简介：Anappropriatecoupledcohesivelawforpredictingthemixedmodefailureisestablishedbycombiningnormalseparationandtangentialseparationofsurfacesinthecohesivezonemodel(CZM)andthecohesiveelementmethod.TheXu-Needlemanexponentialcohesivelawwiththefullyshearfailuremechanismisoneofthemostpopularmodels.Basedontheproposedconsistentlycoupledrule/principle,theXu-Needlemanlawwiththefullyshearfailuremechanismisprovedtobeanon-consistentlycoupledcohesivelawbyanalyzingthesurfaceseparationwork.ItisshownthattheXu-Needlemanlawisonlyvalidinthemixedmodefracturewhenthenormalseparationworkequalsthetangentialseparationwork.BasedontheconsistentlycoupledprincipleandthemodificationoftheXu-Needlemanlaw,aconsistentlycoupledcohesive(CCC)lawisgiven.ItisshownthattheproposedCCClawhasalreadyovercomethenon-consistencydefectoftheXu-Needlemanlawwithgreatpromiseinmixedmodeanalyses.