简介：Toestimatethelifetimeofpneumaticcylinderinmachinetool(orautomaticassemblyline),newreliabilitymethodologyforparametricacceleratedlifetesting(ALT)issuggested.ItconsistsofparametricALTplan,generalizedlife-stressfailuremodelwithaneweffortconcept,accelerationfactor,andsamplesizeequation.ThisnewparametricALTenablesanengineertoestimatethelifetimeofacommerciallypartsbyuncoveringthefailurethroughacceleratedtestingundersevereconditions.Asacasestudy,twocommercialproductsofthepneumaticcylinderinmachinetoolweretested.ForcompanyA,wefoundthehardeningandwearofpistonseallikethatoffieldatnormalconditions.Asincreasingthepressure,thepneumaticcylindersweretested.Basedontheacceleratedconditions—0.8MPaand1.2MPaat23℃,B1lifeat0.63MPaand23℃wasextrapolatedas2.39×10^6.Ontheotherhand,forcompanyB,wefoundtherodcapblockedbyslurrylikethoseoffieldsamples.Basedontheacceleratedconditions—0.8MPaand1.4MPaat23℃,B1lifeat0.63MPaand23℃wasextrapolatedas2.51×10^6.Comparingthemwithtestingdataatnormaluseconditions,weknewthattheestimationerrorforbothcompanieswaslessthan10%.