design and analysis of connecting rod for reduction of weight and cost report

8/10/2019 Design and Analysis of Connecting Rod for Reduction of Weight and Cost Report

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CHAPTER 1

INTRODUCTION

The automobile engine connecting rod is a high volume production, criticalcomponent. It connects reciprocating piston to rotating crankshaft, transmitting the throf the piston to the crankshaft. Every vehicle that use an internal combustion enginerequires at least one connecting rod depending upon the number of cylinders in theengine.

Connecting rods for automotive applications are typically manufactured

forging from either wrought steel or powdered metal. They could also be caHowever,castings could have blow holes which are detrimental from durability afatigue points of view. The fact that forgings produce blow hole free and better rods githem an advantage over cast rods !"upta, #$$%&. 'etween the forging processes, powforged or drop forged, each process has its own pros and cons. (owder metmanufactured blanks have the advantage of being near net shape, reducing materwaste. However, the cost of the blank is high due to the high material cost asophisticated manufacturing techniques !)epgen, #$$*&. +ith steel forging, the mateis ine pensive and the rough part manufacturing process is cost effective. 'ringing th part to final dimensions under tight tolerance results in high e penditure for machinias the blank usually contains more e cess material !)epgen, #$$*&. - si eable portion the /0 market for connecting rods is currently consumed by the powder metal forgiindustry. - comparison of the European and 1orth -merican connecting rod marketindicates that according to an unpublished market analysis for the year 2333 !4udenba2332&, 5*6 of the connecting rods in Europe !total annual production7 *3 mil

appro imately& are steel forged as opposed to 8%6 in 1orth -merica !total annu production7 #33 million appro imately&, as shown in 9igure #.#. In order to recaptur/0 market, the steel industry has focused on development of production technology anew steels. -I0I !-merican Iron and 0teel Institute& funded a research program that htwo aspects to address. The first aspect was to investigate and compare fatigue strengt

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1.1 OBJECTIVE AND OUTLINE

The ob?ective of this work was to optimi e the forged steel connecting rod for weight and cost. The optimi ed forged steel connecting rod is intended to be a moattractive option for auto manufacturers to consider, as compared with its powder forcounterpart.

@ptimi ation begins with identifying the correct load conditions anmagnitudes.@verestimating the loads will simply raise the safety factors. The idea be

optimi ing is to retain ?ust as much strength as is needed. Commercial softwares suc()@ E and -10A0 Biew can be used to obtain the variation of quantities such asangular velocity,angular acceleration, and load However, usually the worst case loaconsidered in the design process. 4iterature review suggests that investigators uma imum inertia load,inertia load, or inertia load of the piston assembly mass as oe treme load corresponding to the tensile load, and firing load or compressive gas locorresponding to ma imum torque as the other e treme design load corresponding to tcompressive load. Inertia load is a time varying quantity and can refer to the inertia lof the piston, or of the connecting rod. In most cases, in the literature the investigathave not clarified the definition of inertia load whether it means only the inertia of piston, or whether it includes the inertia of the connecting rod as well. uestions anaturally

raised in light of such comple structural behavior, such as7 >oes the peak load at ends of the connecting rod represent the worst case loadingD /nder the effect of bendand a ial loads, can one e pect higher stresses than that e perienced under a ial load

aloneD C, and the ma imum bending stress at tcolumn center is about 2 6 of the ma imum stress at that location. However, to obtai

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the bending stress variation over the connecting rod length, or to know the stresscritical locations such as the transition regions of the connecting rod, a detailed analis needed. -s a result, for the forged steel connecting rod investigated, a detailed loanalysis under service operating conditions was performed, followed by a quasi dyna9E- to capture the stress variation over the cycle of operation.

