MODELING AND THERMAL ANALYSIS OF DISC BRAKE

ABSTRACT
The brake drum is a critical component that experiences high temperatures and develop
thermal stresses during application of brakes. In addition, the application of shoe pressure gives
rise to mechanical loads. So the analysis takes into account both the thermal stresses and
mechanical stresses together. Since theanalytical solution is not possible due to combination of
loads and varying of contour of the brake drum, it isnecessary to carry out finite element approach
in order to evaluate the exact stress distribution and make surethat the stress values are well
below the allowable limits.
In this project Drum modelled by using cad tool creo-8, then it is imported into cae tool to
analysis, in this case the model was checked by real time boundary conditions both static and
thermal, with two materials by this we can find out deformation, stress, safety factor, and heat
flux and total temperature distributions, from all the results we can find which material is most
suitable for the object
Tools were used:

Cad tool: creo-8

Cae tool: Ansys

 CHAPTER 1

INTRODUCTION

A disc brake is a wheel brake that slows rotation of the wheel by the friction caused by
pushing brake pads against a brake disc with a set of calipers. The brake disc (or rotor in
American English) is usually made of cast iron, but may in some cases be made of composites
such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel
and/or the axle. To stop the wheel, friction material in the form of brake pads, mounted on a
device called a brake caliper, is forced mechanically, hydraulically, pneumatically, or
electromagnetically against both sides of the disc. Friction causes the disc and attached wheel to
slow or stop. Brakes convert motion to heat, and if the brakes get too hot, they become less
effective, a phenomenon known as brake fade. The development and use of disc-type brakes
began in England in the 1890s. The first caliper-type automobile disc brake was patented by
Frederick William Lanchester in his Birmingham, UK factory in 1902 and used successfully on
Lanchester cars. Compared to drum brakes, disc brakes offer better stopping performance,
because the disc is more readily cooled. As a consequence disc brakes are less prone to brake
fade, and recover more quickly from immersion (wet brakes are less effective). Most drum brake
designs have at least one leading shoe, which gives a servo-effect. By contrast, a disc brake has
no self-servo effect and its braking force is always proportional to the pressure placed on the
brake pad by the braking system via any brake servo, braking pedal or lever. This tends to give
the driver better "feel" to avoid impending lockup. Drums are also prone to "bell mouthing", and
trap worn lining material within the assembly, both causes of various braking problems.

HISTORY

Disc-style brakes development and use began in England in the 1890s. The first caliper-
type automobile disc brake was patented by Frederick William Lanchester in his Birmingham
factory in 1902 and used successfully on Lanchester cars. However, the limited choice of metals
in this period meant that he had to use copper as the braking medium acting on thedisc. The poor
state of the roads at this time, no more than dusty, rough tracks, meant that the copper wore
quickly, making the disc brake system non-viable (as recorded in The Lanchester

1
Legacy). It took another half century for his innovation to be widely adopted.

The 1950 Crosley Hot Shot is often given credit for the first U.S. production disc brakes
but the Chrysler Crown Imperial actually had them first as standard equipment at the beginning
of the 1949 model year. The Crosley disc was a Goodyear development, a caliper type with
ventilated rotor, originally designed for aircraft applications. Only the Hot Shot featured it. Lack
of sufficient research caused enormous reliability problems, especially in regions requiring the
use of salt on winter roads, such as sticking and corrosion. Drum brake conversions for Hot Shots
were quite popular. The Chrysler four-wheel disc brake system was more complex and expensive
than Crosley's, but far more efficient and reliable. It was built by Auto Specialties Manufacturing
Company (Ausco) of St. Joseph, Michigan, under patents of inventor H.L. Lambert, and was first
tested on a 1939 Plymouth. Unlike the caliper disc, the Ausco-Lambert used twin expanding
discs that rubbed against the inner surface of a cast-iron brake drum, which doubled as the brake
housing. The discs spread apart to create friction against the inner drum surface through the
action of standard wheel cylinders. Chrysler discs were "self-energizing," in that some of the
braking energy itself contributed to the braking effort. This was accomplished by small balls set
into oval holes leading to the brake surface. When the disc made initial contact with the friction
surface, the balls would be forced up the holes forcing the discs further apart and augmenting the
braking energy. This made for lighter braking pressure than with calipers, avoided brake fade,
promoted cooler running, and provided one-third more friction surface than standard Chrysler
twelve-inch drums. But because of the expense, the brakes were only standard on the Chrysler
Crown Imperial through 1954 and the Town and Country Newport in 1950. They were optional,
however, on other Chryslers, priced around $400, at a time when an entire Crosley Hot Shot
retailed for $935. Today's owners consider the Ausco-Lambert very reliable and powerful, but
admit its grabbiness and sensitivity.

