Vibration Control Of Unascertained Intelligent Beam Structures And Prediction On Reliability Of Deployment Mechanism

Firstly, unascertained structures with random parameters, interval parameters are taken as research objects in this paper. The problem of structural dynamic characteristics, dynamic responses are derived under the conditions that physical parameters of materials, structural geometric dimensions and applied loads are all random variables, interval variables. Secondly, based on the engineering background of national 863 projects, reliability computation, prediction, analysis and assessment on deployment mechanism system of satellite antenna are derived by means of unascertained theory. The main research works can be described as follows:1. Dynamic response analysis of closed loop control system for random intelligent beam structures.This paper constructs a dynamic response analysis model for closed loop control system of intelligent beam structure with random uncertainties. The random approach is introduced for random dynamic response analysis of closed loop control system, with the Duhamel integral for dynamic responses and the Moment method for random variable function solutions, the numerical characteristic expressions are deduced for transversal displacement angle displacement and stress responses. Finally, an intelligent cantilever beam is taken as an example to explain the influence of random structural parameters and random loads on dynamic responses of closed loop control system, which also shows the feasibility and rationality of the random coefficient method.2. The analysis of dynamic characteristic of opened and closed loop system on interval intelligent beam structures.Structures with piezoelectricity intelligent beam are taken as research objects in this paper. According to the method of interval analysis, the interval model of mass matrix and stiffness matrices with the interval variables for structural physical parameters and geometric dimensions is built. From the Rayleigh quotient of dynamic characteristic of structural vibration, and based on the interval algorithms, the computation expression of structural natural frequency of open-loop system is obtained. Secondly, the finite element modeling of structural close loop system for dynamic characteristic analysis is established by displacement feedback control method, and the computation expression of structural natural frequency of close loop system is obtained employing Rayleigh quotient and interval algorithms. Finally, the effects of the uncertainty of structural interval parameters on structural natural frequency are inspected. In addition, the modeling and the method presented in this paper are verified through an example. The results illustrate that the interval coefficient method has important engineering value in dealing with the dynamic characteristic of the intelligent beam.3. The study of analysis method based on the correlation of interval parameters.Structures with unascertained piezoelectricity intelligent beam were taken as research objects in this paper. The problems of structural dynamic characteristic were derived under the condition that interval physical parameters were correlative. To ease the process of deducing, firstly, the computation expression of the interval variables were the interval coefficients by the certainly portion, and the interval coefficients were supposed to be allowable range, the random variables obeyed random rectangle distribution and random normal distribution in definition region. Secondly, The mean and variance of interval eigenvalues equations were deduced by the Moment method and Algebraic synthesis method for random variable function solutions under the condition that they were correlative each other. The bounds of eigenvalues were obtained by the mean and variance of rectangle distribution and the principles of "3σ"of Standard normal distribution. At last, the method presented in this paper was verified through an example. For comparisons, the corresponding eigenvalues ranges are obtained on the assumption that the interval variables were independent each other and the different of correlation coefficient. The results illustrate that the method has important reference value in dealing with the problems of structures reliability and the parameters designs.4. The probabilistic reliability prediction of the large-scale satellite antenna deployment mechanism system.Firstly, the deployment reliability of the frame rib of a large satellite antenna with hinged-rib was studied. By studying the difference of movement principium, a mechanical analysis model of the different contact of the cable and the hinged points were presented respectively. On this basis, two parallel performance function of according to rotation work and according to rotation moment were established respectively. Synthetically considering the effect of the random of dimension errors and the space environment factors, and derived the reliability formula by using the method of second-order moment. Finally, the rationality and the feasibility of the model were confirmed by an antenna with caliber of 12-meter. Furthermore, the theoretical basis and reference were provided for the deployment reliability of a large satellite antenna. Secondly, the deployment reliability of the Astro-Mesh of a large satellite antenna is studied. Finally, the rationality and the feasibility of the presented models are confirmed by an antenna with caliber of 17-meter, and some useful conclusions are obtained.5. The non-probabilistic reliability analysis of satellite antenna deployment mechanism system.Firstly, by studying the movement principium of the frame rib of a large satellite antenna with hinged-rib, the reliability movement-function as a function of some interval variables were presented. Synthetically considering the effects of dimension errors and the space environment factors, the movement reliability of the deployment mechanism was predicted and simulated in the whole process of deployment. Secondly, against the performance of the spacecraft mechanism and the possibility of the smaller sample test methods. With gears'machining tolerances and fitting allowances and the space temperature considered synthetically, from the ultimate position of the gearing mesh, according to the working condition of rated state and strengthen the state the gear pair seizure-preventing, the assessment model of reliability were obtained with the smaller sample test data. Finally, the feasibility and effects of the method were inspected through an example of project.