design and analysis of camshaft - ijatir

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ISSN 2348–2370

Vol.10,Issue.08,

August-2018,

Pages:0829-0848

Copyright @ 2018 IJATIR. All rights reserved.

Design and Analysis of Camshaft SUDHEER Y

1, RAGHUNATHA REDDY C

2

Abstract: A camshaft is a rotating cylindrical shaft used to

regulate the injection of vaporized fuel in an internal

combustion engine. These are occasionally confused with

the crankshaft of the engine, where the reciprocating

motion of the pistons is converted into rotational energy.

Instead, camshafts are responsible for accurately-timed

fuel injections required by internal combustion engines.

Camshafts have multiple cams on them, which are used to

open valves through either direct contact or pushrods. A

camshaft is directly coupled to the crankshaft, so that the

value openings are timed accordingly. An engine camshaft

can be made from many different types of materials. The

materials used in the camshaft depend upon the quality and

type of engine being manufactured. For most mass-

produced automobiles, chilled cast iron is used. Not only it

is cheap, but child cast iron is also extremely durable and

reliable. This is because cold treating increases the strength

and hardness of any metal that undergoes the process. In

this project, a cam shaft will be designed for a 150cc

engine and modeled through pro/engineer. Present used

material for camshaft is cast iron. In this work, the

camshaft material will be replaced with steel and

aluminum alloy. Structural analysis and model analysis

will be done on cam shaft using cast iron, steel and

aluminum alloy. Comparison will be done for the three

materials to verify the better material for camshaft.

Modeling will be done using pro/Engineer software and

analysis will be done using ANSYS.

Keywords: Numerical Control (NC), RPM, Single

Overhead Camshaft (SOHC), Double Overhead Camshaft

(DOHC).

I. INTRODUCTION

A. Cam Shaft

A cam is a mechanical device used to transmit motion to

a follower by direct contact. The driveris called the cam

and the driven member is called the follower. In a cam

follower pair, the camnormally rotates while the follower

may translate or oscillate. A familiar example is

thecamshaft of an automobile engine, where the cams drive

the push rods (the followers) to openand close the valves in

synchronization with the motion of the pistons. Cams are

used for essentially the same purpose as linkages, that is,

generation of irregular motion. Cams have an advantage

over linkages because cams can be designed for much

tighter motion specifications. In fact, in principle, any

desired motion program can be exactly reproduced by a

cam. Cam design is also, at least in principle, simpler than

linkage design, although, in practice, it can be very

laborious. Automation of cam design using interactive

computing has not, at present, reached the same level of

sophistication as that of linkage design. The disadvantages

of cams are manufacturing expense, poor wear resistance,

and relatively poor high-speed capability. Although

numerical control (NC) machining does cut the cost of cam

manufacture in small lots, costs are still quite high in

comparison with linkages. In large lots, molding or casting

techniques cut cam costs, but not to the extent that

stamping and so forth, can cut linkage costs for similar lot

sizes. Unless roller followers are used, cams wear quickly.

However, roller followers are bulky and require larger

cams, creating size and dynamic problems. In addition, the

bearings in roller followers create their own reliability

problems. The worst problems with cams are, however,

noise and follower bounce at high speeds. As a result, there

is a preoccupation with dynamic optimization in cam

design. Cam design usually requires two steps (from a

geometric point of view):

Synthesis of the motion program for the follower and

Generation of the cam profile.

If the motion program is fully specified throughout the

motion cycle, as is the case, for example, with the stitch

pattern cams in sewing machines, the first step is not

needed. More usually, the motion program is specified

only for portions of the cycle, allowing the synthesis of the

remaining portions for optimal dynamic performance. An

example is the cam controlling the valve opening in an

automotive engine. Here the specification is that the valve

should be fully closed for a specified interval and more or

less fully open for another specified interval. For the

portions of the cycle between those specified, a suitable

program must be synthesized. This can be done, with

varying levels of sophistication, to make the operation of

the cam as smooth as possible. In general, the higher the

level of dynamic performance required, the more difficult

the synthesis process. The second stage of the process,

profile generation, is achieved by kinematic inversion. The

cam is taken as the fixed link and a number of positions of

the follower relative to the cam is constructed. A curve

tangent to the various follower positions is drawn and

becomes the cam profile. If the process is performed

analytically, any level of accuracy can be achieved.

SUDHEER Y, RAGHUNATHA REDDY C

International Journal of Advanced Technology and Innovative Research

Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848

Fig.1. Cam and Camshaft.

Fig.2. CAM Specifications.

Max lift or nose

Flank Opening clearance ramp

Closing clearance ramp

Base circle

Exhaust opening timing figure

Exhaust closing timing figure

Intake opening timing figure

Intake closing timing figure

Intake to exhaust lobe separation

1. Camshaft Operation: The camshaft uses lobes (called

cams) that push against the valves to open them as the

camshaft rotates; springs on the valves return them to their

closed position. This is a critical job, and can have a great

impact on an engine's performance at different speeds.

2. Timing: The relationship between the rotation of the

camshaft and the rotation of the crankshaft is of critical

importance. Since the valves control the flow of air/fuel

mixture intake and exhaust gases, they must be opened and

closed at the appropriate time during the stroke of the

piston. For this reason, the camshaft is connected to the

crankshaft either directly, via a gear mechanism, or

indirectly via a belt or chain called a timing belt or timing

chain.

3. Duration: Duration is the number of crankshaft degrees

of engine rotation during which the valve is off the seat. As

a generality, greater duration results in more horsepower.

The RPM at which peak horsepower occurs is typically

increased as duration increases at the expense of lower rpm

efficiency (torque). Duration can often be confusing

because manufacturers may select any lift point to

advertise a camshaft’s duration and sometimes will

manipulate these numbers. The power and idle

characteristics of a camshaft rated at .006” will be much

differentthan one rated the same at .002”. Many

performance engine builders gauge a race profile’s

aggressiveness by looking at the duration at .020”, .050”

and .200”. The .020” number determines how responsive

the motor will be and how much low end torque the motor

will make. The .050” number is used to estimate where the

poweroccurs, and the .200” number gives an estimate of

the power potential.

4. Lift: The camshaft “lift” is the resultant net rise of the

valve from its seat. The further the valve rises from its seat

the more airflow can be realized, which is generally more

beneficial. Greater lift has some limitations. Firstly, the lift

is limited by the increased proximity of the valve head to

the piston crown and secondly greater effort is required to

move the valve’s springs to higher state of compression.

Increased lift can also be limited by lobe clearance in the

cylinder head construction, so higher lobes may not

necessarily clear the framework of the cylinder head

casing. Higher valve lift can have the same effect as

increased duration where valve overlap is less desirable.

5. Position: Depending on the location of the camshaft, the

cams operate the valves either directly or through a linkage

of pushrods and rockers. Direct operation involves a

simpler mechanism and leads to fewer failures, but

requires the camshaft to be positioned at the top of the

cylinders. In the past when engines were not as reliable as

today this was seen as too much bother, but in modern

gasoline engines the overhead cam system, where the

camshaft is on top of the cylinder head, is quite common.

6. Types of Cams: Cams can be classified based on their

physical shape.

Disk or Plate Cam: The disk (or plate) cam has an

irregular contour to impart a specific motion to the

follower. The follower moves in a plane perpendicular to

the axis of rotation of the camshaft and is held in contact

with the cam by springs or gravity.

Fig.3. Plate or disk cam.

Design and Analysis of Camshaft



Cylindrical Cam: The cylindrical cam has a groove cut

along its cylindrical surface. The roller follows the groove,

and the follower moves in a plane parallel to the axis of

rotation of the cylinder.

Fig.4. Cylindrical cam.

