毕业论文之外文翻译.docx

毕业论文之外文翻译.docx

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毕业论文之外文翻译

Designandfabricationoflowcostfilamentwindingmachine

F.H.Abdalla,S.A.Mutasher,Y.A.Khalid,S.M.Sapuan*,

A.M.S.Hamouda,B.B.Sahari,M.M.Hamdan

B.

Abstract

Ingeneral,thecompositepipesarefabricatedusingglassfiberandpolyesterresinmatrixbyhandlay-upandalsoby2-axisfilamentwindingmachine.Inthiswork,afilamentwindingmachinewasdesignedanddevelopedforthefabricationofpipesandroundshapespecimens.Alathe-typemachineandawetwindingmethodwereusedinthedesignofthemachine.Itprovidesacapabilityforproducingpipespecimenswithaninternaldiameterupto100mmandlengthsupto1000mm.Therangeofthewindingangle,orthefiberorientationangle,startsfrom20to90dependingonthemandreldiameterused.Mandrelspeediskeptconstantas13.6revolutionsperminute（rpm）whilethespeedofscrewofdeliveryunitvariesfrom0rpmtoamaximumof250rpm.Inthefilamentwindingprocessused,asingleglassrovingisdrawnthroughabathofpre-catalyzedresinwhichismountedontheleadscrewbytherotatingmandrel.Acontrolunitwasusedtocontrolthewholeprocessandachieveregularwindingandgoodsurfacefinish.Tubesamplesandothercircularspecimensofdifferentdimensionswereproducedusingthismachineforthedifferentmechanicaltestsandapplications.

Keywords:

Filamentwinding;Compositetube;Glassfiber;Matrix;Fiberorientationangle

1.Introduction

Filamentwindinghasemergedastheprimaryprocessforcompositecylindricalstructuresfabricationatlowcost.Inthisprocess,compositelayersaresuccessivelywoundonarotatingmandrel,aspresentedinFig.1.

Thelayersmaybewrappedatdifferentanglesvaryingfromhooplayers,whichareperpendiculartothecylinderaxis,tohelicallayerswhichareatanangletothecylinderaxis.Theconstructionofcompositecylinderbyfilamentwindingconsistsofthreemajorsteps[1],thefirstisthedesign,whichincludestheselectionofmaterials,geometry,andfiberorientationswhilethesecondisfiberplacement,themechanicalmeansbywhichthefibersareplacedintheirproperpositions.Finally,thethirdistheselectionandcontrolofconditionswhichmustbemaintainedduringthe

Fig.1.Schematicofthewetfilamentwindingprocess[1].

manufacturingprocess.Aprocessforfabricatingacompositestructureinwhichcontinuousreinforcements（filament,wire,yarn,tape,orother）,eitherpreviouslyimpregnatedwithamatrixmaterialorimpregnatedduringthewinding,areplacedoverarotatingandremovableformormandrelinaprescribedwaytomeetcertainstressconditions.Thereinforcedfibersareusuallymadeofglass,Kevlarorcarbon.Owingtosimplicityofprocess,thehardwareconfigurationisquitestandard,andgenerallyinvolvestwomainsub-systems;therotaryassemblyandthedeliverysystem.Therotaryassemblyconsistsoftwostructuralblocks;onefixedandtheotherlinearlymovableunitinwhicha2-axismechanicallydrivenmandrelismountedontoitsholders.Onthefixedend,theholderisconnectedtoarotatingshaft,whichiscoupledtoeitheragearorachainorbeltreductionsystem,ordirectlytothemotorunit.Generally,anACorservo-motorisusedbecauseofitsgreatertorquecapabilitiesandaccuracywhenoperatingunderconditionsofheavyloading.Fordeliverysystem,rollsofcontinuousfibersarefedintoaresinbathwhichismountedontothecarriagerailsthatarecommonlyplacedoverheadtoprovidegreaterworkroom.Generally,theshapeisasurfaceofrevolutionandmayormaynotincludeendclosures.Whentherequirednumberoflayersisapplied,thewoundformiscuredandthemandrelremoved.Thematerialpropertiesineachlayerareconstantbutmayvaryfromlayertolayer.Themandrelisrepresentedbyahollowcylinderwithuniformeffectivewallthickness.Themandrelandthecylinderareofequallengthandareaxisymmetrical,sothatneitherthegeometrynorthepropertiesvaryinthecircumferentialdirection.Filamentwindingisdefinedas[2]atechniquewhich‘‘produceshighstrengthandlightweightproducts;consistsbasicallyoftwoingredients;namely,afilamentortapetypereinforcementandamatrixorresin’’.Theconceptoffilamentwindingprocesshadbeenintroducedinearly1940sandthefirstattemptwasmadetodevelopfilament-windingequipment.Theequipmentthatwasdesignedin1950swasverybasic;performingthesimplesttasksusingonlytwoaxesofmotion（spindlerotationandhorizontalcarriage）.Bymid-1970s,machinedesignonceagainmadeadramaticshift.Thistimetheadvancementofservotechnologyenteredtherealmofthemachinedesign.High-speedcomputersallowedforrapiddataprocessing,resultinginsmoothermotionandgreaterfiberplacementaccuracy.The1980sand1990ssawtheincreaseduseofcomputertechnology.Computersandmotioncontrolcardsbecametheessentialpiecesofhardwarethatwereincludedinalmosteverymachine.Machinespeedcontrolwasgreatlyimproved;computercontrolsystemscouldtrackpositionandvelocitywithincreasedaccuracy.Additionalaxesofmotionswerealsoincorporatedintomachinedesign;allowingforfour,fiveandevensixaxesofcontrolledmotion.

