Research On The Inter-story Isolation Structure Of AP1000 Nuclear Power Plant And Its Damping Performance

Due to the frequent and random nature of earthquakes,improving the seismic level of nuclear power plants is one of the important aspects of ensuring nuclear energy safety.In recent years,seismic isolation technology to reduce the transmission of seismic energy to the structure has gradually entered the field of structural design.However,due to the complexity of nuclear power engineering structures,seismic isolation technology is rarely used in nuclear power plants.The AP1000 nuclear power plant is taken as the research object in this paper,and the inter-story isolation structure of nuclear power plant is proposed by introducing layer-isolation technology.Meanwhile,the damping performance of inter-story isolation structure is studied.The specific research contents are as follows:(1)Based on the basic principle of inter-story isolation,combined with the structural characteristics of the AP1000 nuclear power plant,the inter-story isolation structure is established by modifying the fixed connection of air intakes to isolation bearings,and the advanced seismic design concept of the inter-story isolation structure is explained.(2)The simplified analysis model of the AP1000 nuclear power plant is established,and the seismic excitation model and energy balance equation of the inter-story isolation structure are constructed.The energy consumption index was used as the optimization target to optimize the parameters of isolation layer.In the frequency domain,the damping performance of seismic isolation structures with different mass ratios is compared and analyzed.(3)The ANSYS overall finite element model of the AP1000 inter-story isolation structure is established,and the dynamic characteristics and seismic responses of the inter-story isolation structure with different mass ratios under the action of nuclear power artificial seismic waves are compared and analyzed.The impact of inter-story isolation technology on the floor spectrum of the internal equipment of the nuclear power plant is also discussed.The research results show that the inter-story isolation technology has a good damping effect,which can significantly reduce the dynamic responses of nuclear power plant under the action of earthquake.At the same time,the increase in mass ratio is beneficial to improve the damping performance of the inter-story isolation structure.The research results provide theoretical support for improving the seismic safety of nuclear power plants.