Translating Cam: The translating cam is a contoured or

grooved plate sliding on a guiding surface(s). The follower

may oscillate or reciprocate. The contour or the shape of

the groove is determined by the specified motion of the

follower.

Fig.5. Translating cam.

7. Types of Camshafts: Number of camshafts While today

some cheaper engines depends on a single camshaft per

cylinder bank, which is known as a single overhead

camshaft (SOHC), most modern engine designs (the

overhead-valve or OHV engine being largely obsolete on

passenger vehicles), are driven by a two camshafts per

cylinder bank arrangement (one camshaft for the intake

valves and another for the exhaust valves); such camshaft

arrangement is known as a double or dual overhead cam

(DOHC), thus, a V engine, which has two separate cylinder

banks, and have four camshafts (colloquially known as a

quad-cam engine). The key parts of any camshaft are the

lobes. As the camshaft spins, the lobes open and close the

intake and exhaust valves in time with the motion of the

piston. It turns out that there is a direct relationship

between the shape of the cam lobes and the way the engine

performs in different speed ranges. To understand why this

is the case, imagine that we are running an engine

extremely slowly -- at just 10 or 20 revolutions per minute

(RPM) -- so that it takes the piston a couple of seconds to

complete a cycle. It would be impossible to actually run a

normal engine this slowly, but let's imagine that we could.

At this slow speed, we would want cam lobesshaped so

that:

Just as the piston starts moving downward in the

intake stroke (called top dead center, or TDC), the

intake valve would open. The intake valve would close

right as the piston bottoms out.

The exhaust valve would open right as the piston

bottoms out (called bottom dead center, or BDC) at

the end of the combustion stroke, and would close as

the piston completes the exhaust stroke.

There are several different arrangements of camshafts on

engines.

Single overhead cam (SOHC)

Double overhead cam (DOHC)

Pushrod

Single Overhead Cam: A single overhead cam has one

cam per head. So if it is an inline 4-cylinder or inline 6-

cylinder engine, it will have one cam; if it is a V-6 or V-8,

it will have two cams (one for each head). On single and

double overhead cam engines, the cams are driven by the

crankshaft, via either a belt or chain called the timing belt

or timing chain. These belts and chains need to be replaced

or adjusted at regular intervals. If a timing belt breaks, the

cam will stop spinning and the piston could hit the open

valves.

Double Overhead Cam: A double overhead cam engine

has two cams per head. So inline engines have two cams,

and V engines have four. Usually, double overhead cams

are used on engines with four or more valves per cylinder -

- a single camshaft simply cannot fit enough cam lobes to

actuate all o those valves. The main reason to use double

overhead cams is to allow for more intake and exhaust

valves. More valves, means that intake and exhaust gases

can flow more freely because there are more openings for

them to flow through. This increases the power of the

engine.

II. LITERATURE REVIEW

A. Variable Valve Actuation Introduction

Conventional engines are designed with fixed

mechanically-actuated valves. The position of the

crankshaft and the profile of the camshaft determine the

valve events (i.e, the timing of the opening and closing of

the intake and exhaust valves). Since conventional engines

have valve motion that is mechanically dependent on the

crankshaft position, the valve motion is constant for all

operating conditions. The ideal scheduling of the valve

events, however, differs greatly between different

operating conditions. This represents a significant

compromise in an engine’s design. In standard IC engines,

the compression ratio (set by the engine’s mechanical

design) is also fixed for all engine conditions. The

compression rate is thus limited by the engine condition

with the lowest knock limit. Engine knock is caused by

spontaneous combustion of fuel without a spark (auto-

ignition). For spontaneous combustion to occur, the

temperature and pressure must be sufficiently high.

Therefore the limiting condition occurs at wide open

throttle (WOT) and engine speeds close to redline.




Likewise, lower engine speeds and throttled conditions (the

most common operating conditions when driving a

vehicle) have much less tendency to knock and can with

stand higher compression ratios (hence the potential for

higher efficiency).The most common operating conditions

for IC engines are low engine speeds and moderately

throttled air flow.

Unfortunately, the optimum conditions for the average

IC engine are at WOT and low to moderate engine speeds.

Throttling the intake air creates fluid friction and pumping

losses. High engine speeds create greater mechanical

friction thus reducing the efficiency. Fig1 is an efficiency

map of an engine with the most common operating region

indicated. If the typical operating efficiency of the engine

was improved, then the fuel economy would greatly

increase. The most common use of VVA is load control. A

normal engine uses throttling to control the load of the

engine. When an engine is throttled, the flow separation

created from a throttle body creates fluid losses and the

volumetric efficiency decreases. A major goal of a VVA

engine is to control the amount of air inducted into the

engine without a physical restriction in the flow field. The

torque curve of a conventional engine has a very distinct

peak that generally occurs in the middle of the engine

speed range. The torque produced at low engine speeds is

much less because the incoming mixture of fuel and air is

at a comparatively low velocity. To increase the torque at

low engine speeds, the intake valve should close right after

the piston passes the bottom dead center (BDC) between

the intake and compression strokes. This will effectively

generate a maximum compression ratio for low engine

speeds. Increasing the compression ratio at low engine

speeds essentially pushes the engine closer to a loaded

condition. Conversely at high speeds, the velocity of the

intake mixture is large. Thus the optimum condition is

where the intake valve staysopen longer. The torque curve

comparison between conventional and VVA engines is

shown in Figure.

Fig.6. Efficiency Map of a Typical SI Engine

(Guezennec, 2003).

Fig.7. Torque Curve Comparison.

Another major use of VVA is internal exhaust gas

recirculation (Internal EGR or IEGR). The residual burn

fraction is important for all engine conditions. At low

engine speeds the percent of EGR should be small, because

combustion is already unstable. Moreover, adding

combustion products to the intake charge only reduces the

combustibility. At higher speeds EGR can actually increase

the efficiency and help produce more power. EGR is also

important in limiting the emissions of an engine and

reducing engine knock.

B. Types of Variable Valve Actuation

Engines with VVA can be categorized by their method

of actuation. The three categories are electro hydraulic,

electromechanical and cam-based actuators. The first two

categories are mainly investigated today as potential future

technologies, but they are not technologically ready for use

in a production engine. On the other hand, cam-based

actuation is quickly becoming the standard on many

production engines. There by maximizing their potential

benefits has been the topic of significant research and

development. Cam-based actuators can be further

categorized into variable valve timing(VVT) systems,

discretely-staged cam-profile switching systems, and

continuously variable cam-profile systems. Discretely-

staged cam-profile switching systems generally have two

or possibly three different cam profiles that can be

switched between. Continuously-variable cam-profile

systems have a profile with a constant shape, but the

amplitude can be increased or decreased within a range of

values. Variable valve timing(VVT) is able to change the

valve timings but not the valve lift profiles and durations.

The camshafts can only be advanced or retarded in regard

to its neutral position on the crankshaft. VVT can be

controlled by a hydraulic actuator called a cam phase.

Engines can have a single cam phase (intake cam only) or

two cam phases (both intake and exhaust cams).

C. Discretely-Stage Cam Systems

A dual cam engine has one cam to control the intake and

one cam to control the exhaust valve events. The profile of

the cam determines the timing, the lift and the duration of

the valve opening. Conventionally, these cam profiles

control the valve event throughout the entire engine

operation range. The camshaft would therefore have one




lobe per cylinder. One major branch of VVA, called

discretely staged cam VVA, replaces this standard

camshaft with a camshaft with two lobes per cylinder. The

lobes have drastically different profiles. Figure 3 shows a

picture of a typical discretely staged cam VVA camshaft

and rocker arm. The lift profile of each cam lobe is also

displayed. One profile is very shallow and is used for low

engine loads. The second profile is used when high engine

performance in necessary. This profile is very tall to induct

as much air as possible. Another very similar solution is to

have two separate roller follower arms reading a common

profile, instead of two separate cam profiles. In this

solution the high speed roller arm is much closer to the

camshaft than the low speed arm.

