Simulated Research On MR Intelligent Semi-active Control Of Flow-induced Vibration Of Hydraulic Arch Sluice

Hydraulic arch sluice is one of popular types of gates applied in hydraulic projects because of light structure and easily operation. But, meanwhile, arch sluice vibration can be easily excited by fluctant water pressure due to relative little stiffness and damp. In the case of small opening and submerged discharge, if rubber seal system of arch sluice damaged (the usual type of damage for arch sluice), the interaction between water and sluice may cause intensive structural vibration so as to result in arch sluice damage at last. Improving hydraulic boundary condition and optimizing arch sluice structure are very important measures to reduce the vibration, but these measures which can only be taken before construction are not enough for reduction of the vibration. Employing structure control method is a further possible and new way to solve the problem duo to the development of intelligent material and control technic. This method is significant for vibration mitigation of already existing arch sluice. In this paper, an arch sluice of a diversion bottom outlet in certain large hydro junction is taken into account. Based on simplified 3-dimension structural model and simulated time-history fluctuant pressure, several "on-off energy dissipation" intelligent semi-active control strategies are investigated in order to reduce the vibration of the arch sluice installed with MR dampers.Realization of vibration control of the harmful flow-inducinn vibration of arch sluice needs simplification of sluice model. Three-dimensional finite element method is used to calculate the structural dynamic properties, and the principle of equivalent dynamic properties is adopted to modify the simplified mechanical model of arch sluice. Three-dimensional simplified structure model and its system parameter of the equivalent arch sluice are determined. The results of analysis and calculation show that the simplified three dimensional mechanical model can reflect the dynamic properties of arch sluice structures and the vibration reaction of stochastic pulse pressure. Therefore, it can be used in the intellinent control desinn of arch sluice installed with dampers.One of the key problems in flow-Induced vibration analysis of radial hate is to determine the stochastic fluctuant pressure. According to experimental result and relative field surveying data, the genetic algorithm is applied to simulate stationary time-history fluctuant pressure which causes intensive vibration of the sluice. Meanwhile, time variable AR modeling of nonstationary time-history fluctuant pressure is developed. This modeling method assume that time variable parameters are Markov process. Time variable parameters can be obtained by employing maximum likelihood optimization, filtering and fixed interval smoothing algorithms. These jobs provide a condition for time-history analysis and further control analysis.Fuzzy logic control (FLC) is one of intelligent control methods in structural control, especially suitable for control system with no exact mathmetical model,...