Reliability Analysis Of Belt Conveyor Based On Improved FMECA And DFTA

As a long-distance continuous transport equipment,belt conveyors have widely used in many industries.Bescase of complex working conditions,the reliability of drive system is put forward higher.It is very important to study the reliability of belt conveyor during system design stage and maintenance stage.Due to the lack of traditional reliability analysis methods such as FMECA and FTA,the paper puts forward the application of improved FMECA and DFTA method to analyze the potential failure mode of belt conveyor and calculate the reliability of the system.And provide a basis for the development of maintenance strategies.The main contents and achievements of this paper are as follows:(1)Use ANSYS to analyze the strength of the drum of the belt conveyor under,and the stress and strain distribution of the drum were obtained.The stress of the roller shaft is more likely to be faulty.Increase the fillet radius angle to improve the roller shaft design.And the accuracy of the strength analysis of the roller finite element strength is verified by the fault analysis of the roller shaft of the belt conveyor.(2)To improve the traditional FMECA method that rely on the RPN value to determine the failure mode sorting,the study based on the fuzzy VIKOR FMECA method,the use of fuzzy evaluation language on the failure mode of the severity S,incidence O,difficult to detect D three risk factors The risk factors are calculated by using the VIKOR method,which avoids the problem that the same risk factor combination can not be sorted by the same risk factor combination,considering the weight of the three factors and the expert opinion,increasing the assignment accuracy.Based on the traditional FMECA method,determine potential failure modes and RPN of the three components(motor,drive drum and reducer)of the drive system.The improved FMECA method was used to analyze the hazard of the fault mode,when compared with the traditional FMECA method.The proposed methodimproves the accuracy in failure modes’ risk ranking.(3)For the traditional FTA can’t considere the dynamic sequence characteristics and the fault probability ambiguity uncertainty.In this chapter,use fuzzy number describe the fault probability,and bulid the dynamic fault tree analysis model of the belt conveyor drive system fault,Based on the qualitative analysis of BDD diagram,find the minimum basic event combination which leads to the system failure.Based on the Markov model,the fuzzy probability of the system is drawn and the reliability curve is drawn at some time.After the belt conveyor running for 1000h(about 41.7 days),the maximum probability of failure of the belt conveyor drive system is 0.887,which requires maintenance and overhaul,which is consistent with the actual survey.