Fig.8. Typical Discretely Staged Cam Setup (Hatano,

1993).

C. Continuously Variable Cam Systems

A step further in VVA development is a continuously

variable cam profile. This is accomplished with a movable

roller follower arm. A normal roller follower does not

move, so the distance away from the camshaft is fixed. An

engine with a movable roller follower arm is able to

control the distance to the camshaft and thus the amount of

valve lift. An illustration of a continuously variable roller

follower arm is presented in Figure. By increasing the

distance from the camshaft, the minimum height on the

cam that will open the valves is increased. This technology

therefore can have an infinite number of possible valve

events. The some of the possible valve lift profiles. As seen

by the graph, the profiles have similar shapes but have

varying amplitudes.

Fig.9. Continuously Variable Roller Follower Arm

(Pierik and Burkhard, 2000).

D. Cam Phasing

Another continuously variable VVA technology, cam

phasing, focuses on cam timing instead of cam profiles.

Cam phasing is a cam based technology that controls the

phase of the camshaft in relation to the crankshaft. An

engine with an intake cam phaser is shown in Figure. The

typical cam phasing engine has a phasing range of about 40

to60 degrees. The valve lift of an engine with cam phasing

is presented in Figure .Although the effect of cam phasing

may seem minor, it is actually one of the most robust

technologies. One of the major goals of VVA is the control

of the air flowing into the cylinders. The two previous

technologies achieved this by controlling the valve lift.

With cam phasing the amount of air ingested into the

combustion chamber is controlled by either early intake

valve opening (EIVO) or late intake valve opening

(LIVO). With early intake valve opening (EIVO) the

intake valves are opened well before top dead center

(TDC) of the crankshaft. The intake valves then close

before the crankshaft reaches bottom dead center (BDC).

The displaced volume is therefore much less than normal.

Late intake valve closing (LIVC) does nearly the exact

opposite. For LIVC the intake valves are opened at about

TDC and then remain open past BDC. At high engine

speeds the intake charge has a large momentum and will

continue to fill the combustion chamber even after BDC.

LIVC increases the volumetric efficiency at high speeds.

Fig.10. Cam Phasing Technology (Moriya, 1996).

Cam phasing of the exhaust cam can also allow for easier

control of exhaust gas recirculation. The timing of the

intake valve opening and closing can alter the effective

compression ratio while also changing the expansion ratio.

Figure 8 illustrates the difference in pressure-volume (p-V)

diagrams between throttling, EIVC and LIVC. The valve

lift profiles for late intake valve opening and early intake

valve closing are shown in Figure . LIVO has the same

effect as the other VVA technologies, namely the profiles

are the same shape as the baseline but with lower

amplitudes. EIVC, however, has an effect unique to cam

phasing. The effect is a high amplitude profile with a short

duration that peaks quickly after TDC.




E. Cam Independent Variable Valve Actuation

Another VVA technology removes the camshaft from the

engine completely. Instead of having the camshaft control

the valve events, they are controlled completely

independently by either electromechanical, hydroelectric or

electromagnetic actuator. The valve timing, lift and

duration can be controlled without limitation. Cylinder

deactivation would also be possible. Without a need for

camshafts, the engine’s overall size could be reduced. This

technology sounds promising, but it is still very

experimental. Because the engine speeds are so high, the

valves have very little time to respond to force inputs. The

valve profiles would look more like a square wave instead

of a gradual increase. This would likely create a great deal

of noise. Another consideration is reliability and durability.

Although it is not perfected yet, independent control of the

valves theoretically has the most potential.

F. Load Control

As previously stated, load control is one the most

significant effects of VVA. Using VVA to control the

engine load significantly reduces the amount of pumping

loses. The overall strategy for cam phasing is shown in

Figure.

Fig.11. Cam Phasing Technology (Moriya, 1996).

G. Optimum Low Load VVA Techniques

Idle and part load conditions do not require a great

deal of intake charge. Ideally this small amount of air

would be inducted with minimal or without any throttling.

Throttling the intake reduces the pressure in the intake

system. This decreased pressure increases the area of the

pumping loop and reduces the net power. The optimum

low speed cam for discretely staged VVA is a low height

and a moderate duration profile. For cam phasing either

LIVO or EIVC should be used. LIVO is more effective for

cold start, and EIVC is more effective for warmed up

engines (Sellnau, 2003). A study on a 1.6 liter 4-cylinder

engine with twin cam phasing was done by Ulrich Kramer

and Patrick Phlips. They found that at 2000 rpm and 2 bar

BMEP the fuel economy was increased by 7.5 percent by

retarding both the intake and exhaust cams. LIVO

increases the volumetric efficiency at low speeds by

closing the intake valve right around BDC. EIVC reduces

the amount of air inducted and eliminates the need for

throttling.

H. Optimum High and Full Load VVA Techniques

At full load the efficient induction of air is the most

important factor. Therefore, the intake cam should have a

very steep and long profile. The profile should be as

aggressive as possible within the knock limit. The valve

overlap should be moderate to high to increase the residual

gas fraction. The intake valves should be closed well after

BDC to increase the volumetric efficiency. Figure shows a

graph of volumetric efficiency versus engine speed for

three different valve timings. It also shows the volumetric

efficiency versus valve lift. As the valve lift is increased,

the volumetric efficiency increases. The maximum

efficiency occurs when the valve lift creates an opening

area equal to the port area.

Fig.12. Optimum Timing and Lift Chart (Heywood,

1988).

Fig.13. Methods of EGR Control (FEV Motortechnik,

2002).

I. Internal Exhaust Gas Recirculation

The thermodynamic efficiency is directly related to the

peak temperature of combustion. Although it seems logical

to increase the temperature of combustion, most of the time




the temperature of combustion is actively sought to be

reduced. Too high of a combustion temperature has several

effects. The first effect is emissions production,

specifically NOx. The concentration of NOx produced by

an engine is a strong function of temperature. Above about

2000 degrees Kelvin the NOx formation increases

dramatically. An increase in temperature from 2000 to

2500 degrees Kelvin increases the NOx reaction rate by

103 times. Even if emissions were not a consideration, the

thermal stresses on the engine create an upper bound for

temperature. Another limiting factor is engine knock. As

the temperature increases, the chance for engine knock also

increases. The combination of higher cylinder wall

temperatures and higher gas temperatures causes the air-

fuel mixture to ignite before the spark plug can ignite the

fuel.

J. Idle and Low Speed EGR Requirements

At idle speed and especially at cold start, EGR actually

inhibits normal combustion. To ensure combustion during

cold start, the ECU increases the fuel by a large amount.

The addition of a non-reactive gas to the combustion

mixture would be counterproductive. The optimum amount

of EGR at idle is normally very small or zero. An engine

can never have zero percent residual gas. From the

physical geometry of the cylinder, the engine has some

residual gases present. Since cylinders have some

clearance volume, not all of the exhaust gases are expelled.

To ensure the residual gas fraction is very small, the valve

overlap is normally zero or negative (there is time between

exhaust closing and intake opening). Figure shows the

major methods of controlling EGR. The top diagram of

Figure corresponds to negative valve overlap.

III. METALS AND ALLOYS

A. Metals

A metal is a material that is typically hard, opaque,

shiny, and has good electrical and thermal conductivity.

