BUILDING CONSTRUCTION 2 (ARC 2513) PROJECT1-UNDERSTANDING FORCESINSKELETALSTRUCTURE
A REPORT BY: Alya Farina Binti Khairul Faridz Ang Yik chiu Michael Kon Keeh Yih Muhammad Zhafri Aizuddin Bin Azman Tan Wei Sheng Wan Nur Adriana Wan Roslan
0308460 0303443 0300478 0308303 0307857 0308109
INTRODUCTION TheBriefforthisprojectistoconstructatoweroutofpopsiclestickswithoutusageofglueoranyadhesivematerial.Thetower constructedhastobeabletowithstandaloadofminumum 1.25kgandwillbetestedtodeterminethemaximum loaditcanwithstandfor upto2minutesappliedatthetopofthetowerstructure.Theprojectseekstocreateanunderstandingoftheskeletalstructurein constructionandhowitreactsunderweightloading.Thisprojectalsoseekstostrengthtentheunderstandingaboutskeltalconstruction worksandthemanipulationoftheskeletalconstructiontosolveanobliquedesignproblem.
CONTENTS -
DESIGN PROCESS 1 DESIGN PROCESS 2 CONSTRUCTION PROCESS LOAD TESTING TIMELAPSE RESULT AND ANALYSIS CONCLUSION
DESIGN process1 BRACING MODEL1
STACKING MODEL1
MODULE1
V-shaped 29.7cm
-4setsofbracing Pro -Providesevendistributionofforce Con-Usesuptoomanysticks>lessefficiency -lackofslottingtechnique
COLUMNSMODEL1
-Setof3modules Pro-Goodstrengthasithasminimalmodules Con–heightbarelyreached30cm (minimum height)
PHOTO :BRACEDFLOORSLAB
-Setof5columns -3setsofbracings Pro–Strongsupportsystem atmostjoints Con–distributionofforcenotverysmoothassomejointsweremorefocusedon
PHOTO :MODULEEXPERIMENTATION
Doublelayer column -Bracedfloorslab -4unitsofcolumns Pro–verystrongsupportatmainjoints
-Thebracedfloorslabwasoneofthestrongestcomponentonthetoweritself
-Variousmethodswereexperimentedthroughoutthefirstdesignprocess
DESIGN process2 LOADDISTRIBUTIONANALYSIS
MODULE2
STACKING MODEL1
shorterby 3cm
37cm
shorterby 3cm
Thediagram showsthedistributionofforcethroughoutthestructureofthecolumns, beamsandbracings. 1)Loadwillcausetheforcetotraveldownthestructure.AsstatedinNewton'sThirdLaw, foreveryactionthereisequalandoppositereaction.Thisistrueasthereisoppositionof forcebetweentheloadandthestructure. 2)Acompressionbetweenthecolumn,beam andbracetodistributeequalamountsof forcetosupportthestructure. 3)Strongjointsbetweenhorizontalandverticalunitswhicharealsoslottedtogether helpsdistributesperpendicularforce. 4)Slotsinthestickswhichisjoinedbyanotherslotfillstheemptyspaceand strengtheningthestructure. 5)Ashorterbaseprovidesformorestrengthastheforcesdonotundergoweakpressure points.Thebracingsarealsoarrangedinsuchawaythatloadforceistransferreddirectly ontothegroundviathecolumns.
Setof5columns 4setsofbracings,oneoneachface Pro–verystrongstructure,withevenloaddistributionthroughout Con–jointsareslightlyunevenduetohumanerrorwhileconstructing
SLOTTING JOINTS
Thejointsbetweenthecolumnsandthebeam weredoneusingslottingmethodasitis theeasiestandsafestmethodtousewithoutstructurallyweakeningthesticks.
-Setof4modules -Firstandthirdmodule(from bottom)wereshorterthantheresttoprovidefor -strongerforceloadcapabilities heightsurpassedtheminimum height(37cm)
THREADREINFORCEMENT
Thejointscannotwithstandtheforcewithonlytheslottingmethod.Thereforethejoints werefurtherreinforcedusingthreadswrappedseveraltimestosecureitinplace.
construction process
1)straighten edgesofsticks
2)slotting in floorslabs
3)standing upcolumns
4)slotting in bracings
5)adding in second floorslab
7)3rd level
6)2nd level 8)finallevel
BUILDING CONSTRUCTION 2 PROJECT 1 - UNDERSTANDING FORCES IN A SKELETAL STRUCTURE
LOAD TESTING TIMELAPSE
1)baremodel -Modelfeelstoughandrigid
2)15KG -Modelstillhasitsstrengthandmaintainsitsoriginalshape
1)45kg -Modelstartstodeformbyaslightmarginonthemiddlelevels
2)60KG -Crackingsoundscanbeheardindicatingthejointsstressingout.After15secondsa 10kgweightwasaddedonanditeventuallybreak
3)30kg -Modelstillhasitsstrengthandmaintainsitsoriginalshape
3)BReaking POINT
RESULTAND ANALYSIS MODEL1
FINALMODEL
FAILURE/SUCCESSANALYSIS Thetowermanagedtosupportatotalweightof60Kg.Atthispointthetowerhadtelltalesignofimminent structuralfailurenamelythebendingofthesecondlevel'scolumns.furtherapplicationofweightfinallybreaksthecolumncausingtotalstructural failure. Thecolumnscanbeclearlyseenastheweakestpartofthestructureduetoitsspacedarrangement.Ifall membersofthestructurewereequallyasrigidandstrongfrom toptobottom,moreoftheforcefrom theloadwouldhavebeentransmittedtowardstheground.
MODELS
Thefactthatthetowerlevelsarenotequalinheightcouldalsomakeadifferenceinloaddistribution. However,itmustbestatedthatthereisapossibilitythefailurewasduetohumanerror;beitfrom thecuttingorfrom thewoodconditionitself.
HEIGHT
37CM
34CM
WEIGHT
100G
113G
WEIGHTSUSTAINED
40KG
60KG
NO.OFSTICKS
96
100
JOINTMETHOD
SLOTTING
SLOTTING
PROBLEM
HEIGHT
JOINTS
DIAGRAM :AFTERLOADTESTING
SOLUTIONTO IMPROVE
Asitisnearimpossibletocontrolhumanerror,structuraljointsshouldbemadeto becomemorerigidandstronger. Theadditionofextraunittofillinthespacebetweenthecolumnswhichisfastenedto bracethetwocolumnstogetherwoulddistributeforcesuniformlythroughoutthe tower,thusincreasingtheamountofloadthetowercancarry. Theheightofthetowerlevelscanbestandardisedtodistributetheforceequally.It canbeclearlyseenthateventhoughsomelevelofthetowerisstrongerbecauseof shorterheight,itbecomesuselesswhentheweakerpartofthetowerfailsthuscompromisingtheintegrityoftheentiretower.