Strength of Material Manual.PDF

7/28/2019 Strength of Material Manual.PDF

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SATI{YABAMA T]NWERSITYCHT',ITNAI6001I,9

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CONTENTSOFEXPERIMENTS PAGE

NO.

I9-10.

ON TEST ON WOOD 1)

COMPRESSION ESTON OPENCOILED .HELICAL SPRING 5TENSION TEST ON CLOSED COILED HELICAL SPRING S-TORSION TEST ON MILD STEEL ROI]ND BARZODIMPACT TESTTENSION TEST ON MILD STEEL BARROCKWELL HARDNESS TESTBRINELL HARDNESSTESTSHEARTESTON MILD STEELBAR

l l1 31 51 92 1Z J


3/25

I.COMPRESSION TEST ON WOOD/BRICKAIM :

To determinehecompressive trengthof agivenwoodenspecimen

APPARATUS REQTIIRED:I . ComPressionestingmachine2. Scale

PROCEDURE :

OBSERVATION :C . S dimensions f thesPecimen

Measurehedimensions f thespe:tlT* of the lowercompression-plate NowKeep the woodensPecimenlower the adjustablet'o" itJ by rotating the hand whee! so

that the top

[",T:ll'T##'m]"'*'#fJ.']";*:':;*:"1ifi:inTHfrffiH3:J"1#iliiilii;', .NotehertimateoadR".on" th" specimen from the machine '

1 .2.

4.5 .

TABULATION :Compressive trengthN / m m -rosssectionalareaof the sPecimen( m m - )


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C^{LCULATION:

Compressive trengthof the given specimen

RESULT :Thecompressivetrengthf thegiven pecimen=

Ultimatecompressiveoad

C. S areaof the specimen


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AIM :To determinehe Young's

law of reciProcaldeflectionAPPARATUS :

1. Knife edgesupports2. Deflectometer3. Setof weightswith hanger'4. Scale5. VemiercaliPerPRINCIPLE :

C . S . dimensionsf thebeamSpan I )Distance x )Distance a )Distance b )

2.DEFLECTION TEST

modulusof the given marerialand verif Maxwell's

AccordingtoMaxwell'slawofreciprocaldeflectioninasimplysupportedbeam6 e g = 6 e l*it"* O qB' Oeflectionof thebeammeasured t A due o the loadat B6 er - Oelectionof thebeammeasured t B due o the loadat APROCEDURE :

1 Measurehedimensionsof thebem-2. Place he gl.'* U.orn o fo'if" age "ryp*s *n equl overhangson eithersideof thebeam3. Placehedeflectometrat adituce a frm'lT sfit4. Placethe weight b-c* ; t d;t; of 'a' fiml'ih swort Note th initialreadingof thedefledoma'5. Now increasefte rJ-g;o#y md take the correspondingdeflectometerreadings' ie hedeflectometereadings'O. No* a"".t"utethe loadin thesamentervalsandno17. Drawa graPh Load vs Deflection

OBSERVATION :x < a & x < b

ItiI

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TABI]LATION :

CALCULATION:x < a w b x6 : i l 2 - b 2 - x 2 ;6 E I Ix < b w a x6 = 1 1 2 . : t - x 2 )6 E I IRESULT :

Young'smodulus f thegivenmaterial 0

Young'smodulusinN/mn2Deflectometer eading


7/25

3.COMPRESSION TEST ON OPEN COILED HELICAL SPRING

I

AIM :To conducta compression eston the givenhelical.spring

ndhenceq:"Y11:the ollowing, a) Shearmodulus b) Stiftiess of,thespring c) Proof load d) sffarnenergystoredatProof oadAPPARATUS :

1. Spring estingmachine2. VemiercaliPer3. ScaleMACHINE DESCRIPTION :

The machine mainly consistsof loading mechanism, oad measuringsystem,indicatingmechanism,ecorderandelectricalcontrols'LoadingmechanismThebase s connectedo torqueplateby two columns orming the main structureof themachineThemeasuring ystems assembledn top plate,and.is overed y,top;;;. Th" side panel fixed io ir" ,ieh, column consistsof indicating and recordingmechanismsLoad measuringsytems@endulumdynamometer):The oadmeasuringsystems supported nthe top plate a1d s coveredby thetopconer.Theuppergnp t eua t nxea rc G centrallTbtt