Metals are generally malleable that is, they can be

hammered or pressed permanently out of shape without

breaking or cracking as well as fusible and ductile. Metals

in general have high electrical conductivity, high thermal

conductivity and high density. Mechanical properties of

metals include ductility, i.e. their capacity for plastic

deformation. Reversible elastic deformation in metals can

be described by Hooke's Law for restoring forces, where

the stress is linearly proportional to the strain. Forces larger

than the elastic limit, or heat, may cause a permanent

(irreversible) deformation of the object, known as plastic

deformation or plasticity. This irreversible change in

atomic arrangement may occur as a result of:

The action of an applied force (or work). An applied

force may be tensile (pulling) force, compressive

(pushing) force, shear, bending or torsion (twisting)

forces.

A change in temperature (heat). A temperature change

may affect the mobility of the structural defects such

as grain boundaries, point vacancies, line and screw

dislocations, stacking faults and twins in both

crystalline and non-crystalline solids. The movement

or displacement of such mobile defects is thermally

activated, and thus limited by the rate of atomic

diffusion.

B. Alloys

An alloy is a mixture of two or more elements in which

the main component is a metal. Most pure metals are either

too soft, brittle or chemically reactive for practical use.

Combining different ratios of metals as alloys modifies the

properties of pure metals to produce desirable

characteristics. The aim of making alloys is generally to

make them less brittle, harder, resistant to corrosion, or

have a more desirable color and luster of all the metallic

alloys in use today, the alloys of iron make up the largest

proportion both by quantity and commercial value. Iron

alloyed with various proportions of carbon gives low, mid

and high carbon steels, with increasing carbon levels

reducing ductility and toughness. The addition of silicon

will produce cast irons, while the addition of chromium,

nickel and molybdenum to carbon steels results in stainless

steels. other significant metallic alloys are those of

aluminium, titanium, copper and magnesium. Copper

alloys have been known since prehistory bronze gave the

Bronze Age its name and have many applications today,

most importantly in electrical wiring. The alloys of the

other three metals have been developed relatively recently;

due to their chemical reactivity they require electrolytic

extraction processes. The alloys of aluminium, titanium

and magnesium are valued for their high strength-to-

weight ratios; magnesium can also provide electromagnetic

shielding. These materials are ideal for situations where

high strength to weight ratio is more important than

material cost, such as in aerospace and some automotive

applications. Alloys specially designed for highly

demanding applications, such as jet engines, may contain

more than ten elements.

C. Ferrous Metals And Alloys

Ferrous metals and alloys can be divided into iron, and

iron alloys and materials.

Iron: Iron is a soft, silvery metal that is the fourth most

abundant element in the Earth’s crust. Pure iron is

unobtainable by smelting, but small amounts of impurities

can make iron many times stronger than it exists in its pure

form. Iron oxide compounds, when mixed with aluminum

powder, are used to create thermite reactions for welding

and purification processes.

Iron Alloys and Materials: There are a number of

different types of alloys containing iron. Some of the most

important include carbon steels, alloy steels, stainless

steels, tool steels, cast iron, and managing steel.

Carbon steels are steels in which the main alloying

additive is carbon. Mild steel is the most common due

to its low cost. It is neither brittle nor ductile, has

relatively low tensile strength, and is malleable.

Surface hardness can be increased through

http://en.wikipedia.org/wiki/Plastic_deformation


http://en.wikipedia.org/wiki/Hooke%27s_Law

http://en.wikipedia.org/wiki/Stress_%28mechanics%29

http://en.wikipedia.org/wiki/Deformation_%28mechanics%29

http://en.wikipedia.org/wiki/Elastic_limit



http://en.wikipedia.org/wiki/Plasticity_%28physics%29

http://en.wikipedia.org/wiki/Force_%28physics%29

http://en.wikipedia.org/wiki/Work_%28physics%29

http://en.wikipedia.org/wiki/Tensile_strength

http://en.wikipedia.org/wiki/Compressive_strength

http://en.wikipedia.org/wiki/Simple_shear

http://en.wikipedia.org/wiki/Bending

http://en.wikipedia.org/wiki/Torsion_%28mechanics%29

http://en.wikipedia.org/wiki/Crystallographic_defect

http://en.wikipedia.org/wiki/Grain_boundaries

http://en.wikipedia.org/wiki/Dislocation

http://en.wikipedia.org/wiki/Crystalline

http://en.wikipedia.org/wiki/Amorphous_solid

http://en.wikipedia.org/wiki/Activation_energy

http://en.wikipedia.org/wiki/Activation_energy

http://en.wikipedia.org/wiki/Atomic_diffusion

http://en.wikipedia.org/wiki/Atomic_diffusion

http://en.wikipedia.org/wiki/Chemical_element

http://en.wikipedia.org/wiki/Iron

http://en.wikipedia.org/wiki/Silicon

http://en.wikipedia.org/wiki/Chromium

http://en.wikipedia.org/wiki/Nickel

http://en.wikipedia.org/wiki/Molybdenum

http://en.wikipedia.org/wiki/Aluminium

http://en.wikipedia.org/wiki/Titanium

http://en.wikipedia.org/wiki/Copper

http://en.wikipedia.org/wiki/Magnesium

http://en.wikipedia.org/wiki/Bronze

http://en.wikipedia.org/wiki/Bronze_Age

http://en.wikipedia.org/wiki/Electrolysis

http://en.wikipedia.org/wiki/Electromagnetic_shielding

http://en.wikipedia.org/wiki/Electromagnetic_shielding

http://en.wikipedia.org/wiki/Jet_engine




carburizing. High carbon steels have a higher carbon

content which provides a much higher strength at the

cost of ductility.

Alloy steels are steels (iron and carbon) alloyed with

other metals to improve properties. The most common

metals in low alloyed steels are molybdenum,

chromium, and nickel to improve weld ability,

formability, wear resistance, and corrosion resistance.

Stainless steels are steels that contain a minimum of

10% chromium. There are many grades of stainless

steel, but the most common grade used for typical

corrosion resistant applications is type 304, also

known as 18-8. The term 18-8 refers to the amount of

chromium (18%) and nickel (8%) combined with iron

and other elements in smaller quantities. The metal’s

finish is depicted by a number, 3 to 8, with 3 being the

roughest and 8 being a mirror-like finish. Other

specifications to consider include textures and

coatings.

Tool steels are particular steels designed for being

made into tools. They are known for toughness,

resistance to abrasion, ability to hold a cutting edge,

and/or their resistance to deformation at high

temperatures. The three types of tool steel available

are cold work steels used in lower operating

temperature environments, hot work steels used at

elevated temperatures, and high speed steels able to

withstand even higher temperatures giving them the

ability to cut at higher speeds.

Cast iron is an iron alloy derived from pig iron,

alloyed with carbon and silicon. Carbon is added to

the base melt in amounts that exceed the solubility

limits in iron and precipitates out as graphite particles.

Silicon is added to the melt to nucleate the graphite

which optimizes the properties of cast iron. Often

dismissed as a cheap, dirty, brittle metal; cast iron is

getting much more attention and use today because of

its machinability, light weight, strength, wear

resistance, and damping properties.

Merging steels are carbon free iron-nickel alloys with

additions of cobalt, molybdenum, titanium, and

aluminum. The term managing is derived from the

strengthening mechanism, which is transforming the

alloy to marten site with subsequent age hardening.

With yield strengths between 1400 and 2400 MPa,

merging steels belong to the category of ultra-high-

strength materials. The high strength is combined with

excellent toughness properties and weld ability.

D. Materials usage for Camshaft

Camshafts can be made out of several different types of

material. The materials used for the camshaft depends on

the quality and type of engine being manufactured.

Existing Material:

Chilled iron castings: This is a good choice for high

volume production. A chilled iron camshaft has a

resistance against wear because the camshaft lobes have

been chilled, generally making them harder. When making

chilled iron castings, other elements are added to the iron

before casting to make the material more suitable for its

application. Chills can be made of many materials,

including iron, copper, bronze, aluminum, graphite, and

silicon carbide. Other sand materials with higher densities,

thermal conductivity or thermal capacity can also be used

as a chill. For example, chromate sand or zircon sand can

be used when molding with silica sand.

