Author/Authors :
Hyo-GyoungKwak، نويسنده , , JaeHongKim، نويسنده ,
Abstract :
Twomodifiedstress–strainrelationsforbondedandunbondedinternaltendonsareproposed.Theproposedrelationscansimulatethepost-crackingbehaviorandtensionstiffeningeffectinprestressedconcretecontainmentstructures.Inthecaseofthebondedtendon,tensileforcesbetweenadjacentcracksaretransmittedfromabondedtendontoconcretebybondforces.Therefore,theconstitutivelawofabondedtendonstiffenedbygroutneedstobedeterminedfromthebond–sliprelationship.Ontheotherhand,astressincreasebeyondtheeffectiveprestressinanunbondedtendonisnotsection-dependentbutmember-dependent.Itmeansthatthetendonstressunequivocallyrepresentsauniformdistributionalongthelengthwhenthefrictionlossisexcluded.Thus,usingastrainreductionfactor,themodifiedstress–straincurveofanunbondedtendonisderivedbysuccessiveiterations.Inadvance,thepredictionofcrackingbehaviorandultimateresistingcapacityofprestressedconcretecontainmentstructuresusingtheintroducednumericalmodelsaresucceeded,andtheneedfortheconsiderationofmanyinfluencingfactorssuchasthetensionstiffeningeffect,plastichingelengthandmodificationofstress–strainrelationoftendonisemphasized.Finally,thedevelopednumericalmodelsareappliedtoprestressedconcretecontainmentstructurestoverifytheefficiencyandapplicabilityinsimulatingthestructuralbehaviorwithbondedand/orunbondedtendons.
