Research On Reliability Assessment And Residual Service Life Prediction Of Key Components Of Shield Machine Applied In Sandy Cobble Stratum

With the rapid and continuous development of China's underground tunnel construction in recent years,the ownership of shield machine,the main construction machine for tunnel construction,is also growing.The reliability of key components of shield machine is the most important index to ensure a normal tunneling operation.The reliability of key components of shield machine must be ensured strictly due to the extremely bad,complex and changeable working environment.So it is of great importance to carry out the study on reliability and residual service life of key components of shield machine.In this article,we will study the algorithm of reliability and residual service life of key components of EPB shield machine working in Chengdu sandy cobble stratum.The primary content in this paper involves:1.The fault failure types,assessment method of reliability and residual life of mechanical equipment are investigated based on a lot of literature summary,and method based on performance degradation data is chosen as the main research method of this article;2.Wear-resisting structure of cutterhead panel and the screw shaft are chosen as main research objects,and degradations are classified into two types,hard and soft.According to the two types of degradation,calculation models of reliability assessment and residual service life prediction are set up based on single point failure and competing failure;3.Degradation data in different tunneling length are assumed to obey Normal distribution or Weibull distribution(distribution parameters are associated with tunneling length "x"),and these distribution parameters,(?)(x)and (?)(x),or (?)(x)and (?)(x),are calculated on the basis of the degradation data investigated in working field,then the equations between distribution parameters and tunneling length "x" are available by data matching or fitting.Thus,the assessing model of reliability can be settled,and the reliability corresponding to different tunneling length can be calculated,also the figure describing reliability and tunneling length can be drawn;4.Based on degrading curves form multiple samples,the prediction of these curves can be reached from the fitting equations,therefore the tunneling length "x" that corresponding to degradation threshold "Df" can be obtained,in the end,residual service life with a certain confidence could be also calculated by probability and statistics working;...