Research On The Semi-Active Control Of Eccentric Structure With EIMD

Under the action of earthquake,the eccentric structure does not coincide with the center of mass and the center of stiffness.The inertial force acting on the mass center generates torque to the core,forcing the structure to undergo translational torsional coupling vibration,resulting in large torsional deformation.Previous earthquakes have shown that the torsional coupling reactions of structures under earthquake have became the key factor in structural damage.The traditional method uses the structure itself to reduce the earthquake disaster,while the structural vibration control technology uses the non-load bearing structure control device to reduce the disaster response of the structural body.Along with times developing,structural vibration control technology can be divided into four main aspects: passive control,active control,semi-active control and intelligent control.Compared with other control technologies,semi-active control has the advantages of low cost,good effect and easy implementation and can obtain good control effects under the condition of less energy from outside.Therefore,the study of semi-active control of eccentric structures is of great significance in the field of structural earthquake resistance.Compared with traditional damper,electromagnetic inertial mass damper has attracted much attention in recent years due to its high precision,low frictional resistance,easy maintenance,long system life and low environmental pollution.What's more,the electromagnetic damping force of EIMD can be controlled by the terminating resistor,so EIMD can also be used as a semi-active damping device.In this paper,a semi-active control system based on LQR control algorithm was put forward based on the New Electromagnetic Inertial Mass Damper(EIMD).The method of arranging the position and quantity of EIMD based on genetic algorithm was studied in order to improve the control efficiency of the damper and reduce the cost.Finally,considering the impractical condition to install too many sensors in complex structures to measure the whole state of the structures,the LQG active control algorithm combined with the semi-active control strategy was used to analyze the theoretical calculation results of the eccentric structure based on the genetic algorithm.The main work of this paper is as follows:(1)The basic working principle and mechanical properties of EIMD were expounded.The basic structure of EIMD with scale and full scale was introduced.The relationship between the damping and damping force of the damper was obtained.Taking a three-layer structure with a scale EIMD as an example,the damping performance of the damper was verified.The results show that the EIMD has better control effect when the external resistance is smaller,and the damper has good damping performance.It also shows that the EIMD can be used as a semi-active control device.(2)Taking a 24-layer eccentric structure as an example,a semi-active control strategy based on LQR was proposed for eccentric structures.Then two different seismic waves were input to the eccentric structure to verify the stability of the method.The simulation results show that the semi-active control of the eccentric structure based on LQR algorithm under different seismic waves had obvious inhibition on the displacement,rotation angle,acceleration and angular acceleration of the structure compared with the uncontrolled control.The effectiveness and stability of the method were proved.(3)In order to reduce costs and improve the control efficiency of the EIMD damper,the method of arranging the position and quantity of EIMD control system based on genetic algorithm was studied.Semi-active control analysis was carried out on the eccentric structure of different quantities of EIMD.The control effects of various dampers on the structure were compared.The simulation results verify the effectiveness of the genetic algorithm.(4)In order to reduce the number of sensors in the structure,the semi-active control algorithm based on LQG was used to analyze the calculation results of the optimized configuration.The simulation results show that the method could estimate the structural motion more accurately,and its control effect is close to the LQR control method.