High Performance Control Of Structural Seismic Response

Taking into account the mass amplifying mechanism of the inerter,by integrating the tuned tandem mass dampers(TTMD)with two inerters,the tuned tandem mass dampers-inerters(TTMDI)with high performance has been proposed firstly for the control of structural seismic responses.This dissertation carries out an in-depth research from three aspects including the basic characteristics of the TTMDI,TTMDI based seismic response control of multi-degree of freedom(MDOF)structures,and performance boost of base-isolation system(BIS)using TTMDI,respectively.The main work and research achievements are as follows:(1)The basic characteristics of the TTMDI system with high performance has been investigated.Employing the closed-form expressions of dimensionless displacement variances for the structure-TTMDI system,the evaluation on the performance of the TTMDI has been made including the control effectiveness,mass block strokes,optimum stiffness and optimum damping coefficients,optimum distributions of the inertance coefficients,optimum frequency spacing,as well as frequency responses of the controlled structure.For the purposes of further comparison,the optimum results of the TTMD and tuned mass damper-inerter(TMDI)are also included into consideration.Results clearly demonstrate that the TTMDI has advantages of smaller size,higher effectiveness,stronger robustness,simplicity,and easier implementation.(2)The seismic performance of the MDOF structure-TTMDI system has been explored in the frequency domain.Considering the frequency-dependent power spectrum model of earthquake ground acceleration and different TTMDI topologies,the extended state space equation and H2 norm of each transfer function are established for the MDOF structure-TTMDI system.The seismic behaviors of the MDOF structure-TTMDI system have been analyzed from several aspects including the control effectiveness,mass block strokes,inertia forces,optimum distributions of the inertance coefficients,and optimum stiffness and optimum damping coefficients.Furthermore,the recommended values of total mass ratio and total inerter mass ratio,as well as best topology have been given finally.(3)Analysis of seismic responses of the linear and non-linear MDOF structure-TTMDI systems has been made.The evaluation criteria for the damping effect of control devices are defined using the peak values and root mean square of structural dynamic responses.Employing the established Simulink model of the linear and nonlinear MDOF structure-TTMDI system and the selected seven near-field and seven far-field seismic records,the control performance of TTMDI system for linear and nonlinear MDOF structures is evaluated and compared with the TMD and TTMD with large mass and with approximate same effectiveness in the frequency domain,the TTMD with the same mass,as well as the TMDI with the same mass and same inerter mass.Results indicate the TTMDI with small mass is capable of reaching approximately the same control effectiveness of the TMD and TTMD with 10 times mass than it;meanwhile,dramatically reduces its strokes.(4)The seismic fragility of MDOF structure-TTMDI system has been assessed.Firstly,the original data of seismic fragility curves of structures are obtained by the incremental dynamic analysis(IDA).Secondly,the probabilistic seismic demand model(PSDM)is determined by the probabilistic seismic demand analysis(PSDA).The transcendental probability function of the structure is thus obtained under different ground motion intensity levels,drawing the seismic fragility curves of the structure.Finally,the seismic fragility assessment of the MDOF structure-TTMDI system is made.This assessment manifests the TTMDI can reduce the damage probability of structures under earthquakes with different features,preferably.(5)Further,the BIS+TTMDI system with high performance has been proposed.The transfer functions,optimization objective function,and performance evaluation index are established of the BIS+TTMDI system.In the frequency domain,the performance of the BIS+TTMDI system has been explored under the different combination of total mass ratio and total inerter mass ratio,as well as the different characteristics of isolation layers.Likewise,the optimum results of the BIS+TMD,BIS+TTMD,and BIS+TMDI systems are also given for a further comparison.At the same time,the seismic response analysis of the three-story structure with a BIS+TTMDI system under different earthquakes has been implemented in the time domain.Likewise,a comparison among the uncontrolled BIS,BIS+TTMDI,BIS+TMD,BIS+TTMD,and BIS+TMDI systems has been made.Analysis in the frequency domain and time domain shows the BIS+TTMDI not only maintains a good control effectiveness to superstructure,but also significantly diminishes the displacement of isolation layer.Otherwise,it is stronger robust to the uncertainty of seismic features.