Reliable caliper-type disc brakes were developed in the UK by Dunlop and first appeared
in 1953 on the Jaguar C-Type racing car. The 1955 Citroën DS featuring powered inboard front
disc brakes was the first French application of this technology, while the 1956 Triumph TR3 was
the first English production car to feature modern disc brakes. The first production car to have
disc brakes at all 4 wheels was the Austin-Healey 100S in 1954.[3] The first British company to
market a production saloon (sedan) fitted with disc brakes to all four wheels was Jensen Motors

2
with the

3
introduction of a Deluxe version of the Jensen 541 with Dunlop disc brakes. The first German
production car with disc brakes was the 1961 Mercedes-Benz 220SE coupe featuring British-
built Girling units on the front. The next American production automobile equipped with caliper-
type disc brakes was the 1963 Studebaker Avanti (the Bendix system was optional on some of
the other Studebaker models.). Front disc brakes became standard equipment in 1965 on the
Rambler Marlin (the Bendix units were optional on all American Motors' Rambler Classic and
Ambassador models, as well as on the Ford Thunderbird,and the Lincoln Continental. A four-
wheel disc brake system was also introduced in 1965 on the Chevrolet Corvette Stingray

Compared to drum brakes, disc brakes offer better stopping performance, because the disc
is more readily cooled. As a consequence discs are less prone to the "brake fade" caused when
brake components overheat; and disc brakes recover more quickly from immersion (wet brakes
are less effective). Most drum brake designs have at least one leading shoe, which gives a servo-
effect; see leading/trailing drum brake. By contrast, a disc brake has no self-servo effect and its
braking force is always proportional to the pressure placed on the brake pad by the braking
system via any brake servo, braking pedal or lever; this tends to give the driver better "feel" to
avoid impending lockup. Drums are also prone to "bell mouthing", and trap worn lining material
within the assembly, both causes of various braking problems. Many early implementations for
automobiles located the brakes on the inboard side of the driveshaft, near the differential, but
most brakes today are located inside the road wheels. (An inboard location reduces the un sprung
weight and eliminates a source of heat transfer to the tires.)Disc brakes were most popular on
sports cars when they were first introduced, since these vehicles are more demanding about brake
performance. Discs have now become the more common form in most passenger vehicles,
although many (particularly light weight vehicles) use drum brakes on the rear wheels to keep
costs and weight down as well as to simplify the provisions for a parking brake. As the front
brakes perform most of the braking effort, this can be a reasonable compromise.The first
motorcycles to use disc brakes were racing vehicles. The first mass-produced road-going
motorcycle to sport a disc-brake was the 1969 Honda CB750. Disc brakes are now common on
motorcycles, mopeds and even mountain bikes.Historically, brake discs were manufactured
throughout the world with a strong concentration in Europe and America. Between 1989 and
2005, manufacturing of brake discs migrated predominantly to China.

4
BROKEN DISC

The brake disc is the component of a disc brake against which the brake pads are applied.
The material is typically grey iron, a form of cast iron. The design of the disc varies somewhat.
Some are simply solid, but others are hollowed out with fins or vanes joining together the disc's
two contact surfaces (usually included as part of a casting process). The weight and power of the
vehicle determines the need for ventilated discs. The "ventilated" disc design helps to dissipate
the generated heat and is commonly used on the more-heavily-loaded front discs.Many higher-
performance brakes have holes drilled through them. This is known as cross-drilling and was
originally done in the 1960s on racing cars. For heat dissipation purposes, cross drilling is
stillused on some braking components, but is not favored for racing or other hard use as the holes
are a source of stress cracks under severe conditions.Discs may also be slotted, where shallow
channels are machined into the disc to aid in removing dust and gas. Slotting is the preferred
method in most racing environments to remove gas and water and to deglaze brake pads. Some
discs are both drilled and slotted. Slotted discs are generally not used on standard vehicles
because they quickly wear down brake pads; however, this removal of material is beneficial to
race vehicles since it keeps the pads soft and avoids verification of their surfaces.As a way of
avoiding thermal stress, cracking and warping, the disc is sometimes mounted in a half loose way
to the hub with coarse splines. This allows the disc to expand in a controlled symmetrical way
and with less unwanted heat transfer to the hub.On the road, drilled or slotted discs still have a
positive effect in wet conditions because the holes or slots prevent a film of water building up
between the disc and the pads. Cross-drilled discs may eventually crack at the holes due to metal
fatigue. Cross-drilled brakes that are manufactured poorly or subjected to high stresses will crack
much sooner and more severely.This section does not cite any references or sources. Discs are of
a floating design where the disc rides on small dowels and is allowed to slightly move laterally.
This allows for better disc centering when used with a fixed caliper. It can also prevent heat
transfer to the wheel hub under hard braking. This allows the disc to expand while heating up
without increasing tension in such a way that the disc would become warped. Calipers have
evolved from simple "single-piston" units to two-, four- and even six-piston items. Since
(compared to cars) motorcycles have a higher centre of gravity wheelbase ratio, they experience
more weight transference when braking. The front brake(s) provide most of the required
deceleration, while the rear brake serves mainly to "balance"
5
the motorcycle during braking. A modern sports bike will typically have twin front discs of large
diameter, but only a very much smaller single rear disc. This is because the rear wheel can only
transfer a fraction of the stopping power due to the weight transfer to the front that occurs when
braking. The same effect lets the front wheel transfer a lot more stopping power before locking
up.