4ogically, any optimi ation should be preceded by stress analysis of the e istincomponent, which should be performed at the correct operating loads. >iscusses suissues as mesh convergence, details of how loads and restraints have been applied, validation of the 9E model for three cases static 9E-, quasi dynamic 9E-, and tesassembly 9E-. Chapter 8 discusses the stress time history, ) ratio and multia iality o

stresses for various locations on the connecting rod under service operaticonditions.This indicates the e tent of weight reduction to e pect through optimi atioidentifies the regions from which material can be removed, or regions that need toredesigned.This chapter also discusses the static 9E- results and makes a comparis between the static 9E-, quasi dynamic 9E-, and results from test assembly 9E-.@ptimi ation of the connecting rod is addressed in Chapter . @ptimi ation w performed to reduce the mass and manufacturing cost of the connecting rod, sub?ecfatigue life and yielding constraints. The material was changed to C 53 fracture splitasteel to reduce manufacturing cost by elimination of machining of mating surfaces ofconnecting rod and it:s cap. 0 1 approach was used for the fatigue model during thoptimi ation, as the connecting rod operates in the elastic range !i.e. high cycle fatiglife region&. - comparison between the various manufacturing processes and their cosalso presented.

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CHAPTER 2 LITERATURE REVIEW

The connecting rod is sub?ected to a comple state of loading. It undergoes hicyclic loads of the order of #3* to #3$ cycles, which range from high compressive lodue to combustion, to high tensile loads due to inertia. Therefore, durability of tcomponent is of critical importance. >ue to these factors, the connecting rod has beentopic of research for different aspects such as production technologmaterials,performance simulation, fatigue, etc. 9or the current study, it was necessaryinvestigate finite element modeling techniques, optimi ation techniques, development production technology, new materials, fatigue modeling, and manufacturing cost analyThis brief literature survey reviews some of these aspects.

+ebster et al. !#$*%& performed three dimensional finite element analysis ohigh speed diesel engine connecting rod. 9or this analysis they used the ma imucompressive load which was measured e perimentally, and the ma imum tensile lowhich is essentially the inertia load of the piston assembly mass. The load distributi

on the piston pin end and crank end were determined e perimentally. They modeled connecting rod cap separately, and also modeled the bolt pretension using beam elemand multi point constraint equations.

In a study reported by )epgen !#$$*&, based on fatigue tests carried out identical components made of powder metal and C 53 steel !fracture splitting steel&notes that the fatigue strength of the forged steel part is 2#6 higher than that of th

powder metal component. He also notes that using the fracture splitting technoloresults in a 2 6 cost reduction over the conventional steel forging process. These factosuggest that a fracture splitting material would be the material of choice for steel forconnecting rods. He also mentions two other steels that are being tested, a modifmicro alloyed steel and a modified carbon steel. @ther issues discussed by )epgen are

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necessity to avoid ?ig spots along the parting line of the rod and the cap, needconsistency in the chemical composition and manufacturing process to reduce variancmicrostructure and production of near net shape rough part.

(ark et al. !233%& investigated microstructural behavior at various forgconditions and recommend fast cooling for finer grain si e and lower network ferrcontent. 9rom their research they concluded that laser notching e hibited best fractusplitting results, when compared with broached and wire cut notches. They optimi ed fracture splitting parameters such as, applied hydraulic pressure, ?ig set up and geomof cracking cylinder based on delay time, difference in cracking forces aroundness.They compared fracture splitting high carbon micro alloyed steel !3.56

with carbon steel !3.8*6 C& using rotary bending fatigue test and concluded thatformer has the same or better fatigue strength than the later. 9rom a comparison of fracture splitting high carbon micro alloyed steel and powder metal, based on tensicompression fatigue test they noticed that fatigue strength of the former is #*6 highthan the later.

0arihan and 0ong !#$$3&, for the optimi ation of the wrist pin end, used a fatiload cycle consisting of compressive gas load corresponding to ma imum torque atensile load corresponding to ma imum inertia load. Evidently, they used the ma imuloads in the whole operating range of the engine. To design for fatigue, modifi"oodman equation with alternating octahedral shear stress and mean octahedral shstress was used. 9or optimi ation, they generated an appro imate design surface, an performed optimi ation of this design surface. The ob?ective and constraint functiwere updated to obtain precise values. This process was repeated till convergence wachieved. They also included constraints to avoid fretting fatigue. The mean and alternating components of the stress were calculated using ma imum and minimumvalof octahedral shear stress. Their e ercise reduced the connecting rod weight bynearly 256.