Implemented Material: Alloy Steel

Alloy Steel: Alloy steels are steels containing elements

such as chromium, cobalt, nickel,etc. Alloy steels comprise

a wide range of steels having compositions that exceed the

limitations of Si, Va, Cr, Ni, Mo, Mn, B and C allocated

for carbon steels.

IV. INTRODUCTION TO CAD/CAM

A. Computer Aided Design (CAD)

Computer Aided Design (CAD) is the use of wide range

of computer based tools that assist engineering, architects

and other design professionals in their design activities. It

is the main geometry authoring tool within the product life

cycle management process and involves both software and

sometimes special purpose hardware. Current packages

range from 2D vector based drafting systems to 3D

parametric surface and solid design models.

Introduction: CAD is used to design and develop

products, which can be goods used by end consumers or

intermediate goods used in other products. Cadis also

extensively used in the design of tools and machinery used

in the manufacturer of components. Cadis also used in the

drafting and design of all types of buildings, from small

residential types(house) to the largest commercial and

industrial types. CAD is used thought the engineering

process from the conceptual design and layout, through

detailed engineering and analysis of components to

definition of manufacturing methods.

B. Introduction To PRO/E:

PRO/E is the industry’s de facto standard 3D mechanical

design suit. It is the world’s leading CAD/CAM /CAE

software, gives a broad range of integrated solutions to

cover all aspects of product design and manufacturing.

Much of its success can be attributed to its technology

which spurs its customer’s to more quickly and

consistently innovate a new robust, parametric, feature

based model. Because that PRO/E is unmatched in this

field, in all processes, in all countries, in all kind of

companies along the supply chains.PRO/E is also the

perfect solution for the manufacturing enterprise, with

associative applications, robust responsiveness and web

connectivity that make it the ideal flexible engineering

solution to accelerate innovations. PRO/E provides easy to

use solution tailored to the needs of small medium sized

enterprises as well as large industrial corporations in all

industries, consumer goods, fabrications and assembly.

Electrical and electronics goods, automotive, aerospace,

shipbuilding and plant design. It is user friendly solid and

surface modeling can be done easily.




Advantages of PRO/E:

It is much faster and more accurate.

Once a design is completed. 2D and 3D views are

readily obtainable.

The ability to changes in late design process is

possible.

It provides a very accurate representation of model

specifying all other dimensions hidden geometry etc.

It is user friendly both solid and surface modeling can

be done.

It provides a greater flexibility for change. For

example if we like to change the dimensions of our

model, all the related dimensions in design assembly,

manufacturing etc. will automatically change.

It provides clear 3D models, which are easy to

visualize and understand.

PRO/E provides easy assembly of the individual parts

or models created it also decreases the time required

for the assembly to a large extent.

C. PRO/E Interface The main modules are:

Sketcher

Part Design

Assembly

Drafting

Sheet metal

Sketcher: Pro/E sketcher tools initially drafts a rough

sketch following the shape of the profile. The objects

created are converted into a proper sketch by applying

geometric constraints and dimensional constraints. These

constraints refine the sketch according to a rule. Adding

parametric dimensions further control the shape and size of

the feature. Line, rectangle, palette, constrain, dimension

modification, and text etc., are used as one of the feature

creation tools to convert the sketcher entity into a part

feature.

Part Design: The Pro/E is a 3D parametric solid modeler

with both part and assembly modeling abilities. You can

use Pro/E to model simple parts and then combine them

into more complex assemblies. With Pro/E, you design a

part by sketching its component shapes and defining their

size, shape, and inter relationships. By successively

creating these shapes, called features, you can construct the

part. The general modeling process-

Planning concept of designing

Creation of base feature

Completion of other features

Analyzing the part design

Modifying the design as necessary

Assembly Design: Pro-E assembly design gives the user

the ability to design with user controlled associability. Pro-

E builds individual parts and subassemblies into an

assembly in a hierarchical manner according to the

relationships defined by constraints. As in part modeling,

the parametric relationships allow you to quickly update an

entire assembly based on a change in one of its parts.

Top-down Assembly: In the top-down approach of

assembling of components , the components are

created in the assembly for itself, and the assembled,

using the assembly constraints .The parts you create in

assembly mode are saved as, part files.

Bottom-up Assembly: In this method, the parts

created in part mode are assembled in the assembly

mode, using assembly constraints. Assembly files

created in this method, occupy less disc space as they

contain only the information related to the assembling

of components. However , if any of the assembly

components is moved from its original location, the

assembly will not open.

The general assembly process-

Layout the assembly

Based on design follow either top down or bottom up

Analyze the assembly

Modifying the assembly

Drafting: Drawings and documentation are the true

products of design because they guide the manufacture of a

mechanical device. Pro-E automatically generate

associative drafting from 3D mechanical designers and

assemblies. Associability of the drawings to the 3D master

representation enables to work concurrently on designs and

drawings. Pro-E enriches Generative Drafting with both

integrated 2D interactive functionality and a productive

environment for drawings dress-up and annotation.

Sheet Metal: Thin sheets of metal that have a thickness

between 0.006 inches and 0.249 inches are generally called

sheet metals. They are one of the fundamental forms used

in metal works. They can be cut and bent into a variety of

shapes

D. Features Of PRO/E

Pro/Engineer is a one stop store for any manufacturing

industry. It offers effective features, incorporated for a

wide variety or purpose. Some of the important features

are as follows:

Simple and powerful tools

Parametric Design

Feature-Based Approach

Parent Child Relationship

Associative and Model Centric

Simple and Powerful Tools: Pro/Engineer tools are user

friendly. Although the execution of any operation using the

tools is simple, the tools can create a highly complex

model.

Parametric Design: Pro/Engineer designs are parametric.

The term “Parametric” means that design operations that

are captured, can be stored as they take place. They can be

used effectively in the future for modifying and editing the

design. These types of modeling help in faster and easier




modifications of design. If the model is parametric and

related properly, a change in one value, automatically edits

the related values.

Feature-Based Approach: Features are the basic building

blocks required to create an object. Pro/Engineer wild fire

models are based on a series of features. Each feature

builds upon the previous feature, to create the model (only

one single feature can be modified at a time). Each feature

may appear simple, individually, but collectively forms a

complex part and assemblies.

Parent Child Relationship: The parent child relationship

is a powerful way to capture design internet in a model.

This relationship naturally occurs among features, during

the modeling process. When we create a new feature, the

existing features that are referenced, become parent to the

new feature.

Associative and Model Centric: Pro/Engineer wild fire

drawings are model centric. This means that Pro/ Engineer

models that are represented in assembly or drawings are

associative. If changes are made in one module, these will

automatically get updated in the referenced module.

E. General Operations

Start with a Sketch: Use the Sketcher to freehand a

sketch, and dimension an "outline" of Curves. You can

then sweep the sketch using Extruded Body or Revolved

Body to create a solid or sheet body. You can later refine

the sketch to precisely represent the object of interest by

editing the dimensions and by creating relationships

between geometric objects. Editing a dimension of the

sketch not only modifies the geometry of the sketch, but

also the body created from the sketch.

Creating and Editing Features: Feature modeling lets

you create features such as holes, extrudes and revolves on

a model. You can then directly edit the dimensions of the

feature and locate the feature by dimensions. For example,

a Hole is defined by its diameter and length. You can

directly edit all of these parameters by entering new values.

Associatively: Associatively is a term that is used to

indicate geometric relationships between individual

portions of a model. These relationships are established as

the designer uses various functions for model creation. In

an associative model, constraints and relationships are

captured automatically as the model is developed. For

example, in an associative model, a through hole is

associated with the faces that the hole penetrates. If the

model is later changed so that one or both of those faces

moves, the hole updates automatically due to its

association with the faces. See Introduction to Feature

Modeling for additional details.

