ComparisonsonAPIRP2A WSD21st edition

2000Publicationvs.2007Publication

StrengthofTubularJoints

6/24/2010 1EngineeringDynamics,Inc

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OverviewTheold(wewillcallitAPI2000):

APIRP2A WSD21st edition2000Publication

Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms Working Stress Design

Upstream Segment

API RECOMMENDED PRACTICE 2A-WSD (RP 2A-WSD)

TWENTY-FIRST EDITION, DECEMEBER 2000

Andthelatest(wewillcallitAPI2007):

APIRP2A WSD21st edition2007Publication(API2007)

Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms Working Stress Design

Upstream Segment

API RECOMMENDED PRACTICE 2A-WSD (RP 2A-WSD)TWENTY-FIRST EDITION, DECEMEBER 2000ERRATA AND SUPPLEMENT 1, DECEMBER 2002ERRATA AND SUPPLEMENT 2, SEMPTEMBER 2005ERRATA AND SUPPLEMENT 3, AUGUST 2007

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Conclusions1. Thelatest.ThenewAPIRP2A WSD21st editionwithErrataand

Supplement1,2an3hasmadewiderangingchangesontubularconnections,fatigueandfoundationsoverthe2000publication.ThenewcodeshouldbeusediftheAPIRP2A WSD21st editionisselectedasdesigncode.

2. Onestopsolution,nointerfacehandling.Basedon35+yearsexperienceinsupplyingoffshorestructuresoftwaresystem,EDIistheleadingsoftwarecompanywithintegratedgraphicsmodeling,preprocessing,solvingandgraphicspostprocessingcapabilities.

3. Demandthebest.Fullyimplementedinpostprocessor,jointcanandfatigueprogramsinSACS5.3release,thenewAPIRP2A WSD21st editionwithErrataandSupplement1,2and3isnowanessentialpartinthe mostcomprehensiveoffshorepackageintheworld.

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StrengthofTubularJointsCodeContents

API20004 Connections4.1 Connections of Tension and Compression

Members4.2 Restraint and Shrinkage4.3 Tubular Joints

API20074 Strength of Tubular Joints4.1 Application4.2 Design Considerations4.3 Simple Joints4.4 Overlapping Joints4.5 Grouted Joints4.6 Internally Ring-stiffened Joints4.7 Cast Joints4.8 Other Circular Joint Types4.9 Damaged Joints4.10 Non-circular Joints

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Fact:

Lastmajorupdatetojointstrengthprovisionswas14th edition.Theguidanceessentiallyremainedunchangedforalleditionsupto21st.

StrengthofTubularJointsBackground

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Fact:Muchfurtherknowledge,includingbothexperimentaldataandnumericalstudies,hasbeengainedonthebehaviorofjointssince14th editionissued.Overtheperiod1994to1996MSLengineering,undertheauspicesofajointindustryproject,undertookanupdatetothetubularjointdatabaseandguidance.Thisworkhadmorerecentstudies,notablybyAPI/EWIandtheUniversityofIllinois,haveformedthebasisofthetubularjointstrengthprovisionsofISO.

StrengthofTubularJointsBackground

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Fact:

TheISOdraftingcommitteetook,asastartingpointfordrafting,therelevantprovisionsfromAPIRP2ALRFD1st edition(similartoAPIRP2AWSD20th edition)becauseISOisinLRFDformat.Forthepurposeofthesupplementtothe21st

editionofAPIRP2A,thedraftISOprovisions,inturn,havebeenusedasastartingbasis.

StrengthofTubularJointsBackground

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StrengthofTubularJointsMajorUpdate

API2007

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Minimum Capacity Check Revised

API2000

InwhichPaiscalculatedasfollowswithFS=1.0

InSACSprogramthefollowingequationisused:

API2000

SF=1.7CorrespondedtoanLRFDresistancefactorof0.95.