Mountain bike disc brakes may range from simple, mechanical (cable) systems, to
expensive and powerful, quad-piston hydraulic disc systems, commonly used on downhill racing
bikes. Improved technology has seen the creation of the first vented discs for use on mountain
bikes, similar to those on cars, introduced to help avoid heat fade on fast alpine descents.
Although less common, discs are also used on road bicycles for all-weather cycling with
predictable braking, although drums are sometimes preferred as harder to damage in crowded
parking, where discs are sometimes bent. Most bicycle brake discs are made of steel. Stainless
steel is preferred due to its anti-rust properties. Some lightweight discs are made of titanium or
aluminium. Discs are thin, often about 2 mm. Some use a two-piece floating disc style, others use
a floating caliper, others use pads that float in the caliper, and some use one moving pad that
makes the caliper slide on its mounts, pulling the other pad into contact with the disc. Because
the "motor" is small, an uncommon feature of bicycle brakes is that the pads retract to eliminate
residual drag when the brake is released. In contrast, most other brakes drag the pads lightly
when released so as to minimise initial operational travel. Disc brakes are increasingly used on
very large and heavy road vehicles, where previously large drum brakes were nearly universal.
One reason is that the disc's lack of self-assist makes brake force much more predictable, so peak
brake force can be raised without more risk of braking-induced steering or jackknife on
articulated vehicles. Another is disc brakes fade less when hot, and in a heavy vehicle air and
rolling drag and engine braking are small parts of total braking force, so brakes are used harder
than on lighter vehicles, and drum brake fade can occur in a single stop. For these reasons, a
heavy truck with disc brakes can stop in about 120% the distance of a passenger car, but with
drums stopping takes about 150% the distance. In Europe, stopping distance regulations
essentially require disc brakes for heavy vehicles. In the U.S., drums are allowed and are
typically preferred for their lower purchase price, despite higher total lifetime cost and more
frequent service intervals. A railroad bogie and disc brakes

6
 Still-larger discs are used for railroad cars and some airplanes. Passenger rail cars and
light rail vehicles often use disc brakes outboard of the wheels, which helps ensure a free
flow of

7
cooling air. In contrast, some airplanes have the brake mounted with very little cooling and the
brake gets quite hot in a stop, but this is acceptable as there is then time for cooling, and where
the maximum braking energy is very predictable.

For automotive use, disc brake discs are commonly manufactured out of a material called
grey iron. The SAE maintains a specification for the manufacture of grey iron for various
applications. For normal car and light-truck applications, SAE specification J431 G3000
(superseded to G10) dictates the correct range of hardness, chemical composition, tensile
strength, and other properties necessary for the intended use. Some racing cars and airplanes use
brakes with carbon fiber discs and carbon fiber pads to reduce weight. Wear rates tend to be
high, and braking may be poor or grabby until the brake is hot.

RACING

Reinforced carbon brake disc on a Ferrari F430 Challenge race car.In racing and very-
high-performance road cars, other disc materials have been employed. Reinforced carbon discs
and pads inspired by aircraft braking systems such as those used on Concorde wereintroduced in
Formula One by Brabham in conjunction with Dunlop in 1976. Carbon–carbon braking is now
used in most top-level motorsport worldwide, reducing un sprung weight, giving better frictional
performance and improved structural properties at high temperatures, compared to cast iron.
Carbon brakes have occasionally been applied to road cars, by the French Venturi sports car
manufacturer in the mid 1990s for example, but need to reach a very high operating temperature
before becoming truly effective and so are not well suited to road use. The extreme heat
generated in these systems is easily visible during night racing, especially at shorter tracks. It is
not uncommon to be able to look at the cars, either live in person or on television and see the
brake discs glowing red during application.