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Aoo et al. !#$*8& used variational equations of elasticity, material derivative ideacontinuum mechanics and an ad?oint variable technique to calculate shape dessensitivities of stress. The results were used in an iterative optimi atioalgorithm,steepest descent algorithm, to numerically solve an optimal design problThe focus was on shape design sensitivity analysis with application to the e ample oconnecting rod. The stress constraints were imposed on principal stresses of inertia firing loads.'ut fatigue strength was not addressed. The other constraint was the one thickness to bound it away from ero. They could obtain 236 weight reduction in thneck region of the connecting rod.

Hippoliti !#$$%& reported design methodology in use at (iaggio for connec

rod design, which incorporates an optimi ation session. However, neither the detailsoptimi ation nor the load under which optimi ation was performed were discussed. Tw parametric 9E procedures using 2> plane stress and %> approach developed by author were compared with e perimental results and shown to have good agreemenThe optimi ation procedure they developed was based on the 2> approach.

El 0ayed and 4und !#$$3& presented a method to consider fatigue life asconstraint in optimal design of structures. They also demonstrated the concept on a 0key hole specimen. In this approach a routine calculates the life and in addition to stress limit, limits are imposed on the life of the component as calculated using 9results.

(ai !#$$F& presented an approach to optimi e shape of connecting rod sub?ecto a load cycle, consisting of the inertia load deducted from gas load as one e treme a peak inertia load e erted by the piston assembly mass as the other e treme, with fatiglife constraint. 9atigue life defined as the sum of the crack initiation and crack growlives, was obtained using fracture mechanics principles. The approach used finite elemroutine to first calculate the displacements and stresses in the rodG these were then usa separate routine to calculate the total life. The stresses and the life were used inoptimi ation routine to evaluate the ob?ective function and constraints. The new sea

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direction was determined using finite difference appro imation with design sensitivanalysis. The author was able to reduce the weight by 2*6, when compared with toriginal component.

0onsino and Esper !#$$8& have discussed the fatigue design of sinteconnecting rods. They did not perform optimi ation of the connecting rod. They desiga connecting rod with a load amplitude 9a #$.2 k1 and with different regions beindesigned for different load ratios !)&, such as, in the stem 9m 2.2 k1 and ) #.2F, atthe piston pin end 9m . k1 and ) #.*2, at the crank end 9m 5.* k1 and ) 3.82. They performed preliminary 9E- followed by production of a prototype. 9atigtests and e perimental stress analysis were performed on this prototype based on t

results of which they proposed a final shape, shown in 9igure #.8. In order to verify the design was sufficient for fatigue, they computed the allowable stress amplitudecritical locations, taking the ) ratio, the stress concentration, and statistical safety factointo account, and ensured that ma imum stress amplitudes were below the allowabstress amplitude.

9or their optimi ation study, 0eraget al. !#$*$& developed appro imate

mathematical formulae to define connecting rod weight and cost as ob?ective functiand also the constraints. The optimi ation was achieved using a "eometric (rogrammintechnique. Constraints were imposed on the compression stress, the bearing pressurthe crank and the piston pin ends. 9atigue was not addressed. The cost function we pressed in some e ponential form with the geometric parameters.

9olgaret al. !#$*5& developed a fiber 9(


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'alasubramaniamet al . !#$$#& reported computational strategy used in


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screws, the diametral interference between the bearing sleeve and the crank end of connecting rod, the diametral clearance between the crank and the crank bearing, inertia load acting on the connecting rod, and the combustion pressure. The analyclearly indicated the failure location at the thread root of the connecting rod, causedimproper screw thread profile. The connecting rod failed at the location indicated by9E-. -n a isymmetric model was initially used to obtain the stress concentrationfactorsat the thread root. These were used to obtain nominal mean and alternating strein the screw. - detailed 9E- including all the factors mentioned above was performed balso including a plasticity model and strain hardening. 'ased on the comparison of tmean

stress and stress amplitude at the threads obtained from this analysis with t

endurance limits obtained from specimen fatigue tests, the adequacy of a new design checked.4oad cycling was also used in inelastic 9E- to obtain steady state situation.

