Parameter Identification Method And Experimental Verification Of Structure-Frequency Modulation Vibration Reduction System

With the rapid development of national economy,high-rise structures have been widely used in various projects.Because of its light weight,high flexibility,small damping and other main characteristics,in order to prevent the towering structure in the service process of damage,damper is generally installed in its structure response is large,to suppress the structural response.Tuned Liquid Dampers(TLD)have become a popular vibration control device in contemporary tall structures,tuning the natural frequency of THE TLD close to that of the main structure to suppress excessive vibration due to environmental loads.In practice,the TLD can be assembled on-site at the same time as the construction of the structure,but in this case,the respective dynamic characteristics of the TLD equipment and the structure cannot be determined.However,current studies rarely identify ring TLD structures.Therefore,this paper focuses on the characteristic parameters of any two complex modes of the TLD system of modular buildings to carry out the research on ring TLD parameter identification.The main work and achievements of this paper include:(1)Based on the mathematical model of random subspace and equivalent mass stiffness model,the structure-TLD single-degree-of-freedom mathematical model is established,and the relevant parameters of TLD are calculated by extracting eigenvalues and eigenvectors.Finally,TLD recognition was studied and compared under the action of single-DOF TLD under different environmental excitation.The results showed that: Under different excitation conditions,the recognition error will change,and the recognition error is the largest under the earthquake action,which may be caused by the uneven distribution of the response frequency under the random action.(2)On the basis of single degree of freedom,the identification results of multiple degrees of freedom are studied and compared.Based on white noise excitation,the influence of the degree of freedom of the main structure on the parameter identification of the vibration reduction structure is studied.The results show that the identification accuracy increases with the increase of the degree of freedom.Then,the influence of different excitation types on parameter identification of vibration absorption structure system is studied and compared.The results show that: under the action of different excitation conditions,the maximum identification error of three-DOF system is under the earthquake action.The maximum recognition error of the 5-Dof system is under seismic action.The maximum identification error of the seven-degree-of-freedom system is in the case of earthquake action.It can be seen that under different excitation conditions,the largest identification error is in the case of earthquake load,although the error is large,but also within the acceptable range.(3)Based on single-DOF and multi-DOF systems,extending to high-rise structures,an online monitoring test model of high-rise structures is designed.An acceleration sensor is arranged at 11.5m and 21 m of the high-rise structure to measure the structural acceleration response.Four shear sensors are arranged at the bottom of the TLD tank to measure the change of shear force at the bottom of the TLD tank.Two wave height meters are arranged in the annular TLD water tank to provide a basis for subsequent verification of TLD parameter identification results.An anemometer is placed on top of the towering structure to monitor wind speed and wind Angle.In addition,an online health monitoring system is designed for high-rise structures to provide corresponding data support for subsequent TLD parameter identification studies.