简介：TheshearlagtheoryisusedtoanalyzethestresstransferfromconcretematrixtoFBGsensorsbasedonthattheFBGsensorandtheconcretematrixarecomposite.Thestresstransferformulaandthecoefficientareobtained.Theexperimentsprovethatthetheoreticalresultsofthestresstransferbythestresstransferformulaareinwellagreementwiththeexperimentaldata.

简介：ThediamondfilmsadherenttoSisubstratearedepositedwiththemicrowaveplasmaCVD(MPCVD)atmicrowavepowersof6000Wand4000Wfrom6hto10h,respectively,theinternalstressesofthefilmsaremeasuredbyXRD.Spectralpeakshiftandwideningareappliedtocalculatethemagnitudesofmacroandmicrostresses.Theresultsshowthatthemacrostressistensile.Theinternalstresscanbecontrolledbythemicrowavepower.Withthemicrowavepowerincreasing,theintrinsicandmacrostressesdecrease,andthemicrostressincreasessignificantly.Also,itcanbefoundthatthemacroandmicrostressesincreasewithdepositedtimewhentheotherconditionsarethesame.

简介：UnderType-IIprogressivelyhybridcensoring,thispaperdiscussesstatisticalinferenceandoptimaldesignonstepstresspartiallyacceleratedlifetestforhybridsysteminpresenceofmaskeddata.ItisassumedthatthelifetimeofthecomponentinhybridsystemsfollowsindependentandidenticalmodifiedWeibulldistributions.Themaximumlikelihoodestimations(MLEs)oftheunknownparameters,accelerationfactorandreliabilityindexesarederivedbyusingtheNewton-Raphsonalgorithm.Theasymptoticvariance-covariancematrixandtheapproximateconfidenceintervalsareobtainedbasedonnormalapproximationtotheasymptoticdistributionofMLEsofmodelparameters.Moreover,twobootstrapconfidenceintervalsareconstructedbyusingtheparametricbootstrapmethod.TheoptimaltimeofchangingstresslevelsisdeterminedunderD-optimalityandA-optimalitycriteria.Finally,theMonteCarlosimulationstudyiscarriedouttoillustratetheproposedprocedures.

简介：ThestainlessFe-Mn-Sishapememoryalloy(SMA)coatingwaspreparedonthesurfaceofAISI304stainlesssteel.Theprincipalresidualstressmeasuredbythemechanicalhole-drillingmethodindicatesthattheFe-Mn-SiSMAcladdingspecimenpossessesalowerresidualstresscomparedwiththe304stainlesssteelcladdingspecimen.Themeanstressvaluesoftheformerandthelatteron10-mm-thicksubstrateare4.751MPaand7.399MPa,respectively.What’smore,theirdeformationvalueson2-mm-thicksubstrateareabout0°and15°,respectively.Meanwhile,thevariationtrendandthevalueoftheresidualstresssimulatedbytheANSYSfiniteelementsoftwareconsistwithexperimentalresults.TheX-raydiffraction(XRD)patternshowsε-martensiteexistsinFe-Mn-SiSMAcoating,whichverifiesthemechanismoflowresidualstress.That’stheγ→εmartensitephasetransformation,whichrelaxestheresidualstressofthespecimenandreducesitsdeformationinthelasercladdingprocessing.