In a published 0-E case study !#$$5&, a replacement connecting rod with #8weight savings was designed by removing material from areas that showed high factosafety. 9actor of safety with respect to fatigue strength was obtained by performing 9with applied loads including bolt tightening load, piston pin interference locompressive gas load and tensile inertia load. The study lays down certain guideliregarding the use of the fatigue limit of the material and its reduction by a certain fato account for the as forged surface. The study also indicates that buckling and bendstiffness are important design factors that must be taken into account during the des process. @n the basis of the stress and strain measurements performed on the connecrod, close agreement was found with loads predicted by inertia theory. The study alsoconcludes that stresses due to bending loads are substantial and should always be tainto account during any design e ercise.

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CHAPTER 3

STUDY OF CONNECTING ROD

3.1 FUNCTION OF CONNECTING ROD

The main function of the connecting rod is to convert the pistons reciprocatimotion into rotary motion with the crank shaft.The connecting rod acts as the li between the crosshead and crank shaft of the engine.

+hen doing a force balance of the piston motion,the mass of all the parts which aconsidered to reciprocate with the piston must taken into account.These include

piston,the piston rings,the piston pin and the equivalent mass of the upper end of connecting rod.

%.#.#


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- mechanism is a constrained kinematic chain.ouble slider crank mechanism

%.2


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The kinematic structure of a mechanism refers to the identification of the ?oconnection etween its links. Kust as chemical compounds can be represented byabstract formula and electric circuits by schematic diagrams, the kinematic structurmechanisms can be usefully represented by abstract diagrams. The structure mechanisms for which each ?oint connects two links can be represented by a structdiagram, or graph, in which links are denoted by vertices, ?oints by edges, and in whthe edge connection of vertices corresponds to the ?oint connection.

%.2.2 C)-1J -1> 04@TTE> L 4EBE) /ICJ )ET/)1


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Even within one mechanism type, many different link length combinations may perfothe required task.

%.2.%+HIT+@)TH /ICJ )ET/)1


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%.% 4@->I1" @9 C@11ECTI1" )@>

There are different types of loads acting on the connecting which virtually leto its failure.

Connect n! "o#$ %"e $&'(ecte# to

#. Inertia forces due to mass2. 9orces generated from the combustion process%. 9orces due to wearing of forging flashes

T)e$e *o"ce$ +"o#&ce

#. Cyclic a ial forces and stress2. Cyclic bending moment and stress !perpendicular to the crankshaft a is&%. Cyclic bending moment and stress !parallel to the crankshaft a is&

3., PROPERTIES CONCERNING THE CONNECTING ROD

3.,.1 -ODULUS OF ELASTICITY

-n e %$t c /o#& &$ , or/o#& &$ o* e %$t c t0 , is the mathematical

description of an ob?ect or substanceNs tendency to be deformed elastically !i.e., non

permanently& when a force is applied to it. The elastic modulus of an ob?ect is define

the slope of its stress strain curve in the elastic deformation region.

3.4.2 HARDNESS

Hardness is the measure of how resistant solid matter is to various kinds

permanent shape change when a force is applied.


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>eformation is a change in the shape or si e of an ob?ect due to an applied force.

3.,., YOUNG S -ODULUS E

Aoung:s modulus !E& is a measure of the stifness of a given material.

E 0T)E00 0T)-I1

3.,.4 STIFFNESS 5

0tiffness is the resistance offered by an elastic body to deflection o

deformation by an applied force.It is an e tensive material property.

3.,.6 THER-AL E7PANSION COEFFICIENT

Thermal e pansion is the tendency of matter to change in volume in responto a change in temperature.


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at atmospheric pressure. - liquid in a high pressureenvironment has a higher boiling po

than when the liquid is at atmospheric pressure. In other words, the boiling point o

liquid varies dependent upon the surrounding environmental pressure !which tend

vary with elevation&. >ifferent liquids !at a given pressure& boil at different temperat

3.,.9 CRITICAL TE-PERATURE

The critical temperature of a substance is the temperature at and abov

which vapor of the substance cannot be liquefied, no matter how much pressure

applied.-s the critical temperature is approached,the properties of the gas and liqu

phases become the same resulting in only one phase the supercritical fluid.

3.,.: DENSITY

>ensity is mass !


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The specific heat is the amount of heat per unit mass required to raisthetemperature by one degree Celsius. The relationship between heat and temperatchange is usually e pressed in the form shown below where c is the specific heat.

