Transcription of 3 DESIGN CONSIDERATIONS FOR ALUMINUM HULL …
1 / 3 DESIGNCONSIDERATIONSFORALUMINUMHULLSTRUC TURESS~UDYOFALUMINUMBULKCARRIERT hisdocumenthasbeenapprovedforpublicrelea seandsale;itsdistributionsunlimited.,,-. , > <. ,-1971- w.,..- , ,..;. ,. ,IIIRearAdmiral, ,ShipStructureCommittee,..-!,,.,1- .. ,..-..- ,..- .._SSC-218 FinalTechnicalReportProjectSR-190 Alumin;~HullFeasibilityStudy ;itsdikkibutioni; , ,thoughadditionalresearchisrequired, , , sstructureweighs43percentlessthanthestee lship, sindicatethatforthesamereturnoninvestmen ttherequiredfreightrateofthealuminumbulk carrierishigherthantheequivalentsteelshi p,foralllevelsofprocurement,assumedhulll ife, ,.. ,.. ,.. *.. !37109111115121124127,.. ~. (5086-H34)..29 CorrosionResistanceofAluminumAlloystoTid eRangeSeaWaterImmersion-SevenYears ,LiningsandInsulationinLiving, ,InsulationandDeckCoveringinLiving, ( ).
2 77!laterialCost-BilgeSysteminBallastTank s( ).. ~ (Cent d) (HomogeneousCargo).. (Ck,a2 ZwzgerClass) ,..100 ComparisonofSteelandAluminumBulkCarriers (OzzZZengerClass) (ClzaZZengerClass) . - .. c ..50 SternTube& .. (Cent d) **LongTermDistributionofVerticalBendingM oment(ForPreliminaryDesign).. , ,III,USCG,ChairmanChief,OfficeofMerchant MarineSafetyU, ,USNt!;!e:. , , ,VicePresidentMilitary,SealiftCommandAme ricanBureauofShippingSHIPSTRUCTURESUBCOM MITTEETheSHIPSTRUCTURESUBCOMMITTEE actsfortheShipStructureCommitteeontechni calmattersbyprovidingtechnicalcoordinati onforthedeterminationofgoalsandobjective softheprogram,andbyevaluatingandinterpre tingtheresultsintermsofshipstructuraldes ign,construction, , , , , , , , , ,LiaisonSOCIETYOFNAVALARCHITECTS& , , , ,RCNC, , , , ,offeri~ , ,sothatthetotalmaterialcostofanaluminumh ullwillbebetween2-1 ~ondoesnotgenerallyresultinasignificantr eductioninthelaborcostsforhullconstructi on.
3 OHigh-speedhullforms,particularlyplaning hulls, , ,theintroductionofaluminumalloysintothem arineindustryhasencounteredtechnicaldif- ficultiesinsomeareas,resultingfromeither thebasiccharacteristicsofaluminumalloys, ~ ~ overcome,carefulconsiderationmuststillbe giventostrengthdegradation, , ,shafting,propellers~ ,numst? , ~ ,asthetechnicalproblemshavebeenovercomea ndthestateoftheartinfabri-catingaluminum structureshasadvanced,aluminumhasbeencon sideredandusedinlargerhulk, ) , , ;INDEFENDENCE , , , ALUMINIL .o160footferryGTS TAVALONT .Amajorfactoraffectingthefutureofaluminu minmarineapplicationsistherecenttrendtow ardevaluationoflifecyclecost,inwhichallf actorsaffectingtheeconomicsofaspecificsy stemareevaluatedoverthelifetimeofthesyst emtodeterminetotalcostthroughoutitsli~ , ,inconjunctionwiththerecentadvancesinthe stateofthe-3-artinfabricatingandmaintain ingaluminum, :oMaterialandDesignStudiesincludingarevi ewofalloyproperties,developmentofcriteri a,methodsoffabrication,fireresistance, ,includingmodificationoftheselectedsteel bulkcarriertosuit1969strengthstandards,a nddesignofanequivalentaluminumbulkcarrie r.
