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The following structural characteristics should be taken into account when selecting steel products

News introduction

  1.TypesandImportanceofStructures


  Becauseofthedifferenceofusingconditionandstructurelocation,thestructurecanbedividedintothreecategories:important,generalandsecondary.Forexample,large-spancivilrooftrusses,heavydutycranebeams,etc.areimportant;therooftrussesandcolumnsofordinaryfactorybuildingsaregeneral;ladders,railings,platformsandsoonaresecondary,andsteelgradesshouldbeselecteddifferentlyaccordingtodifferentsituations.


  2.TheNatureofLoad


  Accordingtothenatureoftheload,thestructurecanbedividedintostaticloadanddynamicload.Instructuresorcomponentsunderdynamicloads,therearedifferencesbetweenfullloadsandnotfullloads.Therefore,differentgradesshouldbechosenfordifferentloads.Forexample,forheavydutycranebeams,steelwithgoodimpacttoughnessandfatigueproperties,suchasQ345CorQ235C,shouldbeselected.Q235BFcanbeusedforstructuresorcomponentsunderstaticloads,suchasordinaryweldedrooftrussesandcolumns(atroomtemperature).


  3.ConnectionMethod


  Differentconnectingmethodshavedifferentrequirementsforsteelquality.Forexample,weldedsteelwillinevitablyproduceweldingstress,weldingdeformationandweldingdefectsintheprocessofwelding.Underthecircumstancesofchangingmechanicalpropertiesandtemperature,itiseasytocausenotchsensitivity,whichwillleadtocracksincomponentsandevenbrittlefracture.Therefore,weldedsteelstructureissensitivetothechemicalcompositionofsteel.Bothmechanicalpropertiesandweldabilityhavehighrequirements.Forexample,thecontentofcarbon,sulfurandphosphorusinsteelshouldbelow,theplasticityandtoughnessindexshouldbehigh,andtheweldabilityshouldbegood.However,theserequirementscanberelaxedfornon-weldedstructures,suchasthoseconnectedwithhigh-strengthbolts.


  (2)BasicRequirementsforMaterialSelectionofHigh-riseSteelStructures


  1.Thesteelgrades,steelgrades,strengthdesignvalues,selectionprinciples,mechanicalpropertiesandchemicalcompositionlimitsofthesteelsusedinhigh-risesteelstructures,aswellastherequirementsofweldingmaterialsandboltfastenersforjoints,arebasicallybondedwithgeneralsteelsexceptthatthecoldbendingpropertiesofsteelsaretakenasthebasicguaranteeconditions.Withthesamestructure,thestrengthdesignvalueofthickplatesteelshouldbecarriedoutinaccordancewiththe"CodeforDesignandConstructionofSteelStructuresforHigh-riseBuildings".Inaddition,Q235Agradeordinarycarbonstructuralsteelshouldonlybeusedassecondarynon-weldedmembers.


  2.Thesteelperformanceofthesteelstructureofthehigh-risebuildingshouldalsomeetthefollowingrequirements:


  (1)Theyield-strengthratioofsteelisnotlessthan1.2,andtheseismicfortificationstructureof8degreeandaboveisnotlessthan1.5;


  (2)Obviousyieldsteps,elongationgreaterthan20%,andgoodweldabilitytomaintainductility;


  (3)Thesteelyieldpointofsteelstructureofhigh-risebuildingsofClassAandBshouldnotexceed10%ofitsstandardvalue.


  3.Whentheload-bearingstructureisexposedandinlowtemperatureenvironment,therequirementsofatmosphericcorrosionresistanceandlowtemperaturecoldbrittlenessavoidanceshouldalsobeconsidered.


  4.Intherangeofbeam-columnjointswithweldedjoints,whenthejointisrestrainedstrongly,thethicknessoftheplateisgreaterthan50mm,andthetensionalongthedirectionofthethicknessoftheplateisapplied,theelongationinthedirectionofthethicknessoftheplateshouldbeguaranteed(morethan20%-25%)topreventthelayertearing.


  5.Inthesamehigh-risestructure,differentsteelgradesandstrengthgradescanbeselectedaccordingtothepositionofmembersandthedifferentstressconditions.


  6.Q235steelissuitableforprofiledsteelsheetsusedinenclosurestructuresandcompositeplates.


  7.Thematerialofshearboltandweldingnailusedinhigh-risesteelstructure,suchasnailrodmagneticring,shouldmeettherequirementsofrelevantstandards.Specialweldingequipmentshouldbeusedtoensureitsshearbearingcapacity.


  8.Theconcretelabel,steelbaranditsdesignstrength,andlightweightaggregateconcretematerialsusedincompositeslabsandcomponentsofhigh-risesteelstructuresshouldmeettherequirementsofthecurrentnationalstandards.