Theoretical Analysis And Shaking Table Tests On A Torsional Servomotor Active Tuned Mass Damper System

Earthquake is a natural disaster that cannot be accurately predicted and is extremely destructive,which can cause huge economic losses and casualties to human society.Active Tuned Mass Damper(AMD)is an active control system that can significantly improve the disaster resistance performance of the structure.Compared with the traditional hydraulic servo AMD system,the torsional servomotor AMD system has attracted the research enthusiasm of a large number of scholars due to its relatively low cost,smaller installation space,and easy maintenance.The application of torsional servomotor AMD control system involves the crossover problems of many disciplines,and there are many unsolved problems need to be overcome.In particular,there are few studies on the integration,unification,real-time online control ability,Establishment of active control algorithm in control system and shaking table test on torsional servomotor active control system.This paper mainly focuses on the theoretical and experiments studies for the damping performance of the torsional servomotor AMD control system during structural vibration process.The main research contents and conclusions are listed as follows.(1)The motion equation of the structure considering the electro-mechanical relationship of torsional servomotor are established,and the structure vibration response with three different control modes(uncontrol,TMD control,and AMD control)is compared.The results show that the AMD control system can effectively control both the first-order and second-order modal vibrations of the structure.(2)The reliability and stability of the active control system in the shaking table test are verified by the modal parameter identification test of the controlled structure and the performance test of the torsional servomotor AMD control system,which lays a foundation for the completion of the subsequent shaking table test.The results show that structural mathematical model from the modal identification test can reflect the dynamic characteristics of the structure accurately.And the torsional servomotor can perform well in structural vibration control.(3)A shaking table test was carried out on the three-story steel frame structure with torsional servomotor AMD control system.An open active control system based on Lab VIEW software platform was developed.The control performance of the AMD control system on structural vibration is investigated under different seismic excitations,the same seismic record with different source distances(near-filed,mid-far-field,and farfiled),and different weight matrices in the linear quadratic regulator(LQR)optimal control algorithm.The results show that the AMD control system has a significant control effect on the structure response,the first-order and second-order modal vibration responses of the structure is significantly reduced,and the damping performance of the structure has a great increment.Furthermore,for the structural optimal active control matrix Q,the active control effect of the structure is reduced no matter its value is increased or decreased.(4)Based on shaking table test,numerical simulation is extended to study the influence of Kalman filter parameters and LQR active control parameters on the active control effect of structural vibration in AMD control system.The results show that the parameters in the Kalman filter have an obvious effect on the active control.Moreover,the effect of structural active control is related to the ratio of weight matrix Q and R in LQR control algorithm.(5)Because of the structural torsion observed in shaking table tests,the AMD control system which can control the horizontal and torsional coupled vibrations of asymmetric structures is designed and the control effect is analyzed.The feasibility and effectiveness of the fuzzy neural network control algorithm to replace the LQR control algorithm are simulated and verified.The results show that the AMD control system can effectively control the horizontal and torsional vibration of the structure.Furthermore,the fuzzy neural network control has a better application prospect.