Positioning a Feature: Within Modeling, you can position

a feature relative to the geometry on your model using

Positioning Methods, where you position dimensions. The

feature is then associated with that geometry and will

maintain those associations whenever you edit the model.

You can also edit the position of the feature by changing

the values of the positioning dimensions.

Reference Features: You can create reference features,

such as Datum Planes, Datum Axes and Datum CSYS,

which you can use as reference geometry when needed, or

as construction devices for other features. Any feature

created using a reference feature is associated to that

reference feature and retains that association during edits to

the model. You can use a datum plane as a reference plane

in constructing sketches, creating features, and positioning

features. You can use a datum axis to create datum planes,

to place items concentrically, or to create radial patterns.

Expressions: The Expressions tool lets you incorporate

your requirements and design restrictions by defining

mathematical relationships between different parts of the

design. For example, you can define the height of a

extrudes as three times its diameter, so that when the

diameter changes, the height changes also.

Undo: The design can be returned to a previous state any

number of times using the Undo function. It do not make

the designers to take a great deal of time making sure each

operation is absolutely correct, because a mistake can be

easily undone. This freedom to easily change the model

lets you cease worrying about getting it wrong, and frees

you to explore more possibilities to get it right.

E. Model Is Drawn

Modeling process of Camshaft Parts:

Fig.14.First CAM Preparation.

Fig.15. Second CAM Preparation.




Fig.16. Total CAM Preparation.

Fig.17. Exploded view of bearing assembly.

Fig.18. An Exploded view of total CAM shaft.

V. FINITE ELEMENT METHOD / ANALYSIS

(FEM/A)

The finite element method is numerical analysis technique

for obtaining approximate solutions to a wide variety of

engineering problems. Because of its diversity and

flexibility as an analysis tool, it is receiving much attention

in almost every industry. In more and more engineering

situations today, we find that it is necessary to obtain

approximate solutions to problem rather than exact closed

form solution. It is not possible to obtain analytical

mathematical solutions for many engineering problems.

The finite element method has become a powerful tool for

the numerical solutions of a wide range of engineering

problems. It has been developed simultaneously with the

increasing use of the high- speed electronic digital

computers and with the growing emphasis on numerical

methods for engineering analysis. This method started as a

generalization of the structural idea to some problems of

elastic continuum problem, started in terms of different

equations. The basic idea in the Finite Element is to find

the solution of complicated problem with relatively easy

way. The Finite Element Method has been a powerful tool

for the numerical solution of a wide range of engineering

problems. Applications range from deformation and stress

analysis of automotive, aircraft, building, defence, and

missile and bridge structures to the field of analysis of

dynamics, stability, fracture mechanics, heat flux, fluid

flow, magnetic flux, seepage and other flow problems.

With the advances in computer technology and CAD

systems, complex problems can be modeled with relative

ease. Several alternate configurations can be tried out on a

computer before the first prototype is built.

The basics in engineering field are must to idealize the

given structure for the required behaviour. The proven

knowledge in the typical problem area, modeling

techniques, data transfer and integration, computational

aspects of the Finite Element Method is essential. In the

Finite Element Method the solution region is considered as

built up many small, interconnected sub regions called

finite elements. Most often it is not possible to ascertain

the behaviour of complex continuous systems without

some sort of approximations. For simple members like

uniform beams, plates etc., classical solutions like machine

tool frames, pressure vessels, automobile bodies, ships, air

craft structures, domes etc., need some approximate

treatment to arrive at their behaviour, be it static

deformation, dynamic properties or heat conducting

property. Indeed these are continuous systems with their

mass and elasticity being continuously distributed. To

overcome this, engineers and mathematicians have from

time to time proposed complex structure is defined using a

finite number of well defined components. Such systems

are then regarded as discrete systems. The discretization

method could be finite difference approximation, various

residual procedures etc.

A. Historical Background

The Finite Element Method as known today has been

presented in 1956 by Turner, Clough, Martin and Topp.

The name Finite Element Method was first coined by

R.W.Clough. Important early contributions were those of

J.H.Argyris and O.C.Zienckiwiez and Y.K.Cheung. Since

the early 1960’s, a large amount of research has been

devoted to the technique, and a very large number of

publications on the Finite Element Method is now

available. The Finite Element Method was initially

developed for structural mechanics but later on it was

applied to heat transfer, fracture mechanics, flow and

coupled field problems.




B. General Applicability Of The Method

Although the method has been extensively used in the

field of the structural, mechanics, it has been successfully

applied to solve several other type of engineering problems

like heat conduction, fluid dynamics, seepage flow and

electric and magnetic fields. These applications prompted

mathematicians to use this technique for the solution of the

complicated boundary value and other problems. In fact, it

has been established that the method can be used for the

numerical solution of ordinary and partial differential

equations, the general applicability of the finite element

method can be seen by observing the strong similarities

that exist between various types of engineering problems.

C. Need of the Finite Element Method

To predict the behaviour of structure the designer adopts

three tools such as analytical, Experimental and Numerical

methods. The analytical method is used for the regular

sections of known geometric entities or primitives where

the component geometry is expressed mathematically. The

solution obtained through analytical method is exact and

takes less time. This method cannot be used for irregular

sections and the shapes which required very complex

mathematical equations. On the other hand the

experimental method is used for finding the unknown

parameters of interest. But the experimentation requires

testing equipment and a specimen for each behaviour of

requirement. This in turn, requires a high initial investment

to procure the equipment and to prepare the specimens.

The solution obtained is exact by the time consumed to

find the result and during preparation of specimens also

more. There are many numerical schemes such as Finite

difference methods, Finite Element Method, Boundary

element and volume method, Finite strip and volume

method and Boundary integral methods etc., are used to

estimate the approximate solutions of acceptably tolerance.

The Finite Element Method is so popular because of

it’sfavourably towards use of digital computers. The Finite

Element Method predicts the component behaviour at

desired accuracy of any complex and irregular geometry at

least price.

D. Design Considerations

Engineering Design is the process of devising a system

component or process to meet desired needs. It is the

decision-making process (often iterative) in which the

basic sciences, mathematics and engineering sciences are

applied to convert resources optimally to meet a stated

objective. Among the fundamental elements of the design

process are the establishment of objectives and criteria,

syntheses, analysis, construction, testing and evaluation.

The typical design criteria that should be satisfied for a

particular structure are listed below.

Cost

Reliability

Weight

Ease of operation and maintenance

Appearance

Compatibility

Safety features

Noise level

Effectiveness

Durability

Feasibility

Acceptance

During the design process the structure stability is judged

by means of analysis. The analysis may be Kinematic,

Dynamic and Finite Element Analysis. The design may be

categorized as rigid basis, strength based in which the

deflections and stresses induced should be less than

allowably values. In the case of critical speed based design

the system natural frequencies are estimated. Then the

system is operated either above or below the estimated

natural frequencie

E. The Process Of Finite Element Method

Fig.19. Flow chart.




The Finite Element Method is used to solve physical

problems in engineering analysis and design. Flow chart

summarizes the process of Finite Element Analysis. The

physical problem typically involves an actual structure or

structural component subjected to certain loads. The

idealization of the physical problem to a mathematical

model requires certain assumptions that together lead to

differential equations governing the mathematical model.

The Finite Element Analysis solves the Mathematical

model, which describes the physical problem. The FEM is

a numerical procedure; it is necessary to assess the solution

accuracy. If the accuracy criteria are not met, the numerical

solutions have to be repeated with refined solution

parameters until a sufficient accuracy is reached.

E. Procedure For Ansys

Static analysis is used to determine the displacements

stresses, stains and forces in structures or components due

to loads that do not induce significant inertia and damping

effects. Steady loading in response conditions are assumed.

