honeycomb structures (guided inquiry)

Page|14 HoneycombStructures(GuidedInquiry)–RemSTEP(DeakinUniversity)

L A B O R A T O R Y L E A R N I N G A C T I V I T Y

HoneycombStructures(GuidedInquiry)

IntroductionAcommonaimofmaterialsscientistsandengineersistocreatematerialswiththegreateststrengthandtheminimumweightandminimumamountofmaterials(minimumcost).Honeycombsandwichstructuresareoftenusedtoachievetheseoutcomesandareusedinaerospace,automotive,housing,packaging,sports-equipmentandotherindustries.Thesestructureshaveanarrangementoftubes(orchannels)sandwichedbetweentwowalls.

Glassaluminumreinforced(GLARE)honeycombcompositesandwich

structure.Photographhasbeenusedandredistributedunderaneducationalnon-

commerciallicencebypermissionofNASA.<https://commons.wikimedia.org/wiki/File:Glare_honeycomb.jpg>

Cardboardisoftenmadebysandwichingasheetofcorrugatedcardboardbetweentwosheetsofthickpaper.Incorrugatedcardboard,theopensectionsrunparalleltothewalls.


Forcesappliedatrightanglestothehoneycombchannelswillcausethestructure

todeform.

Diagramofcorrugatedcardboard.

DiagrambyKieranFLim.

Insomeotherstructurestheopentubesarearrangedatrightanglestothewalls.Thesetubescanbedifferentshapesincrosssection.Theycouldbecircles,squares,trianglesorhexagons(likehoneycomb).

Honeycombpatternforstrengthincardboard.Imageby

sciencestockphotos.com.<http://sciencestockphotos.com/free/engineering/slides/cardboard_str

ength.html>

KeyideasForce-Aforceisapushorapull.Aforcecancausemovementinanobjectorcausecompression,tensionortorsionwithintheobject.

Impact-Impactorimpactforceisashockorlargeforceappliedforaveryshorttime.

Compressionforce–apushthatsqueezesanobjecttotrytomakeitsmallerorshorter.


Tensionforce–apullstretchesanobjecttotrytomakeitbiggerorlonger.

Strength–Theabilityofamaterialtoresistbreakingwhenaforceisapplied.

Strengthtomassratio-Thisisameasureofthestrengthofamaterialcomparedtoitsmass.

Investigation-Ascientificprocessofansweringaquestion,exploringanideaorsolvingaproblemthatrequiresactivitiessuchasplanningacourseofaction,collectingdata,interpretingdata,reachingaconclusionandcommunicatingtheseactivities

Variable-Somethingthatcanchange.

Dependentvariable-Variablethatchangesinresponsetochangesintheindependentvariableandthatisobservedormeasured.

Independentvariable-Variablethatisdeliberatelychanged.

Controlledvariables-Variablesthatarekeptconstant.

Fairtest-Whentestingdifferentmaterialsallthevariablesexcepttheonebeingtestedneedtobekeptthesame.

Equipmentandmaterials• Kirigamihoneycombtemplate• Paper,cardboard,straws• Scissors• Craftknives• Glue• Rulers• Pencils• Weights,bricks

InvestigationInthisactivity,yourtaskistochooseaquestionaboutthestrengthofhoneycombstructuresandthenyouwillformulateahypothesisbasedonscientificknowledge.Onceyouhaveyourquestionyouneedtodesignawaytoansweritbyconstructingthedifferenthoneycomb


structuresoutofpaper,cardboardandglueandtestingtheirstrength.Youwillensurethatyourtestswillbefairandprovidedatarelevanttoansweringyourquestion.Youwillcollect,analyseandevaluatethedatacommunicatingyourfindingsappropriately.

HazardsCuttingmaterialswithscissorsorbladesposestheriskofcuts.Careshouldbetakentokeephandsandfingersoutoftheway.Alwayscutwayfromyourself.Makesuresharpobjectsarestoredsafelywhentheyarenotbeingused.

Testingthesandwichmaterialswithloadshaspotentialforinjury.Caremustbetaken.Ensureallpeopleareatasafedistance.

KirigamihexagonalhoneycombstructureTheJapaneseartofkirigamiinvolvesbothcuttingandfoldingsheetsofpapertoobtainthree-dimensionalshapes.Recently,scientistsusedkirigamitocreateshape-shiftingmaterials,whichcouldhavelargeshapeandvolumechangesandwithextremelydirectional,tuneablemechanicalproperties[Footnote4].

Templateforkirigamihexagonalhoneycombstructure.


4 Neville,R.M.,Scarpa,F.,&Pirrera,A.(2016).ShapemorphingKirigamimechanicalmetamaterials.ScientificReports,6,Articlenumber31067.doi:10.1038/srep31067.Retrieved10October2017from<https://www.nature.com/articles/srep31067>.


UsinganA3-sizedversionoftheKirigamihoneycombtemplate,constructahoneycombstructure.First,foldalongthedottedlinestomaketwofoldsup,twofoldsdown,andrepeatingthispattern.


Nextcutalongthesolidlines.Thenfoldinaconcertinapatternalongthelinesofthecuts.

Thekirigamihexagonalhoneycombstructure.DetailfromFigure2of

Neville,Scarpa,andPirrera(2016).FigureusedunderaCreativeCommons(CCBY4.0)licence.

<https://www.nature.com/articles/srep31067>

Finally,glue(orstaple)theflapstogethertoformahexagonalhoneycombstructure.