4 Dimensions,midshipsection,weights, , ,ifany,largeoceangoinghigh-densitybulkca rriershavebeenbuiltinthiscountryinthepas t20years,thisstudyisbasedonahypothetical shipwhichisphysicallyidentical* ,sincethephysicalcharacteristicsoftheexi stingbaselineshiparewelldoc~ , -10 LengthBetweenPerpendiculars590 -6-I/2 Beam,g8I-711 Depth521-211 Draft351-911 Deadweight36, ,892 LTDisplacement44, ,6oomax.(Dl_esel) ,400statutemilesBuilt1955,MitsubishiHeav yIndustries, +AIE BulkCarrier *mStrengthenedforhea~cargoesRegistration Monrovia, ,633(Liberian)NetTonnage13,451(Liberian) +steelconstruction, :oThealuminumhullstructurewouldbeeconomi callymoreviableforasmallerbulkcarrier(30 -40,000tonsdeadweight)thanwithalargerves sel, <,, , ;---,.,,/,..< >:.,/ <-=:--- . +.~/------,--I/=.
5 /-/-,, (. ,.,,~~ ~,.!/, ) + I-. I[IIII1~.7o8 y\,1~UpperTmnavaIweStruoture, ;3;4 ~ced126fi11,//@ 94nJ,,,.,.> ~IW 1/,,y . L(TY P)\ShellXOng11+l33 Lr14*2%3, . :__r_Img!linHopperT&.nkr-t5=9%3=5 ~~ L(TYP) .433 . 1-rrr1 8@ 4----m m =:846 ~.. ~91 L(w) , ~-7-11, , ,suchas6051,haveexcellentsaltwatercorros ionresistance, ,6000seriesalloyscouldbeconsideredforcat walks, (StaticandFatigue) * *SelectionofAlloysMechanicalProperties(S taticandFati~e) ,andarehereinevaluatedquanti-tatively,wh erepossible,orqualitatively:alloytemper, materialthick-ness,weldprocedure:fillerw irealloy,typeofweld-singlevegbutt,double veebutt,fillet,etc.,weldprocess(MIG,TIG, etc.),welddefects,coldworking,surfacefin ishofparentmetalandweld,stressconcentrat ionssuchasnotches,craters,welds,etc.]
6 ,serviceenvironment, ,lowandelevatedtemperatures,compositiona ndgrainsizearediscussed,However, , (1)through(36). , ,itisrecognizedthattheyoftenrepresentrel ativetrends, , ~ertiesTable2,obtainedfromReference(l),p resentsminimum, ~ ,References(2)through(17). , ,andnodiffer-entiationismadeforfillerwir e,typeofweld,weldprocessorspecimengeomet ~ ,beadonvaluesaregreaterthanbeadoffvalues , , , ,3and4clearlyindicatesthat,forall~000ser iesalloysinvestigated, ,annealedortempered,approachesthatoftemp eredparentmaterial,duetostressconcentrat ions, ,df~,000seriesaluminumweldsareapproximat elyequaltothestaticstrengthpropertiesofa nnealed(Otemper) k,i(kg/mm @ @ @ ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) [ ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )@ @: @ @): k$i(kg/mm - ForallnumberedFootnotes,seePage13,-11-TA BLE2 Mechan calPropertiesofAluminumSheetandPlatePART ~-(cont.)]