3.4 TYPES OF CONNECTING ROD

9ig %.#Connecting )od

#. I L 'E-< )@>02. H 'E-< )@>0

%. -4/08. (@+E)E> 0. TIT-1I/< )@>0

3.4.1 I=BEA- RODS

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I beams are commonly made of structural steel but may also be formedfromaluminium or other materials. - common type of I beam is therolled steel

joist !)0K& sometimes incorrectly rendered as reinforced stee ?oist.'ritish andEuropean standards also specify /niversal 'eams !/'s& and /niversalColumns !/Cs&. These sections have parallel flanges, as opposed to the varying thickof )0K flanges. /Cs have equal or near equal width and depth, while /'s aresignificantly deeper than they are wide.

I beams engineered from wood withfiberboard and or laminated veneer lumber are also becoming increasingly popular in construction, especially residential,they are both lighter and less prone to warping than solid wooden ?oists. However therehas been some concern as to their rapid loss of strength in a fire if unprotected.

3.4.2 H=BEA- RODS

H beam connecting rods comes up every once in awhile, and it:s a fun topic f bench racing. 'ut one thing I:ve noticed is that many enthusiasts have the mistakimpression that cylinder pressure loads, such as from superchargers or turbochargerwhat fails connecting rods. This tends to be reinforced by many connecting r

companies that rate connecting rods by horsepower. -ll connecting rods are designedwithstand incredibly high compressive loads. This is not what typically will cause ato fail. +hat tends to damage or fail a connecting rod is the change in directionespecially at bottom dead center !'>C& when the rod is sub?ected to tension and the bolts are strained to prevent the cap from pulling apart from the rod. This makes engspeed, rpm, the real connecting rod killer. +eight is another big factor, which is usuall bedfellow to strength. 'ut the reality is that a lighter rod is most often better in an rpapplication since the lighter rod presents less of a g force load on the cap and rod boThis also makes the selection of a connecting rod bolt as important as the rod its-nother point worth considering is that the big end of an H beam rod tends to take more space than an I beam, which makes clearance an issue when it comes to strocranks. -ll this places the selection of I beam versus H beam far down on the list oimportant selection criteria.

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http://en.wikipedia.org/wiki/Structural_steelhttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/British_Standardhttp://en.wikipedia.org/wiki/European_Committee_for_Standardizationhttp://en.wikipedia.org/wiki/Fiberboardhttp://en.wikipedia.org/wiki/Laminated_veneer_lumberhttp://en.wikipedia.org/wiki/Laminated_veneer_lumberhttp://en.wikipedia.org/wiki/Joisthttp://en.wikipedia.org/wiki/Structural_steelhttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/British_Standardhttp://en.wikipedia.org/wiki/European_Committee_for_Standardizationhttp://en.wikipedia.org/wiki/Fiberboardhttp://en.wikipedia.org/wiki/Laminated_veneer_lumberhttp://en.wikipedia.org/wiki/Laminated_veneer_lumberhttp://en.wikipedia.org/wiki/Joist


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3.4.3 ALU-IU- RODS

-luminium rods are popular among high rpm race engines. They are very ligand strong, but they a short fatigue lift. In a limitied use situation, they can last a lo

time and usually those types of engines see frequent tear downs anyway. They do not many miles in a street car. They are not out of the question for a street car, is rpm is kdown to about 5333 rpm or under and doesn:t see that rpm often, they can last quitwhile. Even then, # 23,333 miles will be about ma imum.

They also need more piston to head clearence due to more rod stretch, a typialuminuim rod in a high rpm aplication. 0ince aluminium atrengths more than ste bearing retention is also a problem. The usual tangs are not enogh to be reliab

-luminium rods must use a dowel pin to keep the bearings from spinning.

3.4.4 POWDERED -ETAL RODS


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Titanium connecting rods are one of the automotive components that wedesigned and created specifically for the high stress factors and the need of ma imu performance that is encountered in the automotive racing industry. They haven:t leftracing arena insofar, with the possible e ception of the perfectionist amateurs and some high profile, high priced, high speed street cars such as the -cura 10P, Corvette o(orsche "T% that were reported of using titanium connecting rods.