2.Manufacturingtechniques

Thepropertiesofacompositeproductarenotonlydependentonthepropertiesoffiberandresinmatrix,butarealsodependentonthewaybywhichtheyareprocessed.

Thereareavarietyofprocessingtechniquesforfabricatingcompositeparts/structure;resintransfermoulding,autoclavemoulding,pultrusionandfilamentwinding.Outoftheseprocesses,filamentwindinginvolveslowcostandisthefastesttechniqueformanufacturingoffiberreinforcedcylindricalcomponentsashigh-pressurepipesandtanks.

3.Windingmethods

Therearetwodifferentwindingmethods:

（I）wetwinding,inwhichthefibersarepassedthrougharesinbathandwoundontoarotatingmandrel（II）prepregwinding,inwhichthepreimpregnatedfibertowsareplacedontherotatingmandrel.Amongthesewindingmethods,wetwindingismorecommonandwidelyusedformanufacturingfiberreinforcedthermosettingmatrixcompositecylinders.Comparedwithprepregwinding,wetwindinghasseveraladvantages:

lowmaterialcost;shortwindingtime;andtheresinformulationwhichcanbeeasilyvariedtomeetspecificrequirements.

3.1.Windingpatterns

Infilamentwindingprocess,thewindingtensioncaneasilybecontrolled.Windingtension,windingangleand/orresincontentineachlayerofreinforcementcanbevarieduntilthedesiredthicknessandstrengthofthecompositeareachieved.Thepropertiesofthefinishedcompositecanbevariedbythetypeofwindingpatternselected.Ingeneral,therearethreebasicfilamentwindingpatternswhichareasfollows.

3.1.1.Hoopwinding

Itisknownasthegirthorcircumferentialwinding.Inhoopwinding,ahigh-anglehelicalwindingapproachesanangleof90.EachfullrotationofthemandreladvancesthebanddeliverybyonefullbandwidthasshowninFig.2.

Fig.2.Circumferentialorhoopwinding[2].

3.1.2.Helicalwinding

Inhelicalwinding,themandrelrotatesataconstantspeedwhilethefiberfeedcarriagetransversesbackandforthataspeedregulatedtogeneratethedesiredhelical

anglesasshowninFig.3.

3.1.3.Polarwinding

Inpolarwinding,thefiberpassestangentiallytothepolaropeningatoneendofthechamber,reversesdirection,andpassestangentiallytotheoppositesideofthepolaropeningattheotherend.Inotherwords,fibersarewrappedfrompoletopole,asthemandrelarmrotatesaboutthelongitudinalaxisasshowninFig.4.Itisusedtowindalmostaxialfibersondomedendtypeofpressurevessels.Onvesselswithparallelsides,asubsequentcircumferentialwindingwouldbedone.

Fig.3.Helicalwinding[2].

Fig.4.Polarwinding[2].

4.Theproposedfilamentwindingmachine

Schematiclayoutofthehardwareconfigurationforproposedfilament-windingmachineisshowninFig.5.Itconsistsofthreemainunits:

therotaryassemblyunit,thedeliveryunitandthecontrolunit

Fig.5.Schematicdiagramforproposedwindingmachine..

Fig.6.Setupofthespecimenonthewindingmachine.

4.1.Therotaryassemblyunit

Therotaryassemblyconsistsoftwopillarblockswhichwereheldontohorizontalframeworkandmotorwithagearbox.Oneofthetwoblocksisfixedandservesasareference,whiletheotheroneismovableandcanbeadjustedlinearlyforvaryingthemandrellength.Oncethemandrelisseatedproperlyintotwofreelyrotatingcupholders,themovablepillarblockisthenlocked.Atthefixedpillarend,theholderiscoupledtothemotorgearboxbyasystemofpulleysandbelt.Thegearratiobetweenthemotorandthegearboxisselectedas1:

60andthereductionratiobetweenthepulleyswastakenas1:

2,sothatthevelocityofthemandrelisfixedto13.6rpmasshowninFig.6.

4.2.Thedeliveryunit

Thedeliveryunitconsistsoffilamentfibersholder,carriageandleadscrewwithaguideshaft.Theleadscrewisdrivenbyareversiblevariablespeedmotor.Thefilamentfiberholderisjustatablewithtwoshafts,oneusedforcarryingoneormoreofthefilamentfiberrollswhiletheotheroneisusedasaguideforthefilamentfiberduringthefabricationprocess.Thecarriageconsistsofacontainerandasystemofpolishedguidepins.Thecontainerwasusedforcarryingtheresinmixturewhilethepinswereusedasawaytoguidethefibertotheresinbathandtosmearoffexcessresinfromthewettedfibersaftertheresinbath.Also,thepinswereusedtogeneratetensioninthewettedfibersbeforereachingthemandrel.Asimplemechanismwasusedtobringbackthesmearedresinfromthewettedfibertothecontainer