The kinds of loading that can be applied in a static analysis

include externally applied forces and pressures, steady

state inertial forces such as gravity or rotational velocity

imposed(non-zero)displacements, temperatures (for

thermal strain). A static analysis can be either linear or non

linear. In our present work we consider linear static

analysis. The procedure for static analysis consists of these

main steps

Building the model

Obtaining the solution

Reviewing the results.

Build the Model: In this step we specify the job name and

analysis title use PREP7 to define the element types,

element real constants, material properties and model

geometry element type both linear and nonlinear

structural elements are allowed. The ANSYS elements

library contains over 80 different element types. A unique

number and prefix identify each element type. E.g. BEAM

94, PLANE 71, SOLID 96 and PIPE 16.

Material Properties: Young’s Modulus (EX) must be

defined for a static analysis. If we plan to apply inertia

loads (such as gravity) we define mass properties such as

density (DENS). Similarly if we plan to apply thermal

loads (temperatures) we define coefficient of thermal

expansion (ALPX).

Geometrical Definitions: There are four different

geometric entities in pre processor namely key points,

lines, area and volumes. These entities can be used to

obtain the geometric representation of the structure. All the

entities are independent of other and have unique

identification labels.

Model Generations: Two different methods are used to

generate a model:

Direct generation.

Solid modeling

With solid modeling we can describe the geometric

boundaries of the model, establish controls over the size

and desired shape of the elements and then instruct

ANSYS program to generate all the nodes and elements

automatically. By contrast, with the direct generation

method, we determine the location of every node and size

shape and connectivity of every element prior to defining

these entities in the ANSYS model. Although, some

automatic data generation is possible (by using commands

such as FILL, NGEN, EGEN etc.) the direct generation

method essentially a hands on numerical method that

requires us to keep track of all the node numbers as we

develop the finite element mesh. This detailed book

keeping can become difficult for large models, giving

scope for modeling errors. Solid modeling is usually more

powerful and versatile than direct generation and is

commonly preferred method of generating a model.

Mesh Generation: In the finite element analysis the basic

concept is to analyze the structure, which is an assemblage

of discrete pieces called elements, which are connected,

together at a finite number of points called Nodes. Loading

boundary conditions are then applied to these elements and

nodes. A network of these elements is known as mesh

Finite Element Generation: The maximum amount of

time in a finite element analysis is spent on generating

elements and nodal data. Pre-processor allows the user to

generate nodes and elements automatically at the same

time allowing control over size and number of elements.

There are various types of elements that can be mapped or

generated on various geometric entities. The elements

developed by various automatic element generation

capabilities of pre processor can be checked element

characteristics that may need to be verified before the finite

element analysis for connectivity, distortion-index etc.

Generally, automatic mesh generating capabilities of pre

processor are used rather than defining the nodes

individually. If required nodes can be defined easily by

defining the allocations or by translating the existing

nodes. Also on one can plot, delete, or search nodes.

Boundary Conditions And Loading: After completion of

the finite element model it has to constrain and load has to

be applied to the model. User can define constraints and

loads in various ways. All constraints and loads are

assigned set ID. This helps the user to keep track of load

cases.

Model Display: During the construction and verification

stages of the model it may be necessary to view it from

different angles. It is useful to rotate the model with

respect to the global system and view it from different

angles. Pre processor offers these capabilities. By

windowing feature pre processor allows the user to enlarge

a specific area of the model for clarity and details. Pre

processor also provides features like smoothness, scaling,

regions, active set, etc., for efficient modal viewing and

editing.




Material Defections: All elements are defined by nodes,

which have only their location defined. In the case of plate

and shell elements there is no indication of thickness. This

thickness can be given as element property. Property tables

for a particular property set 1-D have to be input. Different

types of elements have different properties for e.g.

Beams: Cross sectional area, moment of inertia etc.

Shell: Thickness

Springs: Stiffness

Solids: None

The user also needs to define material properties of the

elements. For linear static analysis, modules of elasticity

and Poisson’s ratio need to be provided. For heat transfer,

coefficient of thermal expansion, densities etc. are

required. They can be given to the elements by the material

property set to 1-D.

Solution: The solution phase deals with the solution of the

problem according to the problem definitions. All the

tedious work of formulating and assembling of matrices

are done by the computer and finally displacements are

stress values are given as output. Some of the capabilities

of the ANSYS are linear static analysis, non linear static

analysis, transient dynamic analysis, etc.

Post- Processor: It is a powerful user- friendly post-

processing program using interactive color graphics. It has

extensive plotting features for displaying the results

obtained from the finite element analysis. One picture of

the analysis results (i.e. the results in a visual form) can

often reveal in seconds what would take an engineer hour

to assess from a numerical output, say in tabular form. The

engineer may also see the important aspects of the results

that could be easily missed in a stack of numerical data.

Employing state of art image enhancement techniques,

facilities viewing of Contours of stresses, displacements,

temperatures, etc. The phases that are involved in the post

processor

Deform geometric plots

Animated deformed shapes

Time-history plots

Solid sectioning

Hidden line plot

Light source shaded plot

Boundary line plot etc.

The entire range of post processing options of different

types of analysis can be accessed through the

command/menu mode there by giving the user added

flexibility and convenience.

F. Thermal Analysis

A thermal analysis calculates the temperature distribution

and related thermal quantities in brake disc. Typical

thermal quantities are:

The temperature distribution

The amount of heat lost or gained

Thermal fluxes

Types of Thermal Analysis:

Steady state thermal analysis.

Transient thermal analysis.

A steady state thermal analysis determines the

temperature distribution and other thermal quantities

under steady state loading conditions. A steady state

loading condition is a situation where heat storage

effects varying over a period of time can be ignored.

A transient thermal analysis determines the temperature

distribution and other thermal quantities under

conditions that varying over a period of time. The

ANSYS/ metaphysics, ANSYS/mechanical, ANSYS/

thermal, and ANSYS/FLOTRAN products support

transient thermal analysis. Transient thermal analysis

determined temperature and other thermal quantities

that vary over time. A Engineers commonly used

temperature that a transient thermal analysis for thermal

stress evaluation. Many heat transfer applications-heat

treatment problems, nozzles, engine block, piping

system, pressure vessels, etc. involve transient thermal

analyses.

A transient thermal analysis follows basically the same

procedure as a stead state thermal analysis. The main

difference is that most applied loads in a transient analysis

are functions of time.

Planning for Analysis: In this step a compromise between

the computer time and accuracy of the analysis is made.

The various parameters set in analysis are given below:

Thermal modeling

Analysis type. Thermal h-method.

Steady state or Transient? Transient

Thermal or Structural? Thermal

Properties of the material? Isotropic

Objective of analysis- to find out the temperature

distribution in the brake disc when the process of

braking is done.

G. Structural Analysis Structural analysis is the most common application of the

finite element analysis. The term structural implies civil

engineering structure such as bridge and building, but also

naval, aeronautical and mechanical structure such as ship

hulls, aircraft bodies and machine housing as well as

mechanical components such as piston, machine parts and

tools.

Types of Structural Analysis: The seven types of

structural analysis in ANSYS. One can perform the

following types of structural analysis. Each of these

analysis types are discussed as follows:

Static analysis

Modal analysis

Harmonic analysis

Transient dynamic analysis

Spectrum analysis

Buckling analysis

Explicit dynamic analysis




Static Structural Analysis: A static analysis calculates the

effects of steady loading conditions on a structure, while

ignoring inertia and damping effects such as those caused

by time varying loads. A static analysis can, however

include steady inertia loads (such as gravity and rotational

velocity), and time varying loads that can be approximated

as static equivalent loads (such as static equivalent wind

and seismic loads).

