Reliability Analysis Of Chain-type Magazine And ATC Based On Bayesian Network

According to the national science and technology major project,the chain tool magazine and ATC of a series of horizontal machining centers made in China are taken as the research object.The chain tool magazine and the ATC Bayesian network model are established by using FMEA and SADT technology.Based on evidence theory,the root node failure rate interval can be determined.Based on Bayesian reasoning,the reliability analysis of chain tool magazine and ATC is carried out to determine the weak links,which lays the foundation for achieving the reliability growth of products.First of all,the chain tool magazine and ATC working principle of a series of horizontal machining centers made in China are analyzed.They are divided into parts,and the FMEA method is used to get the relationship between parts and subsystems.Based on this,the SADT model is established by using structural analysis and design technology.Based on mapping relationship between models,SADT model is transformed into chain tool magazine and ATC Bayesian network model.Secondly,aiming at the uncertainty of the failure rate of the root node of the Bias network caused by missing data in chain tool magazine and ATC,the evidence theory is applied to integrate reliability information such as design,manufacturing,assembly and use.Using likelihood function and trust function to express the upper and lower limit of component failure rate interval,the root node failure rate interval in Bayesian network is calculated.Finally,on the basis of chain tool magazine and ATC Bayesian network model and root node failure rate interval,combined with Bayesian forward direction and reverse reasoning technology,the fault rate interval of chain tool magazine and ATC system and the posterior fault rate interval of components represented by each node are determined.Through the analysis of root node importance,posteriori failure rate analysis,leaf node failure rate analysis and dynamic analysis based on discrete time Bayesian network model,the weak link of reliability is determined,and the direction of reliability improvement is pointed out.