analytical model and method of the structural dynamic characteristic are investigated. When the applied forces are random excitation or random process (stationary random process or non- stationary random process) excitation, the structural dynamic response, the active vibration control for the intelligent structure, the optimal placement of the sensor and the actuator and the optimization of the feedback gains of the closed loop control system for the intelligent structure, and the effects of the structural parameters on the active vibration control et al are all studied systemically. The main research works can be described as follows:1. Considering the randomness of physics parameters of structural material, geometric dimensions of active bars and passive bars of the piezoelectric intelligent truss structure simultaneously, the analytic model of the structural dynamic characteristics are built based on the Random Factor Method (RFM). Then, the solving methods are proposed and the computational expressions of the numerical characteristic of the structural dynamic characteristics are developed. The correctness and validity of the theory and method presented in this paper are inspected by several examples, which are the credible base of the dynamic response analysis of stochastic structures.2. Considering the randomness of physics parameters of structural material, geometric dimensions, damping, loads and closed loop control voltage respectively or simultaneously, the analytic model of the stochastic structure under random forces are built. The solving methods are proposed. The computational expressions of the numerical characteristic of the structural dynamic response are developed. The correctness and validity of the theory and method presented in this paper are inspected by several examples.3. The dynamic characteristics of stochastic truss structures and stochastic frame structures are analyzed by using Random Factor Method. Then, from the expressions of structural random response of the frequency domain, the computational expressions of the mean value, variance and variation coefficient of the mean square value of the structural displacement and stress response under the stationary random excitation or non- stationary random excitation are developed by means of the random variable’s <WP=11>functional moment method and the algebra synthesis method. The correctness and validity of the theory and method presented in this paper are inspected by several examples.4. The closed loop active vibration control model for stochastic intelligent truss structures are built in which the randomness of physics parameters of structural material, geometric dimensions and damping are considered simultaneously. A neglect displacement feedback control law and a neglect velocity feedback control law are considered respectively, the computational expressions of the mean value, variance and variation coefficient of the mean square value of the closed loop control system of structural displacement and stress response under the stationary random excitation or non- stationary random excitation are developed. The problems of guaranteed precision of random dynamic response of closed loop system of 8-meter intelligent caliber antenna under random wind excitation are studied.5. A neglect velocity feedback control law is considered and the performance function is developed based on the maximization of dissipation energy due to control action. When structural physical parameters, geometric parameters and damping are all having randomness and applied loads are random forces or random process excitations, Then, the optimal mathematical model with the reliability constraints on structural dynamic stress and displacement response or the reliability constraints on the mean square value of structural dynamic displacement and stress response are construct. The reliability constrains are transformed as the normal更多还原