Seismic Performance Analysis And Optimization Design Of Nuclear Power Door

In natural disasters,earthquakes can cause unpredictable risks to nuclear power plants,so the impact of earthquakes must be considered in the design and construction of nuclear power plants.Nuclear power door is a maintenance structure isolated or connected to the outside world in nuclear power plant or nuclear power building.If the nuclear power door is damaged,it will cause casualties and leakage of harmful substances.Therefore,it is very important to analyze the seismic performance of nuclear power door.The types of nuclear power doors are diverse,and their structural forms and materials are also different.Therefore,seismic analysis should be carried out according to the vibration characteristics of nuclear power doors.In this thesis,different seismic analysis methods are introduced.The seismic performance of nuclear power door is studied by finite element calculation,and its reliability under earthquake action is verified.According to the analysis,it is optimized and strengthened.The specific research contents are as follows :(1)Review and sort out the research status of seismic performance analysis of nuclear power plants,nuclear power equipment and nuclear power plant doors,and analyze the significance of seismic analysis of nuclear power doors.The basic concepts used in the seismic analysis of nuclear power doors and how to choose the appropriate seismic calculation method are explained,and the process of seismic analysis of nuclear power doors is given.(2)Two different types of nuclear power doors,biological screen door and electric drive hinge door,are introduced.Combined with their structural characteristics,the finite element calculation model is established by ANSYS software.The vibration characteristics are analyzed after the natural frequency is obtained by modal calculation.Combined with the working mode,load requirements and working conditions of nuclear power doors,a finite element seismic calculation method for these two nuclear power doors is formed.(3)Do static analysis and stress assessment under the condition of nuclear power door dead weight to ensure that the door meets the design requirements.The strength analysis of SL-1 and SL-2 under seismic load is carried out,including the principal stress distribution of steel structure and the shear and tensile stress distribution of linear members.According to the evaluation requirements,the stress check of the structural members of the two nuclear power doors under earthquake is carried out.According to the stress evaluation results and structural characteristics of the nuclear power door,it is strengthened to ensure that the structure meets the stress requirements and has a certain margin.(4)This thesis introduces genetic algorithm to optimize the structure of nuclear power door.Taking the structural lightweight as the objective function,and according to the relevant design specifications and structural characteristics to determine the constraints,the optimization design is carried out.The optimized results show that the weight of the two nuclear power door structures is reduced by 8.9 % and 11.3 % respectively compared with that before optimization.The optimized model is subjected to nonlinear finite element analysis under two seismic conditions and compared with the results before optimization.The results show that the maximum stress is less than the results before optimization,and the deformation meets the requirements,indicating that the optimized design scheme is effective.And the strength of the structure better improves the stability and safety of the structure.