7 KTENSILESTRENGTH ksi(kg/mmc)+ELONGATIONALLOYT hickness@) . ANDULTIMATEYIELD -in.. -m- - T- -- ( ) ( ) ( ) ( ) ( ) ( ) ( )41,0( ) ( ) ( ) ( ) ( )18 .., . ( ) .. ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )10. -.. ( ) ( ) ( ) ( ) ( ) ( )155456. ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )., ,5456-H112--. ( ) ( ) ,0( ) ( )12, ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) +o( ) --58,0(40,8) .. ( ) ( ] ( ) (40,8) ( ) ( )8,.. , (37,3) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )20 .. 5557 ~= -of ( ) (14,1) ]~20.,.. 565756~5657-H255657-H265657-H28E; ti9:o)- 22( )22( )24( )26( )28( )ENDUR-ANCE@LIMITksi(kg/mm~ 12( )13( )13( )14( )14( ]MODUWJS@OFELASTICITYIULTIMATEYIELDksi(k g/mm )x103T18( )6( )20( )19( )23( )22( )26( )25( )29( )28( )20( )17( )23( )20( )26( )24( )29( )27( )lo,oi7, ( ) ( ) ( ) ( )10,0( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) (14,8)8( )5050-H3225(17,6)21[ )5050-H3428( )24( ) ( )26( )5050-H3832( )29( )5052-028( )13( ]5052-H3233( )28( )5052-H3438( )31( )5052-H3640(28,1)35( )5052-H3842( )37( )2530121810148107816( )17( )18( )19( )20( )20( )22( )22( ) ( ) ( ) ( )5056-042( )22( )5056-H1863( )59( )5056-H3860( )50(35,2) ( ) ( )5083-0I42( )21( ) ( )33( )221623( )17( )18( )19(13,4)20( )21( )17( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )10,2( ) ( ) ( ) ( ) ( ) ( )42( )47( )39( )35( )39( )42( ))
8 45( )48( )35( )17( )30( )37( )19( ) ( )30(21,1)33( )36( )39( )17( ) ( )25( ) ,-H2841( )35(246)11521( )23( )5k57-H25I19( )16( )5257-H38,.H2823( )19( )14811( )12( ) ( ) (7,0)..,.5454-o36[ )17( )5454-H3240( )30( )5454-H3444( )35( )5454-H11138( )26( )5454-Hi1236( )18( )22101014186273817062.,..,9032485523( ).,24( ).,26( )23( ) ,23( ).,..30(21~i)12( )16( )18( )11( ).,.14[ )15( ), .. 14( )75( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) (7,2) ( ) ( ) ( ) ( )5456-O45( )23( )5456-H11147( )33( )5456-Hi1245( )24( )5456-H32151( )37( ),.241822165457-o19( )7( )5457-H2526( )23( )5457-H38,-H2830( )27( )5557-o16( )6( ) ( )20( ) , ( )24( )5657-H2523( )20( )5657-H38,-H2828( )24( )22,.126251272840504( ( ) ( ) ( ) ( ) ( )127 ForallnumberedFootnotes, (PartA-Pages9-11)Mechanicaltestspecimens aretakenasdetailedunderT%mplingandTestin g~l,pages52-54ofReference(l).]]
9 Typeoftestspecimenuseddependsonthickness ofmaterial;seeL%mplingandTestingll,pages 52-54ofReference(1).ForthecorrespofiingH 2temper,limitsformaximumultimatetensiles trengthandrninim ~ (PartB-Page12)Thesetypicalpropertiesarea verageforvariousofmanufacture,afimaynote xactlydescribeanyforms, $OO,OOO, ~ ksi(kg/mmg)TIONALLOYDISTANCEANDTEMPER .. -.. - .. ( ) ( ) ( ) ( ) ( ) ( ) ( )12 5086 ( )46,0( ) ( ) ( ) ( ) ( ) ( )12..- (21,1)41,0( ) ( )5154-H112I.,AllAll30+0( ) ( )., ( ) ( ) ( ) ( ) ( )I:;:[/4?; ( ) ( ) ( ) ( ) ( ) ( ) ( ) AverageVzlucsMatmial5052-0-H3h< ! <M-o-H3~-H111F fu252540110393535;5303041112; <182624121616 FTU(K31)ElO~abion(j) ! ~4~6-H321alloyareapproximately10percentb elowtheminimumvalue,Reference(9).Althoug hsignificant, (10)listsyieldstrengthsfor2specimensof50 86-H3~l,alloy( ) ,isabou t ~percentlessthantheminimumvalue,Figure25 ofReference(13).]
10 TiespecimenofS086-H32a~~ ,Reference(21),Th~selimitedcasesdonotmod ifytheconclusionthatthepropertiespresent edinTables2through4areconsideredsatisfac to~ , , ,testloadingprocedure,notchesandwate~ ~d(parent) (EL)arethesame,withinnormalexperimentals catter,forall~000seriesaluminumalloyseva luated, (R=-1)reducestheendurancelimitbySOpercen tfromthevalueforzerostressreversal(R=O). Theendurancelimit(EL)ofmildsteelishigher thanthatof~~ooseriesaluminumbyapproximat elythesameratioasthatfortheaveragestatic skre~~ (Otemper) ,theendurancelimitofa~ealedalloysisthesa measthatoftemperedalloys,References(4),( 5)and(7).Fatiguecurvesforbutt-weldedallo ysintheas-weldedconditionarepresentedinF igure~ ~rial,allbutt-welded~QOOseriesaluminumal loysapproachthesameendurancelimit, ,References(6)ati(16).
