A Seismic Reduction System For The Hollow Floor Nonlinear Structure And Research On Structural Vibration Control

Seismic and wind resistance of building structure has been the focus of structural engineering research for years,people are committed to finding new structural control methods and devices for structural control.The hollow floor structure is widely applied for its advantages,including of less material,construction convenience,good seismic performance,thermal insulation and others.In this paper,the cavity floor TRMD system is proposed.It is a new type of vibration system,which applies a ball damper device to hollow floor structure.The system make full use of the inner space of the floor to make a arc path,the ball will rock back and forth under seismic or wind excitation.Because of the friction between the ball and the rail,the absorber can absorb vibration energy of the structure,thereby reducing by dissipative structure principal energy under the action of earthquake,so as to achieve the effect of vibration control.The analytical solution of linear structure TRMD controlled system under harmonic excitation has derived by harmonic balance method,agree with the results of numerical simulation.And the frequency response function of the system can be obtained.When the excitation frequency is close to the structure frequency,TRMD can significantly reduce the displacement response of the primary structure,compared with uncontrolled system.Considering the fact that structural material will become nonlinear under large earthquake excitation,the motion equation of the TRMD control system of the Bouc-wen nonlinear structure is derived.Based on the equations,the energy consumption effectiveness of the absorber and itself hysteretic characteristics are studied under harmonic excitation and for a variety of historical records of strong earthquakes TRMD control effect of nonlinear structure is studied.The results showed that,TRMD can effectively reduce the structure's displacement,but at the same time,the structural hysteretic energy dissipation capacity is reduced,while the total energy dissipation capacity of the structure is increased.For some seismic excitation,the control effect of TRMD on nonlinear structure is quite obvious,but because of the variety of seismic excitation spectrum characteristics,the difference between the TRMD and the main structure displacement can be large as well.Because of the random characteristics of earthquake excitation,the effect of TRMD is not consistent with the different seismic excitation,it is necessary to analyze the random dynamic response of the control system.Based stationary white noise stochastic model,Bouc Wen hysteresis nonlinear system with and without TRMD is analyzed and compared by Monte Carlo simulation,the results show that: TRMD has obvious reduction effectively for Bouc-wen hysteretic structure,while it can significantly shorten the time for unstable structure vibration.The nonlinear systems equivalent linear stiffness and damping parameters can be identified through the statistical linearization techniques.Based on the equivalent linear control system of the Bouc-Wen hysteretic nonlinear structure,we can calculate the dynamic response of nonlinear systems.Contrast with the results of Monte Carlo simulation,it can be quit agreeable.At the same time,the statistical linearization technique can significantly speed up the computation speed of the nonlinear system stochastic response analysis,which lays the foundation for the parameter optimization of the TRMD control system with Bouc-wen nonlinear structure.