StrengthofTubularJointsMajorUpdate

SafetyFactorRecalibrated

API2007

SF=1.6CorrespondedtoanLRFDresistancefactorof1.0

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API2000

Section4.1

Fyc theyieldstrengthofthechordmemberatthejoint(or2/3ofthetensilestrengthifless)

StrengthofTubularJointsMajorUpdate

The2/3limitsontensilestrengthrelaxed

API2007

Section4.2.1

Thevalueofyieldstressforthechord,inthecalculationofjointcapacity,shouldbelimitedto0.8timesthetensilestrengthofthechord formaterialswithayieldstressof72ksi(500MPa)orless.

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API2000

StrengthofTubularJointsMajorUpdate

Additionalguidanceondetailingpractice

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StrengthofTubularJointsMajorUpdate

Additionalguidanceondetailingpractice continued

API20076/24/2010 12EngineeringDynamics,Inc

API2000Theadequacyofthejointmaybe

determinedonthebasisof(a)punchingshearor(b)nominalloadsinthebrace.

StrengthofTubularJointsMajorUpdate

Punchingshearapproachremoved

API2007Thejointinteractionratio,IR,foraxial

loadsand/orbendingmomentsinthebraceshouldbecalculatedusingthefollowingexpression,

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API2000

StrengthofTubularJointsMajorUpdate

NewStrengthfactorQu formulations

API2007

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API2000

StrengthofTubularJointsMajorUpdate

NewchordloadfactorQf formulations

API2007

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API2000N/A

StrengthofTubularJointsMajorUpdate

StrengthforaxiallyloadedYandXjointswithshortcanlengthsreduced

API2007Forsimple,axiallyloadedYandXjointswherea

thickenedjointcanisspecified,thejointallowablecapacitymaybecalculatedasfollows,

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API2000

Fullyimplemented

StrengthofTubularJointsMajorUpdate

ImplementationintoSACSjointcanprogram

API2007

Fullyimplemented

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SimpleTjoint:

Brace34:16x0.375 5.0ft

Chord13&32:24x0.375 8.25ft

Can:24x0.625 1.75ft

AllFy =36ksi

Loadatbracejoint4:Fx=10.0kip

Fy=7.5kip

Fz=50.0kip

Loadatconnectingjoint3:

Fx=400.0kip

Fy=50.0kip

StrengthofTubularJointsExample

MemberLengthshowninft

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API2000 Punchingshearjointcheckwithfinalunitycheckratio=0.974

* * J O I N T C A N D E T A I L R E P O R T * *(JOINT ORDER)

CHORD * ACTING STRESSES * *** PUNCHING SHEAR ***COMMON CHORD BRACE ****** CHORD ***** JOINT GAP *** BRACE ** BRACE LOAD *CHORD** BRACE * ALLOWABLE STRESSES UNITYJOINT JOINT JOINT O.D. WT FY TYPE O.D. WT ANGLE CASE SRSS FA OPB IPB FA OPB IPB CHECK

(IN) (IN) (KSI) (IN) (IN) (IN) (DEG) (KSI) (KSI) (KSI) (KSI) (KSI) (KSI) (KSI)3 1 4 24.00 0.625 36.0 T 16.00 0.375 90.00 1 11.51 -1.63 3.84 5.12 3.66 6.65 11.15 0.974

StrengthofTubularJointsExampleResultsCompared

API2007 Braceloadsinteractioncheckwithfinalunitycheckratio=1.168

* * J O I N T C A N D E T A I L R E P O R T * *(UNITY CHECK ORDER)

EFFT. CHORD * ACTING STRESSES * *** PUNCHING SHEAR ***COMM CHRD BRCE ****** CHORD **** CHORD JNT GAP *** BRACE ** BRACE LOAD *CHORD** BRACE * ALLOWABLE STRESSES UNITYJNT JNT JNT O.D. WT FY LNGTH TYP O.D. WT ANGLE CASE STRESS FA OPB IPB FA OPB IPB CHECK

IN IN KSI FT IN IN IN DEG KSI KSI KSI KSI KSI KSI KSI 3 1 4 24.00 0.625 36.0 3.5 T 16.00 0.375 90.00 1 -11.51 -2.72 6.40 8.54 7.20 10.16 21.30 1.168

JointCanLength

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