Research On Seismic Analysis Of Overhead Crane For Nuclear Power Station

With the development of economy,the proportion of nuclear power in China’s power system is increasing.Bridge crane is a common material handling and hoisting equipment in nuclear power plant,which belongs to class II seismic equipment related to nuclear safety.In order to avoid serious nuclear accidents caused by falling parts of bridge crane in earthquake,bridge crane must meet the requirements of seismic performance.In seismic design,it is necessary to refer to foreign or domestic codes for seismic design of hydraulic structures,buildings and bridges.This paper introduces the static seismic method of iso1031:2016-modified seismic coefficient method,studies the application of modified seismic coefficient method in the seismic design of crane,analyzes the relevant parameters in the calculation process of modified seismic coefficient method,and makes a comparative study with the existing seismic design codes at home and abroad.In this paper,the 25 t bridge crane is taken as an example,and the modified seismic coefficient method,response spectrum analysis method and time history analysis method are used for comparative verification.Firstly,the finite element model of the bridge crane is established by Solid Works.The accuracy of the finite element model is verified by static analysis and theoretical calculation,and the seismic calculation of the bridge crane is carried out by using the modified seismic coefficient method.Then the modal analysis of different working conditions of the bridge crane is carried out,and the natural frequency,vibration mode and other parameters of the crane are obtained.According to the characteristics of the proposed site,the floor response spectrum is input to carry out the seismic response spectrum analysis of the bridge crane.The dynamic responses of key points of the crane are obtained by applying the adjusted EI Centro wave,Taft wave and artificial simulated seismic wave to the crane by using the time history analysis method.The analysis results show that under the same seismic excitation,the maximum stress in the middle of the bridge crane is 1.15 times,1.11 times and1.11 times of the static calculation,and the maximum displacement in the middle of the bridge crane is 1.15 times,1.11 times and 1.11 times of the static calculation.In ISO11031:2016,three seismic analysis methods are listed for seismic load estimation accuracy law: Time history analysis method > Maximum Response Spectrum Method > Modified Seismic Coefficient Method,based on the calculation and simulation and the rule of the same calculation results are obtained,the correction coefficient of seismic method to consider the position of the crane,the basic dynamic characteristics of seismic characteristics,crane,consideration is more comprehensive,for the seismic analysis of bridge crane has a certain reference significance.