design and analysis of camshaft - ijatir
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ISSN 2348–2370
Vol.10,Issue.08,
August-2018,
Pages:0829-0848
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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
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
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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
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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.
Design and Analysis of Camshaft
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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.
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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.
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
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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 non- linear
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.
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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
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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.
Fig.28. Mode 2 and Frequency 28.712 Hz.
Fig.29. Mode 3 and Frequency 33.33 Hz.
Fig.30. Mode 4 and Frequency 45.62 Hz.
Chilled Cast Iron:
Fig.31. Mode 1 and Frequency 11.08 Hz.
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
Fig.32. Mode 2 and Frequency 22.86 Hz.
Fig.33. Mode 3 and Frequency 31.48 Hz.
Fig.34. Mode 3 and Frequency 45.202 Hz.
I. Thermal Analysis
Structural Steel
Fig.35. Temperature in put.
Fig.36. Heat convection.
Fig.37. Temperature.
Design and Analysis of Camshaft
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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
SUDHEER Y, RAGHUNATHA REDDY C
International Journal of Advanced Technology and Innovative Research
Volume. 10, IssueNo.08, August-2018, Pages: 0829-0848
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
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[2]M.O.M Osman., B.M Bahgat., Mohsen Osman., (1987),
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[3]Robert L Norton.( 1988), Effect of manufacturing
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[7]De Abreu Duque, P., de Souza, M., Savoy, J., and
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[9]Magnus Hellstr¨om. “Engine Speed Based Estimation of
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[10]R.˙Ipek, B. Selcuk ,“The dry wear profile of camshaft”
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