CHAPTER ,

OPTI-I>ATION OF CONNECTING ROD

,.1 -ATERIALS USED FOR CONNECTING ROD PTI-I>ATION

STEELS

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C-)'@1 0TEE4

9@)"E> 0TEE4

-44@A 0TEE4

0T-I14E00 0TEE4

T@@4 0TEE4

ALU-INU-

-4/E

-4/


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can contain a small amount of carbon, but it is included in the form of slag inclusioTwo distinguishing factors are steelNs increased rust resistance and better weldability.

,.1.2 CARBON STEEL

Carbon steel, also called plain carbon steel, is steel where themain alloying constituent iscarbon. The -merican Iron and 0teel Institute !-I0I& defincarbon steel as7 Q0teel is considered to be carbon steel when no minimum contespecified or required chromium,cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium or onium, or any other element to be added to obtain a desired alloying effectG when

specified minimum for copper does not e ceed 3.83 percentG or when the ma imucontent specified for any of the following elements does not e ceed the percentagnoted7 manganese #.F , silicon 3.F3,copper 3.F3.Q

The term Qcarbon steelQ may also be used in reference to steel which is not stainless in this use carbon steel may include alloy steels.

-s the carbon content rises, steel has the ability to become harder and stronger through heat treating, but this also makes it less duc)egardless of the heat treatment, a higher carbon content reduces weldability. In carbsteels, the higher carbon content lowers the melting point.

,.1.3 ALLOY STEEL

-lloy steel is steel alloyed with a variety of elements in total amounts o between #.36 and 36 by weight to improve its mechanical properties. -lloy steels are broken down into two groups7 low alloy steels and high alloy steels. The difference between the two is somewhat arbitrary7 0mith and Hashemi define the difference at 8while >egarmo, et al., define it at *.3 6.


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Properties CarbonSteels

AlloySteels

StainlessSteels

ToolSteels

Density (1000 kg/m 3) 7.85 7.85 7.75-8.1 7.72-8.0

Elastic Modulus ( !a) 1"0-210 1"0-210 1"0-210 1"0-210

!oisson#s $atio 0.27-0.3 0.27-0.3 0.27-0.3 0.27-0.3

%&e'mal E ansion (10 -* /+) 11-1*.* ".0-15 ".0-20.7 ".,-15.1

Melting !oint ( ) 1371-1,5,

%&e'mal onducti ity ( /m-+) 2,.3-*5.2 2*-,8.* 11.2-3*.7 1"."-,8.3

eci ic eat (4/kg-+) ,50-2081 ,52-1,"" ,20-500

%ensile t'engt& (M!a) 27*-1882 758-1882 515-827 *,0-2000

ield t'engt& (M!a) 18*-758 3**-17"3 207-552 380-,,0

!e'cent Elongation (6) 10-32 ,-31 12-,0 5-25

a'dness ( 'inell 3000kg) 8*-388 1,"-*27 137-5"5 210-*20

,.1.9 ALU-INIU-

-luminium silvery white member of the boron group ofchemical elements. has the symbolA and its atomic number is #%. It is not soluble in water under normcircumstances. -luminium is the most abundant metal in the EarthNs crust, and the t

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most abundant element, after o ygen and silicon. It makes up about *6 by weight of tEarthNs solid surface. -luminium is too reactive chemically to occur in nature as a metal. Instead, it is found combined in over 253 different minerals. The chief sourcaluminium is bau ite ore.

-luminium is remarkable for the metalNs low density and for its ability resist corrosion due to the phenomenon of passivation. 0tructural components made faluminium and its alloys are vital to the aerospace industry and are very importanother areas of transportation and building. Its reactive nature makes it useful a catalyst or additive in chemical mi tures, including ammonium nitrate e plosives, enhance blast power.

,.1.: ALU-INIU- NITRIDE -luminium nitride !-l1& is a nitride of aluminium. Its wurt ite phase !w-l1& is a wide band gap !F.2 eB& semiconductor material, giving it potential applicafor deep ultravioletoptoelectronics. -luminium nitride is stable at high temperaturesinert atmospheres and melts at 2*33 RC. In a vacuum, -l1 decomposes at S#*33 RCthe air, surface o idation occurs above 533RC, and even at room temperature, surfo ide layers of #3 nm have been detected. This o ide layer protects the material up t

#%53RC. -bove this temperature bulk o idation occurs. -luminium nitride is stable hydrogen and carbon dio ide atmospheres up to $*3RC.

