Research On Random Vibration Analysis And Active

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 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...