Study On Vibration Control Of Isolated Continuous Beam Bridge Based On MR Damper Under Earthquake Excitation

In the modern traffic system,as an important infrastructure and urban lifeline,bridge is always the key to access ways and the evacuation passageway after the disaster,so it is very important for bridges to have certain conditions of passage and use function after the disaster,and it is necessary to develop more secure,more economical,more reliable and more effective structural system.The semi-active control devices of intelligent materials such as magnetorheological fluid have attracted the attention of researchers because of their good performance.In this paper,MR damper is used as the control device to control the vibration of Isolated Continuous Beam Bridge under earthquake excitation.The control effects under different control strategies and schemes are compared then,which provides theoretical guidance for the popularization and application of MR dampers.This paper firstly introduces the concept of structural vibration control,classification and current development in the field of engineering,focuses on the basic principle and engineering application of passive control,active control,semi-active control,hybrid control and intelligent control,and a brief introduction of MR damper.Secondly,this paper expounds the work performance of MR damper through the introduction of the MRF effect,and two common kinds of the dynamic model of MR damper are introduced,comparing the advantages and disadvantages,and introduces the research status of the newly self-powered or self-sensing MR damper.Thirdly,the Benchmark model of continuous beam bridge used in this paper is introduced,the analysis process of structural response is established by the derivation process of the nonlinear dynamic equation using Newmark-? method for the model,and several seismic waves are used to simulate the model,the corresponding analysis results are the basis of the control design in this paper.Then,the widely used Skyhook control algorithm in the field of vehicle and its modified algorithm are introduced in the semi-active control of bridge structure based on MR damper,after the corresponding control design,the structural response under different schemes are compared numerically,and the analysis results show that the semi-active control based on Skyhook algorithm or its modified algorithm can achieve effective vibration control for continuous beam bridge,including the SK scheme and the SK-Jerk scheme both have better performance against the M-SK scheme.Finally,combining with the different neural network theory,intelligent control strategies are proposed based on BP neural network and LVQ network respectively,and after control scheme design and numerical simulation,the analysis results show that the intelligent control based on BP network achieves the approximate effect of sample control in peak response control,and has an excellent performance in full-time control stability;the intelligent control based on LVQ network can effectively restrain the vibration response of bridge structure,especially in the control of base shear and overturning moment,and has a better performance than the traditional control scheme based on Skyhook algorithm as a whole.