'A"priog

steelstrip-with onesndfixedto'thependulumshaftrunsarorrndtheshaftaoditsendisfixedtothecentralmember,Indicatingmechanism:-.-- Tfi rack pusher fixed to the pendulum ower prrsheshe rack which slidesovertherack juide pileys .The ower molvement f the rack rotates he pinion .Thepinion isil;J ;;; point". ,huft *t itg in ball bearing'. dummypointerwhichmoves orwardwith hemainpointer s provided or maximumoad eadingPROCEDURE :l 'Measurethemeancoildiameterandthediameterofwireofthespring.Alsonotethenumber.ofreecoils n thespring'2. Placethe pring n position n betweenheplatformsor compresstonpnng'3. Adjust he ndicator f the oaddial, o read '+'n'pplycompressiveloadbyincreasingatSuitableinter.valsandnotethecorrespondeflections.5. DrawgraPh load vs deflection

('


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VATION :diameter D )=

-tums( n )of thespring (H) :

TION:modulus G )

of the spring( K )

64 t 'n w------------ x -----d 4 6

6= K ( H - n d )load (wo )


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Sbealstress t P)

Slrain energy stored ( UwP)

RESTJLT :Rigidity modulusStiffrressof the spring

" Proof loadStrainenergy storedat proof load=

16woRnd3(tp)z n&= ___-----------4 G z D n


10/25

4.TENSIONTEST ON CLOSED COILED HELICAL SPRINGAIM :

To conducta tension eston thegivenhelicalspringandhencedeterminehefollowinga) Shearmodulusb) Stiffness f thespring.APPARATUS :

1. Springestingmachine2. Vemiercaliper3. ScaleMACHINE DESCRIPTION :. The machinemainly consistsof loadingmechanism,oad measuring ystem,indicatingmechanism,ecorder ndelectrical ontrols.Loadingmechanisrn:

Thebases connectedo torqueplateby two columnsorming hemainstructueof the machine. he measuring ystems assembledn top plateand s covered y topcover.The side panel fixed to the right columnconsistsof indicatingand recoidingmechanismsLoad measuring ystemsPendulum ynamometer):

The oadmeasuringysrems supportedn he opplateand s covered y the opcover-The ppergrip head s fixed to thecentralmember.A springsteelstripwith oneend ixed to the pendulum haft unsaroundhe shaftand ts end s fixed to thecentraLmember.IndicatingmechanismThe rack pusher ixed to thependulumower pusheshe rack which slidesoverthe ackguide ulleys The owermovementf the ack otateshepinion Thepinion sfixed on a pointershaft unning n ball bearing. dummypointerwhichmovesorwardwith hemainpointersprovidedor maximumoad eading

PROCBDURE

5 .

l . Measurehe meancoil diameter nd he diameter f rvireof the spring Alsonotethenumber f freecoi ls n thespringPlacehe spling n positionby attachingt to hooks or tension prin,uAdjust he ndicatorofthe loaddial ,to read0 .Apply tensile oad by increasing l suitablentervalsanclnote lre corfespondinsdcflccionsDlaw graph load vs dellectron.

2 .-).4.


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OBSERVATION :Meancoil diameter D)Wirediameter d )No.of freecoils n )

TABULATION :

CALCULATION:

It igiditymodulLrsG )

Stiflness f the spring K )

Shear tr 'ussr )

6 4 R r n w,.:l -c t d

616 v l

Deflection (mm )

r d l


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Strain energystored ( Uwp )

RESULT :RigiditymodulusStiffness f the springProof oadStrci enelgy tore(l l

( r ) -; ;

7r d---------- x n Dn4

I

liI

, . - ^ . - f t ^ ^ rP r U U r l u i l L t -


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s.TORSION TEST ON MILD STEEL ROUND BARAIM:

To conduct torsion eston thegivenmild steelwireandhence eterminehemodulus f rigidity .APPARATUS :

i . Torsion estingmachine2. Verniercaliper.3. ScaleMACHINE DESCRIPTION:

The machine onsists f two unitsnamely,oadingunit and hemeasuringontrolpanel. t consistsof robustbase itted with controlpanel.The gearbox assemblysguidedon thebase.A drivingchuckandanglemeasuringulley is mountedon a leveripindleassemblys connectedo a pendulum ynamometer.he autographicecordersfi'tt"don the controlpanel The ecorderwill show herelationbetweenorqueand wistanglePROCEDURE

1. Measurehe diameter f the specimenn bothperpendicularirections nd aketheaverage2. Fix thespecimen etweenhedrivingchuckand hedrivenchuck'3. Set heanglemeasuringialat0oposit ion.4. Now apply orque o the sPecimen.5. Note he orque eadings y changinghe angleof twist.6. Draw hegraph orqueVs angleof twist.

