简介：Thefatiguelifeofnumerousaerospace,locomotive,automotiveandbiomedicalstructuresmaygobeyond10~8cycles.Determinationoflonglifefatiguebehaviorbecomesextremelyimportantforbetterunderstandinganddesignofthecomponentsandstructures.Initially,beforetheinventionofultrasonicfatiguetesting,mostoftheengineeringmaterialsweresupposedtoexhibitfatiguelifeupto10~7cyclesorless.Thispaperreviewscurrentunderstandingofsomefundamentalaspectsonthedevelopmentofacceleratedfatiguetestingmethodanditsapplicationinultra-highcyclefatigue,crackinitiationandgrowthmechanismsofinternalfracture,S-Ndiagram,fatiguelimitandlifeprediction,etc.

简介：Particleinteractionsareofcrucialimportanceinmanyapplicationsincludingfluidizedbedsandotherpowderhandtingsystems.Thepresentcontributiondiscusseshowsurfacepropertiesoftheparticlescanbedeterminedinordertogetquantitativeinformationonparticleinteractions.Forinstance,weapplyadsorptionexperimentsinordertogetinformationondispersiveandpolarinteractions.ThesemeasurementsarecomplementedbycarefulroughnessmeasurementsasweltasFTIR-spectroscopyandTG-MSanalysis.AdhesionforcemeasurementswithAFMandultracentrifugeonwelldefinedidealaswellasheterogeneoussurfacesledtotheintroductionofthreegenerictypesofadhesionforcedistributions:monomodalWeibull.binlodalWeibullandlognormalTheinfluenceofroughnessandadsorbedlayersonadhesionareshown,Inaddition,wediscussimportantaspectsof1hedynamicnatureoftheadhesion/detachmentprocessbymeansofMD-simulations.

简介：Atheoreticalmodelthattakesintoaccountthefree-volumeaidedcooperativeshearingofsheartransformationzones(STZs)isdevelopedtoquantitativelyunderstandtheductile-to-brittletransition(DBT)ofmetallicglasses.TheSTZdilatationalstrainisdefinedastheratioofSTZ-activatedfreevolumetoSTZvolumeitself.ThemodeldemonstratesthattheSTZdilatationalstrainwillincreasedrasticallyandexceedthecharacteristicshearstrainofSTZastemperaturedecreasesbelowacriticalvalue.ThiscriticaltemperatureisingoodagreementwiththeexperimentallymeasuredDBTtemperature.OurresultssuggestthattheDBTofmetallicglassesisunderpinnedbythetransitionofatomic-clustermotionsfromSTZ-typerearrangementstodilatationalprocesses(termedtensiontransformationzones(TTZs)).