请教关于MTBF的问题
我想通过实验计算某电子产品的MTBF值,请问需要进行什么实验?实验应遵循哪些标准?请各位高手帮忙回答,或推荐一些资料,小弟刚接触可靠性,很多不懂,谢谢!!:P 規范你可以參考MIL-HDBK-217或 Telcordia 我们公司测试MTBF是在温度:40度,湿度:85%的环境下加温,根据该环境与用户使用环境的差异算出加速因子,在去算MTBF 原帖由苏州检测机构于2008-8-1114:21发表这个问题很简单,我们是专门做检测的,需要资料的话给我电话或者邮件13771850837wapp10000@126.com
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如果楼上朋友觉得问题很简单,可以发表你的观点。 还是不太清楚,希望有高手细心解答,呵呵! ReliabilityDemonstrationMethods
Whendemonstratingthereliabilityofaproduct,theexactfailuretimecanneverbeknow.Notwithstandingthisfact,wearerequiredtohypothesizeregardingourconfidenceintheintegrityofournumbers.TheChi2distributionisoftenusedinthiscasebecauseitisaprobabilitydistributionthatrelatestheobservedtotheexpectedvalues.
TherelationshipbetweenfailurerateandtheChi2distributionisasfollows:
lamda=X^2(Alpha,Bate)/2*time*Af
Where
alpha=((100–CL)/100CL(ConfidenceLevel)=60%,90%.
Bate=Degreesoffreedom=2*numberoffailures+2
Af=Accelerationfactor,asdeterminedbyoneofthemethodsdiscussedearlier
Whenestimatingfailurerates,Vicorusesaccelerationfactorstodetermineusefailure
ratesbasedonlabfailurerates.
AcceleratedLifeTesting
Theequationbelowisusedtomodelaccelerationduetotemperatureandisreferredtoas
theArrheniusequation.TheArrheniusequationrelateshowincreasedtemperature
acceleratestheageofaproductascomparedtoitsnormaloperatingtemperature.
Af=e^{(Ea/k)*(1/Tu-1/Tt)}
Af=accelerationfactor
Ea=activationenergyinelectron-volts(eV)
k=Boltzmann’sconstant(k=8.617x10-5eV/Tk)
Tk=Kelvin
Tu=referencejunctiontemperature,indegreesKelvin(K=C+273)
Tt=junctiontemperatureduringtest,indegreesKelvin
e=2.71828(baseofthenaturallogarithms)
MTBF=1/lamda 規范你可以參考MIL-HDBK-217或 Telcordia 規范你可以參考MIL-HDBK-217或 Telcordia
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