Ahexagonalhoneycombstructure.Imagebysciencestockphotos.com.<http://sciencestockphotos.com/free/engineering/slides/cardboard_str

ength.html>

Makeapredictionoftheloadthatcanbesupportedbythegluedkirigamihoneycombstructure.

Weighabookorothersolidflatobjectandplacethatonthegluedkirigamihoneycombstructure.Addweightstothebookorothersolidflatobjectuntilthestructurecollapses.Whatwasthetotalmassontheload?Isthiswhatyouexpected?


ScientificquestionTherearemanyscientificquestionsthatcouldbeaskedabouthoneycombstructures.

• Howdoesthestrengthofthehoneycombstructuredependonthenumberoftubesoropenchannels?

• Doesthestrengthofthehoneycombstructuredependonthehexagonalcross-sectionalshapeofthetubesoropenchannels?Whatifthetubesoropenchannelsweretriangular,orsquareorcircular?

• Whatwouldhappenifwehadseparatetubes,butnotconnectedorgluedtoeachother?


• Doesthestrengthofthehoneycombstructuredependonwhetherthetubesaregluedorjoinedtogether?

Whatloadcanbesupportedbyanumberofjoinedidentical

“tubes”?DiagrambyKieranFLim.


Yourteacherwillleadadiscussiontodecidewhichscientificquestionswillbeinvestigated.Yourgroupwillthendecidehowtoinvestigatethatquestion.

Thescientificquestionthatmygroupwillinvestigateis:

Ahypothesisisatestable“educated-guess”answertoascientificquestion.Ahypothesisleadstooneormorepredictionsthatcanbetestedbyaninvestigation.

Ourhypothesisis:

Remembertothinkaboutvariablesthatwillneedtobecontrolledtoensurea“fairtest”.Decidewhichvariablesyouwillkeepthesame(controlledvariables)whichvariableyouwillchange(independentvariable)andwhichvariableyouwillmeasure(dependentvariable).

Ourindependentvariableis:


Ourdependentvariableis:

Ourcontrolledvariablesare:


Wewillusethefollowingexperimentalprocedure.(Ifappropriate,makeadrawingofyourproposal.)

Arethereanysafetyissuestoconsider?


ResultsWhathappened?Recordyourobservationsormeasurements.(Hint:putallthedataonasinglegraph.)


DiscussionWhattrend(s)canbeobservedinyourdata?(Hint:Useappropriatescientificlanguageandrepresentations.)


Drawapicturerepresentingwhathappenswhenloadisplacedonasinglehoneycombtubeorchannel.

Drawapicturerepresentingwhathappenswhenloadisplacedonasetoflinkedhoneycombtubesorchannels.


ExtensionConstructahoneycombstructureusingcoffeecups[Footnote5].Gaffertapeshouldbeusedtostickthetopsofthecupstogether(lengthwise)andcontinuearoundthebottomsofthecups(alsolengthwise).Alsousegaffertapetomakesomecrosswisebindings.

Coffeecup-honeycombsandwichstructure.

Photographbybertus52x11,andusedunderaCreativeCommonsGeneric(CCBY-NC-SA2.5)licence.

<http://www.instructables.com/id/Coffee-Cup-Honeycomb-Sandwich-Structure/>

Makeapredictionoftheloadthatcanbesupportedbythecoffeecuphoneycombstructure.

5 bertus52x11(n.d.).Coffeecup-honeycombsandwichstructure.Retrieved10October2017from<http://www.instructables.com/id/Coffee-Cup-Honeycomb-Sandwich-Structure/>.


Testthemaximumloadthatcanbesupportedbythecoffeecuphoneycombstructure.Whatwasthetotalmassontheload?Isthiswhatyouexpected?

ConclusionWhatconclusionscanbesupportedbyyourdataandotherthoughtsandobservations?

AcknowledgementsThecontributionsofmembersofScoutsVictoriatotherefinementofthislaboratorylearningactivityaregratefullyacknowledged.

• PhotographofahoneycombpatternforstrengthincardboardhasbeenusedandredistributedunderaCreativeCommons(CCBY4.0)licence<sciencestockphotos.com/imagelicense.html>.


• FiguresfromNeville,Scarpa,&Pirrera(2016)“ShapemorphingKirigamimechanicalmetamaterials”havebeenusedandredistributedunderaCreativeCommons(CCBY4.0)licence<https://creativecommons.org/licenses/by/4.0/>.

• PhotographofacoffeecuphoneycombsandwichstructurehasbeenusedandredistributedunderaCreativeCommons(CCBY-NC-SA2.5)licence<https://creativecommons.org/licenses/by-nc-sa/2.5/>.

• PhotographofGlassAluminumReinforced(GLARE)honeycombcompositesandwichstructurehasbeenusedandredistributedunderaneducationalnon-commerciallicencebypermissionofNASA<https://www.nasa.gov/multimedia/guidelines/index.html>.

CopyrightandCreativeCommonsExceptinglogos,trademarksorotherthird-partycontentasindicated,thisresourceisdistributedunderaCreativeCommons‘Attribution-NonCommercial-ShareAlike’4.0InternationalLicense.Themoralrightsoftheauthors,KieranLim,StuartPalmer,IanBentley,PetaWhite,JohnLong,RussellTytler,andMaryVamvakas,havebeenassertedundertheAustralianCopyrightAct1968(Cth).

honeycomb structures (guided inquiry)

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