OBSERVATIONS:Length f thespecimenI )D ia rne t r r , ' lhe pcc i rnend )

l l


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TABULATION :

CALCULATIONS

PolarM.I. (J)

Rigiditymodulus(G )

RESULT:Modulusf rigidity f thegivenmaterials

, 17r d')z

TU

Ix ------J

t2


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6.IZOD IMPACT TESTAIM :

To determinehe mpactstrength f thegivenspecimen.APPARATUSREQUIR.ED:

1. Izod mpact estingmachine2. ScaleMACHINEDESCRIPTION:

The pendulummpact estingmachine onsists f the singlepiece rame, hependulum,hespecimen upport nd he measuring quipment.he pendulums fastenedto the pendulumshaft.The rangewithin whichthe pendulum s swinging s partiallyprotooted y theguard.There s a dial attached oncentrically ith the pendulum haft.The scale s designeduch hat he mpactenergy bsorbedn breakinghe specimen anbe eaddirectly.Angle of drop of pendulumStrikingvelocityof pendulumPROCEDURE:

= 900: m / s e c

I . Firmly secure he proper striker to the bottom of the hammer with the help ofdampingpiece.2. Firmly secure he latching tube for Izod test to the baning housing at the side ofthe columns. The steel wire coming from the latch is carried ttnough the latchingtubeand s fastened o the interior of the release ever.3. For determininghe frictional oss n themachine, djust he readingpointeralongwith pointercarrier o 300 J readingon the dial wl.renhe pendulum s swingingtree.4. Note he reading n the scaleagainst he pointer,whichgives nitial eror ifan1,.5 . Now i f t hependu l r rmga i r ru r ss r r r r i ngos i r ron .6. Fix the specimenor lzod tesi o thc sq)ltort.7. I le leasehependulunrs rcl i r lc.[ 'hehanrntel tr ikeshespecinten.

ll . 'Note the reaciingagainst hc pointer. I'his givcs the enelgy absorbedby' rh:specinren.

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ORSERVATION:Lengthof the specimenEffectivecross-sectionalreaEnergyabsorbed y thespecimen

TABULATION:

CALCULATION:

Impactstrength Energyabsorbedy thespecimenEffective cross-sectional rea

RESULT:Impactstrength fthe givenspecimen

t 4


17/25

7. TENSION TEST ON MILD STEEL BARAIM: To study he behaviourof a mild steelspecimen nder ensionwhentested odestructionndalso o determinehe ollowing.a) Young'smodulus b) Yield stress c) Ultimatestress d) Breakingstresse) Percentagelongationn length f) Percentageeductionn area.

APPARATUSEQUIRED1 Universalestingmachine2. Extensometer3. Vemier aliper4. Scale

DESCRIPTIONOF MACHINE :The machine onsists f two unitsnamelyl. The oadingunit2. The controlunit.The loadingunit consistsof a robustbase.The rnainhydrauliccylinder s to befitted n the centreof the baseand he pistonslides n the cylinder. t consists f a lowertable,which is connectedo the main piston hrougha ball and ball seal oint and twocrossheads. he ower tableand he uppercross eadassemblymovesup anddown withthe mainpiston.

The main units n the controlpanelareL The oil tar.rkvhichcontains he hydraulicoil.2. The pump which assuresa continuoushigh pressure on - pulsating of cunent forthe smoothapplioation f loadon the specimen.3. 'fwo valvesont: at the right hand side and the other at the left side are used ocontrol he oil flow in the hydraulicsystemand Dynamometer s a unit whichmeasures nd indicates he load. lt is a pendulumclynantometeronsisting f acylinder n rvhich he piston eciprocales.4. 'l'hedisplaccment f the pistoncariseshe pendr.rlr.imo deflec1 nd this deflectionrepresentsi ic teastr lenrcr i tf the oadon thespccirucn.' r l tt iot{Y:

Within the elast ic inr i t lbr duct i lc nratel ia ls . t ress rcars r cor ' rs t . rntat io rv i th hi 'appl iedsl ress. \ /hen he tcs l s iu lp lc js tcstct ibr , r ,arr inq l te s t ress n t l - f l \4 at the inte o l 'I ' ic ld. thc p() i11tlcps i ) f a l ] tonrcnt . ' l 'h isn ' i l l bc l i r l los,cc l y the scal ing o1f f i - ont hcs r t t i i t c ei l t l t cs l t c c i n r t n .: t t r l l t e rn u ' c r r s cn l L , e t lr i l l l r e h c r r l t i i n a t eo a da n d h i su i l l b eshor. 'unr t l tc lunt t t t ,vntLic i (or n thc Lol i i i caleant l l rc blcaking oacln ' i l l be s i tor in brthe ac l i lc jndicatr i lneecl lc v l ten1he pccinten i r i ls .

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PROCEDURE:Initial adiwtmen, ":.T.:, t" testing,adjust he pendulumweightaccordingoff"ffit:"flJ: the est'Adjusthecorresp-ondingung.'onhedial ft,r,tr*-.*i"'-1 Measure he diameterof the specimenn two directionsperpendicular o each., :1T,1?l^.T-,r hreetaces_onhi barandak" h"uu"rug"z, LvlatK e gaugeengthon thebar.3. Select the appropriate.measuring ange by placing proper weights on theendulumf the U . T. M.Fix oneendof themild steelbar n theclamping awsof theU. T. MN9y aajrlgthe ofter head o.rhe "qrir"d;i;;L; *lg.,p theotherendof thejld ste,el ar n theclamping3awsnrt.u ta.mpheextensometer.Apply the..oad graduallyby .opening he right control valve and note theorrespondingxtensometereadins.

At.a particular tageherewill bea-pausen the ncrease f load.The oadat thatoint snoted syieldpoint oad.After the pointer eacheshemaximum, herewill be a suddendrop n the loadand his s recorded sultimateoad.

+.5 .6.7.8 .9.10.A neck s formedat the centerof the specimenndcontinue he oadingwith aummypointeraccompanvinghe load pointeruntil ih;;iri';r";ft;r##r._ Note hebreakingoadat the imeof fractirre.1. Now close he ightconholuutu".R..ou" tt. specimenromthemachine.? Y:^y. the inal lengthand hediameter f ifr"'.rila steelbar.r' L arculatehestress"1q rt.uinfor each eadingandplot a graph.Slopeof the ineives heModulusof Elasticitv.

OBSERVATION:Diameter f thespecimenD)Gaugeengthof thespecimenL)Neckdiameter fter racture(D;) :Finalgaugeengthafter racture Lr)Yield oadUltimateoadBreakingoad

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19/25

00

r00

TABULATION:

CALCULATION:In t ia lcross-sectionalrea A.1

Finai cross-sectional rea A1)

% reduction n area

ou Elongationn lcngrl t

Yieldstress

Initial area FinalareaInitialarea

Final ength Ini t ia! ength-------------xIn i t i a l cng thYielcl oacl

Ini t ia l i 'oss-sectionalrea

I t inrateoad

Sl. No Load Extensometer eadingmm Strain StressN/mm2 Young'sModulusN/mm2gf N Dial Dial I Meanl . I I.3 .4.5 .6.7 .

Llltimatestress

I 7

ln i l ia lcross-sectionalrea


20/25

NominalBreakingstress

ActualBreakingshess

Young'smodulus

RESULT:l. Young s modulus2. Yieldshess3. Ultimatestress4. Nominalbreaking tress5. ActualBreaking tress6. oZreductionn area7. % elongationn length

Breaking oad

Originalareaof crosssection

BreakingoadFinal areaof crosssection

Axial stressAxial strain

l 8


21/25

S.ROCKWELL HARDNESS TESTAIM :

To find theRockwellhardnessumberor thegivenmaterials'GENERAL:

TheRockwellhardnessest s ofthe staticndentationypeand heRockwellhardnessumbers based n theadditional epth o which apenetrators drivenby aheavyoadbeyondhedepth o whichapenetratorasbeendrivenby a definite ightload The ollowing ndentors reusedn Rockwellhardnessestera) Diamond one ndentorwith a topangleof 120"'b ) Steelballof diameterl 16 .Load ange6C 100, 150kg.APPARATUS REQUIRED:

Rockwell hardnessestingmachineStopwatch

t .2.

