Fuzzy Reliability Analysis Of Gate Valve Based On GA-BP

The manufacturing error of gate valve structure size and the fluctuation of load have an important influence on the stress of valve structure,and these uncertainties are inevitable in the process of valve production due to the influence of process level,personnel operation ability and other factors.Therefore,considering the influence of the above uncertainties in the design work can improve the safety performance of gate valves more comprehensively.Based on the structural reliability theory,this paper calculates and analyzes the reliability of gate valves under design conditions.In view of the defects of the maximum stress prediction model in the reliability calculation of gate valves,this paper carries out a study based on the legacy Study on maximum stress prediction model of gate valve based on neural network optimized by transmission algorithm.The explicit expression of the maximum stress of gate valve is obtained by the optimized neural network,and the expression is used in the subsequent reliability calculation.Compared with the traditional BP neural network model,the neural network model optimized by genetic algorithm can effectively improve the prediction accuracy and reduce the influence of mathematical model error on the accuracy of subsequent reliability calculation results.In order to further improve the accuracy of the reliability calculation results of gate valves,aiming at the fuzziness of gate valve strength,fuzzy design criteria are introduced into the reliability calculation of gate valves.Firstly,the neural network optimized by genetic algorithm is used to establish the maxi mum stress prediction model,and the implicit relationship between the maxim um stress of gate valve body and the size and internal pressure of valve body is changed into an explicit relationship Then,the reliability of gate valve under conventional method is calculated by Monte Carlo method Finally,the fuzziness of gate valve strength is described by normal membership function,and the reliability of gate valve is calculated when fuzzy strength is considered.By comparing the reliability calculation results before and after considering fuzzy strength,the influence of strength fuzziness on reliability calculation results is analyzed.Compared with the traditional random reliability calculation method,the fuzzy reliability calculation method is more reasonable in describing uncertainty and more accurate in calculating reliability in theory.