Model Analysis: In this type of analysis we determine

the vibration characteristics and also used to calculate

the natural frequencies and mode shapes of a structure.

Different mode extraction methods are available.

Harmonic Analysis: In this analysis we determine the

response of structure to harmonically time varying

loads and also used to determine the response of a

structure to harmonically time varying loads.

Transient Dynamic Analysis: This is used to

determine the response of a structure to arbitrarily

time-varying loads. All nonlinearities mentioned under

Static Analysis above are allowed.

Spectrum Analysis: An extension of the model

analysis, used to calculate stresses and strains due to a

response spectrum or a PSD input (random

vibrations).

Buckling Analysis: In this analysis we can determine

the buckling loads and also buckling shape and also

used to calculate the buckling loads and determine the

buckling mode shape. Both linear (eigen value)

buckling and nonlinear buckling analyses are possible.

Explicit Dynamic Analysis: Explicit dynamic

analysis is used to calculate fast solutions for large

deformation dynamics and complex contact problems.

Finite Element Program Packages: The general

applicability of finite element method makes it a powerful

and versatile tool for a wide range of problems. Hence a

number of computer program packages have been

developed for easy solution of a variety of structural and

solid mechanics problems. Some of the programs have

been developed in such a general manner that the same

program can be used for the solution of problems

belonging to different branches of engineering with little or

no modifications. Many of these packages represent large

programs, which can be used for solving real complex

problems. For example the NASTRAN (National

Aeronautics and Space Administration Structural Analysis)

program package contains about 1, 50,000 Fortran

statements and can be used to analyze physical problems of

practically any size, such as a complete aircraft or an

automobile structure. The availability of the super-

computers has made a strong impact on the finite element

technology. In order to realize a full potential of these

supercomputers in finite element competition, special

parallel numerical algorithms, program strategies and

programming languages are being developed.

Procedure:

Importing the Model: In this step the PRO/E model is to

be imported into ANSYS workbench as follows: In utility

menu file option and selecting import external geometry

and open file and click on generate. To enter into

simulation module click on project tab and click on new

simulation.

Defining Material Properties:

To define material properties for the analysis,

following steps are used

The main menu is chosen select model and click on

corresponding bodies in tree and then create new

material enter the values again select simulation tab

and select material

Defining Element Type:

To define type of element for the analysis, these steps

are to be followed:

Chose the main menu select type of contacts and then

click on mesh-right click-insert method

Method - Tetrahedrons

Algorithm - Patch Conforming

Element Mid side Nodes – Kept

Meshing the Model:

To perform the meshing of the model these steps are

to be followed:

Chose the main menu click on mesh- right click- insert

sizing and then select geometry enter element size and

click on edge behavior curvy proximity refinement

and then right click generate mesh.

Fig.20. Mesh Generation of the Modal.

Boundary Conditions And Pressure: To apply the

boundary conditions on the model these steps are to be

followed: The main menu is chosen click on new analysis

tab select static structural click on face and then select face

of the geometry-right click- insert-fixed support. The main

menu is chosen select pressure and click on face of

geometry- right click – insert – pressure.




Fig.21. Fixed support.

Fig.22. Presser application.

Case: 1

Structural Steel:

Fig.23. Total deformation.

Fig.24. Equivalents stress.

Chilled Cast Iron:

Fig.25. Total deformation.

Fig.26. Equivalents stress.




TABLE I: Comparison Of Stress Results Of Different

Materials

H. Model Analysis

Model analysis is the study of the dynamic properties

of structures under vibrational excitation. Model analysis is

the field of measuring and analyzing the dynamic response

of structures and or fluids when during excitation.

Examples would include measuring the vibration of a car's

body when it is attached to an electromagnetic shaker, or

the noise pattern in a room when excited by a loudspeaker.

Model Analysis Results:

Structural Steel:

Fig.27. Mode 1 and Frequency 13.77 Hz.




Chilled Cast Iron:








I. Thermal Analysis

Structural Steel

Fig.35. Temperature in put.

Fig.36. Heat convection.

Fig.37. Temperature.




Fig.38 Total .heat flux

Chilled Cast Iron:

Fig.39. Temperature.

Fig.40.Total heat flux.

J. Graphs

According to results of static structural analysis graphs

are plotted for the Chilled cast iron, Steel Alloy, Graphs

are plotted for the Von-mises stress and Deformation.

Structural Steel:

Fig.41. Graph for Deformation Vs Von mises stress

Chilled Cast Iron:

Fig.42. Graph for Deformation Vs Von misses stress.

VI. RESULTS AND DISCUSSION

From Static structural analysis the values obtained for

the materials Chilled cast iron, Steel alloy are Tabulated

below.

For Chilled Cast Iron:

TABLE II: Static Structural Analysis Result For

Chilled Cast Iron

For Steel Alloy:

TABLE III: Static Structural Analysis Result For Steel

Alloy

VII. CONCLUSION

Results obtained from Static structural analysis we can

say that the material Steel alloy is also applicable for

manufacturing the Camshaft. As the Total deformation and




Von-mises stress values of camshaft is less compared with

Chilled cast iron. This Result is applicable for the further

analysis as well as for the manufacturing processes can be

decided from results. Another application of this analysis is

material selection related to camshaft which becomes

easier for the manufacturer.

VIII. REFERENCES

[1]G.K. Matthew., D. Tesar.(1976), Cam system design:

The dynamic synthesis and analysis of the one degree of

freedom model, Mechanism and Machine Theory, Volume

11, Issue 4, Pages 247-257.

[2]M.O.M Osman., B.M Bahgat., Mohsen Osman., (1987),

Dynamic analysis of a cam mechanism with bearing

clearances, Mechanism and Machine Theory, Volume 22,

Issue 4, Pages 303-314.

[3]Robert L Norton.( 1988), Effect of manufacturing

method on dynamic performance of cams— An

experimental study. part I—eccentric cams, Mechanism

and Machine Theory, Volume 23, Issue 3, Pages 191-199.

[4]Alberto Cardona., Michel Géradin.(1993), Kinematic

and dynamic analysis of mechanisms with cams, Computer

Methods in Applied Mechanics and Engineering, Volume

103, Issues 1–2, Pages 115-134.

[5]G. Wang., D. Taylor., B. Bouquin, J. Devlukia., A.

Ciepalowicz. (2000), Prediction of fatigue failure in a

camshaft using the crack modeling method, Engineering

Failure Analysis, Volume 7, Issue 3, Pages 189-197.

[6]Zubeck, M. and Marlow, R. (2003), Local-Global

Finite-Element Analysis for Cam Cover Noise Reduction,

SAE Technical Paper ,01-1725, doi: 10.4271/2003-01-

1725.

[7]De Abreu Duque, P., de Souza, M., Savoy, J., and

Valentina, G. (2011), Analysis of the Contact Pressure

between Cams and Roller Followers in Assembled

Camshafts, SAE Technical Paper 2011-36-0247,

doi:10.4271/2011-36-0247.

[8]R.S. Khurmi and J.K. Gupta. “Machine Design”, a

division of S. Chand & Co. Ltd. p.514-515.

[9]Magnus Hellstr¨om. “Engine Speed Based Estimation of

the Indicated Engine Torque”, Reg nr: LiTH-ISY-EX-

3569-2005 16th February 2005.

[10]R.˙Ipek, B. Selcuk ,“The dry wear profile of camshaft”

Journal of Materials Processing Technology 168 (2005)

373–376

[11]W.A. Glaeser and S.J. Shaffer, Battelle Laboratories

“contact fatigue”, ASM Handbook, Volume 19: Fatigue

and Fracture, ASM Handbook Committee, p 331-336

[12]“Physics Digest- Part 1”, Navneet Publication.

design and analysis of camshaft - ijatir

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