PROCEDURE :1. Put theweightson plungerof dash-pot ccordingo theRockwellscale equired

by turning he.,Loadselector isc", he respectiveignreof weightwill bevisiblein thewindow.2. Keep he everat PositionA.3. Place hespecimen ecurely n thework able4. Turn the handwheelclockwise othat the specimenwill push he indentorandshow a readingon dial gaugeas small pointerat '3' The long pointerautomaticallytops t 0' onblack cale i e ) 'B' 30 on redscale5. Turn he evLr rompositionA' to B' slowlyso hat he otal oad s broughtnto6.1.

actionwithout anY erks.when tlre ong pointerof dial gauge e.lches stead,vosition" akeback lre everto 'A' posi t ion lorvl l ' .Reacl il the ligure againsl he lo'g printer. 1'hisgives the R.ckwell hardnessrt trlber

8. -l'urnback he harlcl 'heelancl entove he specimen'ronl hc nlachine. arry onthe sameprocedureor iirrtherspccirnens.

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22/25

1

TABULATION :

RESULT :The Rockwellhardness umber or

S l No Specimen Loadk g f

Indentor Scale RoclavellhardnessnumberTrial I Trial 2 Trial 3 Mean

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23/25

9. BRINELL HARDNESSTESTAIM :

To detemiine heBrinell hardness umber or the givenspecimens.APPARATUS :

1.Brinellhardnessestingmachine.2. Microscope.bnscnrpuoN oFMACHINE

Themachine onsists f a 'J' frame,main ever,hanger, levating crew,oadingunloadingmechanism nddamper ystem. he load s appliedon the specimenhroughballholder,t is effectedhrougha evermechanism.The main lever carries hreemale vees,onefor hanger,second or spindle shaftand hird for pivot vee. The elevating screwcanbe movedup anddown by rotating thehandwheel.The five detachable eights,eachequivalento 500 kg and o bemadeuseof for application f desiredoad n addition o the bottomweight equivalento 500kg.Theoperatingever s provided or loadingandunloading.PROCEDURE :

1 .2.) .4.5 .

Polish he surface f the specimen.Placehe specimen nthe worktable.Keep he operatingever n horizontal osition.Turn thehand wheel n clockwisedirectionso hat he specirnenouchesheball indentor.Lift theoperatingever rom horizontal ositionupwards lightlyafterwhichit rotates utomatically.6. Wait till the everbecomestandstill.7. Bring he everback o horizontal osition.8. Turn back hehandwheeland emove he specimenlom themachine.Canyon the same rocedurebr furtherspecimens.9. Measurehediameterf impressiony BrinellMicroscope10.Find heBrinellhardnessr"rmbersing he ormula

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24/25

FORMULA:BrinellHardness umberWhereP - load n Kgf

D - Dia.of indentern mmd - Dia.of indentationn mmForSteel p:30 D2ForBrass , p= l0D2ForAluminium,P= 5D2

OBSERVATIONS:Diameter f indentor D =Diameter f indentation, :

TABULATION :

n D / 2 I D - r / 1 O , - a r ; 1

S l N o Specimen Diameterofindentor D(mm)Loadkgf Diameterof impression- (mm) BrinellhardnessnumberrialI Trial2 Tr ia l3 Mean

RBSULT :Brinellhardness umber or lhe givenspecimen5

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10.SHEAR TEST ON MILD STEEL BAR

To find the shearstrengthofthe given specimenAPPARATUS REQUIRED :1 Universal estingmachinewith shear ttachment2. Vemier aliper.PROCEDURE :1. Measurehe dimensionsf the specimen2. Place he shearestattachmentnthe ower ableof U.T.M. and ix the estspecimenn the shearestattachment3. Apply the oadon the specimen radually4. Note hedialgaugeeadingwhen he specimenailsOBSERVATION :Diameter f thespecimen d )Loadat the imeof failure P )TABULATION :Sl .No Typeofshear Diameterofspecimenmm )

Area ofspecimen(mm2 Shear oad(Kg f )Shearstrength(N mm')

CALCULATION :Area of tl.re pecimen A )Shear trength f thespecimen P l2 A)

ITESTII-'TI h. 'she.rrtrcr lglh ) l ' thc pecinten

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Strength of Material Manual.PDF