-pplications of -l1 are

opto electronics,dielectric layers in optical storage media,

electronic substrates, chip carriers where high thermal conductivity is essential,

military applications,

TABLE ,.2 PROPERTIES OF ALU-ONU-

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,.1.; COPPER

Copper is a chemical element with the symbolC& and atomic number 2$.It is a ductile metal, with very high thermal and electrical conductivity. (ure copperrather soft and malleable, and a freshly e posed surface has a reddish orange color. Iused as a thermal conductor, an electrical conductor, a building material, andconstituent of various metal alloys

TABLE ,.3 PROPERTIES OF COPPER

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Mechanical Units of Measure SI/Metric (Imperial)

Densitygm/cc (lb/ft 3) 3.26 (203.5)

Porosity

% (%) 0 (0)

Color gray

Flex ral !trengt"#Pa (lb/in 2x$0 3) 320 ( 6. )

&lastic #o' l sPa (lb/in 2x$0 6) 330 ( .*)

!"ear #o' l sPa (lb/in 2x$0 6)

+ l, #o' l sPa (lb/in 2x$0 6)

Poisson-s atio 0.2 (0.2 )

Com ressi e !trengt" #Pa (lb/in2

x$03

) 2$00 (30 .5)

1ar'nessg/mm 2 $$00

Fract re o g"ness 4C#Pa m $/2 2.6

#axim m se em erat re7C (7F)

Thermal

"ermal Con' cti ity

8/m 7 (+ in/ft 2 "r 7F) $ 09$*0 (: 09$250)

Coefficient of "ermal&x ansion

$0 96 /7C ($0 96 /7F) .5 (2.5)

! ecific 1eat;/ g 7 (+t /lb 7F) 0 (0.$*)


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S+ec * c P"o+e"t e$ o* Co++e"?

U Chemical 0ymbol7 Cu

U -tomic 1umber7 2$

U -tomic +eight7 F%. 8

U >ensity7 *$F3 kg m! %&

U


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,.2.1 SPECIFICATIONS

T-'4E 8.8 0(ECI9IC-TI@1 @9 C@11ECTI1" )@>

0.1@. (-)-I


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2. +I>TH 23mm%. Crank radius 2 mm8. (iston radius #*mm. 4ength of mind section #F*mm

F. Thisckness of


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design, prosthetics, and many more. C-> is also widely used to producecomputer animation forspecial effects in movies,advertising and technical manuals. The modernubiquity and power of computers means that even perfume bottles and shampdispensers are designed using techniques unheard of by engineers of the #$F3s. 'ecauof its enormous economic importance, C-> has been a ma?or driving force for reseain computational geometry, computer graphics !both hardware and software&, anddiscrete differential geometry.

,., ANSYS

-10A0 is a general purpose finite element modeling package for numerically solving

wide variety of mechanical problems. These problems include7 static dynamic structanalysis !both linear and non linear&, heat transfer and fluid problems, as well as acoand electro magnetic problems.

In general, a finite element solution may be broken into the following three stages. Tha general guideline that can be used for setting up any finite element analysis.

#. (reprocessing7 defining the problemG the ma?or steps in preprocessing are g

below7o >efine keypoints lines areas volumes

o >efine element type and material geometric properties

o , 2>, a i symmetric, %>&.

PREPROCESSING? DEFINING THE PROBLE-

#. "ive e ample a Title

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http://en.wikipedia.org/wiki/Prosthesishttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Computational_geometryhttp://en.wikipedia.org/wiki/Computer_graphicshttp://en.wikipedia.org/wiki/Prosthesishttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Computational_geometryhttp://en.wikipedia.org/wiki/Computer_graphics


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/tility esign @ptimi ation

2. Enter initial estimates for variables

To solve an optimi ation problem in -10A0, parameters need to be defined forall design variables.

o 0elect7 /tility efine Jeypoints

(reprocessor V


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(reprocessor V elete...

