Thetowerofthewind turbineinstallationthe use ofhydraulictorque wrenchforgedflange boltsfastening.Itsmajorshortcomings:Bolttorsionalthecompositeforceso theboltstrengthrequiredreduction,thediscrete natureofthetorquecoefficientcaused bytheboltpre-tensionis difficult to accuratelyapplied,hydraulictorquewrenchsizedeterminesboltstobefarawayfromthecylinder wallresulting intheflangematerialamount oftheincrease. Thepre-tensionisappliedtothehigh-strength boltsusinga torque wrenchisapplyingpre-tensionboltsindirectmethod.Thedesign of steel structures(GB50017-2003) "theprovisionsofArticle 7.2.2DescriptionPre-Rally.Where1.2groundspull,shear(torquecaused by)thecompositestress-inducedstrength reduction;bolt strengthtensilestrengthprevail,the introduction ofadditionalsafety factorof0.9.This shows thatthetorqueappliedtotheboltpre-tensionthe boltstrengthdecreases. "SteelConstruction Quality Acceptanceprovideshigh strength bolts connectingtheviceend ofscrewtorque values.Bolt Nominal Diameterstandard valuefor the construction ofpre-tensionvaluesforthetorquecoefficient,for thefinalscrewtorque values.Theaveragetorque coefficientis 0.110to0.150,andthestandard deviationislessthanorequal to0.010.Constructionacceptance ofthetorque coefficientrelative error ofabout± 15%.Theerrorofthetorquecoefficientboltpre-tensionmustexista certain degree oferror.Inaddition,thehigh-strength boltsmust betimelydeterminationtorque coefficientfailedtorque coefficientcan not be usedmore than six monthsneedtoretest.Themeasured torquecoefficienttakesa feeandmayresultinboltscrappeddue tothetorque coefficientsingleunqualified.Visibleusingtraditionalfastening bolttorque method,thereisacertainlack of. Hydraulictwin-cylinderhigh-strength boltsthetensioncan be directlyappliedtotheboltpre-tensionthebuttnut(setspulledtheboltsat the top ofone end of theother end of thedouble-headedscrewendsets intension),through the oil pumpon thetensionis pressurized,in order to achievethe purposeofthetensioningbolt.Usingtwo-cylindertensioncan be reducedtothesizeofthetension,thetensionandtheboltcloser tothecylinder wall.
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