Research On Vibration Control Of Rotational Inertial Tuned Mass Damper In Isolated Structures

Earthquake is one of the most common natural disasters,so it is important to strengthen vibration control of structures.Base isolation is a commonly used and effective method to reduce the earthquake action on the superstructure.In the base-isolated structures,the displacement caused by the earthquake is mainly concentrated in the isolation layer,and the displacement of the isolation layer may exceed the limit value.In order to reduce the isolation layer displacement,this thesis proposes an enhanced base isolation system,which is based on conventional isolation system series rotational inertial tuned mass damper(RITMD).Compared with traditional TMD,RITMD can effectively reduce the mass of the control system and have better control effect.In this thesis,the vibration control effect of RITMD in isolated structures is studied.The main research contents are as follows:(1)This thesis introduces the working mechanism of RITMD.The displacement response function of single-degree-of-freedom RITMD control structure under base harmonic excitation and white noise excitation is deduced.MATLAB is used to optimize the RITMD system parameters.The comparison shows that the optimal frequency ratio under harmonic excitation is smaller than that under white noise excitation,while the optimal damping ratio is on the contrary.(2)Time-history analysis of seismic response of the single-degree-of-freedom RITMD control structure is carried out by using MATLAB programming.The calculation results show that the control effect of RITMD system is about 30% higher than that of TMD system.(3)Time history analysis of seismic response of the four-layer steel frame structure is carried out by using matlab programming.The results show that RITMD can effectively reduce the seismic response of the isolated structure,and the control effect of the isolation layer is better than that of the superstructure.When the mass of RITMD is one third of traditional TMD,the control effect is improved by 20% ～ 30%.(4)The robustness of RITMD in the control of isolated structure is analyzed by considering the change of structural isolation layer stiffness,control system parameters,and seismic wave.The results show that RITMD has good adaptability and robustness.