9or this problem we will use the 'E-


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(reprocessor V isplacement V @

Jeypoints

(in Jeypoint # !ie /P, /A constrained& and constrain Jeypoint 2 in the Adirection.

%. -pply 4oads

0olution V >efine 4oads V -pply V 0tructural V 9orce


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E tracting Information as (arameters7

To perform an optimi ation, we must e tract the required information.

In this problem, we would like to find the ma imum stress in the beam and the volumea result of the width and height variables.

#. >efine the volumeo 0elect "eneral (ostproc V Element Table V >efine Table... V -dd...

o The following window will appear. 9ill it in as shown to obtain the volumof the beam.

1ote that this is the volume of each element. If you were to list thelement table you would get a volume for each element. Therefore, yohave to sum the element values together to obtain the total volume of th beam. 9ollow the instructions below to do this.

o 0elect "eneral (ostproc V Element Table V 0um of Each Item...o - little window will appear notifying you that the tabular sum of each

element table will be calculated. Click N@JN

Aou will obtain a window notifying you that the EBolume is now 83333mm2

2. 0tore the data !Bolume& as a parameter o 0elect /tility


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%. >efine the ma imum stress at the i node of each element in the beamo 0elect "eneral (ostproc V Element Table V >efine Table... V -dd...

o The following window will appear. 9ill it in as shown to obtain th

ma imum stress at the i node of each element and store it as N0ata...

o In the window which appears select N)esults >ataN and N@ther operatio

o In the that appears, fill it in as shown to obtain the ma imum value.

. >efine ma imum stress at the ? node of each element for the beam

o 0elect "eneral (ostproc V Element Table V >efine Table... V -dd...

o 9ill this table as done previously, however make the following changes7

save the data as N0


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o However, select N0


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4.1 PRO= E -ODELS

39


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40


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41


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4.3 ASSE-BLED VIEW

42


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6.1 ANSYS SI-ULATIONS

43


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46


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6.2 FOR-ULAS USED

>E9E4ECTI@1 !y& ! %*8& P !+48 EI&

I '>8

F'ending 0tress !a42+ 2) !$]%gI&&

- ##t 2

6.3 CALCULATIONS

-rea of crank section %.#8 ) 2 2

%.#8 P 2*2 2

#2%#mm2

-rea of piston section %.#8 r 2 2

%.#8 P # 2 2

% %.8mm2

-rea of mid section, a ##t2

## P #32

##33mm2

#2%#^% %.8^##33

2F*8mm2

6., FORGED STEEL

>eflection!y& ! %*8&P!+48 EI&

I '>8

F23P#3 8 F

%%%%.%%mm2

>eflection!y& ! %*8&P! *3P#*8 !2P#3 P%%%%.%%&&

.33#258 mm

48


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'ending stress !a42+ 2)& !$]%gI&

#$*.8 $1 mm 2

6.4 ALU-INU- NITRIDE

>eflection !y& ! %*8& P !+48 EI&

8 2%.%% mm

>eflection!y& ! %*8& P *3P#*8 !2P#3 P8 2%.%%&&

3.333*5# 8mm

'ending 0tress !a42+ 2)& !$]%gI&

#$%.2 1 mm2

49


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6.6 CO-PARISON OF RESULTS

Table no 8. !comparison of results&

(-)-


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CHAPTER 9

CONCLUSION

- detailed study on the material properties of the connecting rod was done to finthe various factors affecting its life this pro?ect investigated weight and cost reduc

opportunities that connecting rods offers. The connecting rod chosen for this pro

belonged to a light weight diesel engine optimi ation was performed to reduce wei

and manufacturing cost. Cost was reduced by changing the material of the current for

steel connecting rod to aluminum nitride. +hile reducing the weight, the static accou

fatigue strength, and the basking load factor were taken into account. The connecting

was optimi ed under 8 different loading conditions. This connecting rod satisfied all

constraints defined and was found to be satisfactory. The optimi ed connecting rod

#36 lighter and connecting rod, in spite of lower strength aluminum nitride compared

the e isting forged steel.

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CHAPTER :

REFERENCE

-f al, -., 2338, ;9atigue 'ehavior and 4ife prediction of 9orged 0teel and (

design and analysis of connecting rod for reduction of weight and cost report

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