Seismic Response Analysis Of The Primary-secondary Coupled System With Base Isolation

In recent years,base isolation technology has been rapidly developed and widely used in engineering.In some industrial buildings,the base isolation technology is adopted to reduce the damage of the industrial equipment.There is a complex dynamic interaction between the primary structure and the industrial equipment.Based on the conclusion of primary-secondary coupling system conclusion,the seismic response of the primary-secondary coupled with base isolation is analyzed.It has important theoretical significance and engineering application value for the seismic design of industrial buildings and industrial equipment.The series double degree of free model,multi degree of free model and dynamic equations of the coupled system are established,and through frequency domain analysis to study of he effects of the frequency ratio and mass ratio on the dynamic characteristics in double degree of free model.The input power spectrum,the random seismic response analysis of primary-secondary coupled system with base isolation and the effects of the frequency ratio,mass ratio and damping ratio of isolation layer are studied.Optimizing the frequency of primary structure and damping ratio of isolation layer to realize the optimal vibration isolation of the primary-seconday system with base isolation.Research shows that the frequency ratio and the damping ratio of isolation layer is the main parameters influencing the response of the system,the frequency ratio at 0.56~0.63 and the damping ratio of isolation layer between 0.8~0.98,the response of the whole system can be effectively controlled,with little change in mass ratio.The seven storey reinforced concrete frame structure industrial buildings as an example,using finite element analysis software SAP2000 to establish the base isolated light industry workshops model and non base isolation model analysis of seismic isolation effect.Research shows that the plan has a base good damping effect,under the action of horizontal earthquake,the seismic response of the primary structure and secondary structure is greatly reduced by large deformation in the seismic isolation layer.The influence of the location of the secondary structure,the stiffness of the isolation layer and the damping ratio of the isolation layer on the seismic response of the primary-secondary coupled system with base isolation is studied.The results show that the secondary structure location has little influence on the seismic response of the secondary structure after the primary structure base isolation.The stiffness of the isolation layer is favorable to reduce the seismic response of the primary structure and secondary structure.Increasing the damping ratio of the isolation layer is favorable to reduce the deformation of the isolation layer,which has an adverse effect on the secondary structure when the damping ratio of the isolation layer exceeds a certain limit value.