Perfomance-based Seismic Design Of Passive Energy Dissipation Structure With Shape Memory Alloy Damper

SMA damper developed by shape memory alloys can weaken the seismic response of structures,and reduce the residual deformation after the earthquake.Performance-based seismic design method could make the structure meet the different performance target under different earthquake,while it is widely concerned by the scholars.Performance-based seismic design of passive control structures could be used to determine the energy dissipation device easily,thus the seismic performance of structures could be improved to different performance objectives.The mechanical properties of SMA damper are numerically simulated based on mathematical model,and the displacement-based performance designs of SMA damper are carried out,which are achieved by time-history analysis(nonlinear dynamic analysis)and capability spectrum method(nonlinear static analysis).A five-story steel frame structure is selected for seismic performance design.(1)The numerical simulation of SMA damper is carried out based on mathematical model,and th Bouc-Wen model is the most commonly used mathematical model.According to the mechanical model of SMA damper,the Bouc-Wen model parameter identified,and the simulation analysis of damper is achieved in Simulink.Meanwhile,for the SMA dampers that have been tested,the force-displacement curve is obtained through simulation analysis.Three damper parameters and two parameter ratios are selected to study the performance of SMA damper.(2)The performance objectives of passive control steel frame structure are introduced,and the selection principle of SMA damper is improved.According to the relevant research results,performance standards and related interstory drift limits of passive control of steel frame are put forward.On the basis of the existing selection principle of damper,according to the characteristics of the SMA dampers,the selection principle of two parameter ratios is supplemented,and the ranges of parameter ratios are determined by the analyzed results.(3)The performance-based design method of passive control structure based on time history analysis is introduced,which includes the calculation of interstory drift reducing rate,sensitivity analysis of damper parameters,study of performance curves based on interstory drift reducing rate.The programs of passive control structure based on time history analysis are built in Simulink.In addition,a five-story steel frame structure is selected as an example for the seismic performance design.Time-history analysis and performance evaluation of the passive control structure with SMA damper are carried out.(4)The performance-based design method of passive control structure based on capability spectrum analysis is introduced,which includes the calculation of target performance point based on spectral displacement and equivalent damping ratio,obtain the additional damping ratio according to equivalent damping ratio.According to the mechanical model and energy dissipation characteristics of SMA damper,the formula of the additional damping ratio is proposed,and the damper parameters are determined by the additional damping ratio.Meanwhile,a five-story steel frame structure is selected for the seismic performance design based on capability spectrum method,performance analysis and time history analysis of passive control structure with SMA damper are carried out for performance evaluation.