Ceramic composites

Mercedes Benz AMG carbon ceramic

brake Porsche Carrera S composite ceramic

brake

8
Ceramic discs are used in some high-performance cars and heavy vehicles.

9
The first development of the modern ceramic brake was made by British engineers working in
the railway industry for TGV applications in 1988. The objective was to reduce weight, the
number of brakes per axle, as well as provide stable friction from very high speeds and all
temperatures. The result was a carbon-fibre-reinforced ceramic process which is now used in
various forms for automotive, railway, and aircraft brake applications.

Due to the high heat tolerance and mechanical strength of ceramic composite discs, they
are often used on exotic vehicles where the cost is not prohibitive to the application. They are
also found in industrial applications where the ceramic disc's light weight and low-maintenance
properties justify the cost relative to alternatives. Composite brakes can withstand temperatures
that would make steel discs bendable.

Porsche's Composite Ceramic Brakes (PCCB) are siliconized carbon fiber, with very high
temperature capability, a 50% weight reduction over iron discs (therefore reducing the unsprung
weight of the vehicle), a significant reduction in dust generation, substantially increased
maintenance intervals, and enhanced durability in corrosive environments over conventional iron
discs. Found on some of their more expensive models, it is also an optional brake for all street
Porsches at added expense. It is generally recognized by the bright yellow paintwork on the
aluminum six-piston calipers that are matched with the discs. The discs are internally vented
much like cast-iron ones, and cross-drilled.

ADJUSTMENT MECHANISM

In automotive applications, the piston seal has a square cross section, also known as a
square-cut seal. As the piston moves in and out, the seal drags and stretches on the piston,
causing the seal to twist. The seal distorts approximately 1/10 of a millimeter. The piston is
allowed to move out freely, but the slight amount of drag caused by the seal stops the piston from
fully retracting to its previous position when the brakes are released, and so takes up the slack
caused by the wear of the brake pads, eliminating the need for return springs.

As the seal returns to its original shape when the brakes are released, it also helps to hold
the brake pads slightly away from the rotors. As the seal wears out or loses elasticity with age,
the action the seal provides will diminish, and the brake pads will drag more on the rotors in
the
10
neutral position. This is why calipers must be pushed in with a brake caliper retraction tool when
installing new brake pads.

In some rear disc calipers, the parking brake activates a mechanism inside the caliper that performs
some of the same function.

DISC DAMAGE MODES

Discs are usually damaged in one of four ways: scarring, cracking, warping or excessive
rusting. Service shops will sometimes respond to any disc problem by changing out the discs
entirely, This is done mainly where the cost of a new disc may actually be lower than the cost of
labour to resurface the old disc. Mechanically this is unnecessary unless the discs have reached
manufacturer's minimum recommended thickness, which would make it unsafe to use them, or
vane rusting is severe (ventilated discs only). Most leading vehicle manufacturers recommend
brake disc skimming (US: turning) as a solution for lateral run-out, vibration issues and brake
noises. The machining process is performed in a brake lathe, which removes a very thin layer off
the disc surface to clean off minor damage and restore uniform thickness. Machining the disc as
necessary will maximise the mileage out of the current discs on the vehicle.

SCARRING

Scarring (US: Scoring) can occur if brake pads are not changed promptly when they reach
the end of their service life and are considered worn out. Once enough of the friction material has
worn away, the pad's steel backing plate (for glued pads) or the pad retainer rivets (for riveted
pads) will bear directly upon the disc's wear surface, reducing braking power and making
scratches on the disc. Generally a moderately scarred / scored disc, which operated satisfactorily
with existing brake pads, will be equally usable with new pads. If the scarring is deeper but not
excessive, it can be repaired by machining off a layer of the disc's surface. This can only be done
a limited number of times as the disc has a minimum rated safe thickness. The minimum
thickness value is typically cast into the disc during manufacturing on the hub or the edge of the
disc. In Pennsylvania, which has one of the most rigorous auto safety inspection programs in
North America, an automotive disc cannot pass safety inspection if any scoring is deeper than

11
.015 inches

12
(0.38 mm), and must be replaced if machining will reduce the disc below its minimum safe
thickness.To prevent scarring, it is prudent to periodically inspect the brake pads for wear. A tire
rotation is a logical time for inspection, since rotation must be performed regularly based on
vehicle operation time and all wheels must be removed, allowing ready visual access to the brake
pads. Some types of alloy wheels and brake arrangements will provide enough open space to
view the pads without removing the wheel. When practical, pads that are near the wear-out point
should be replaced immediately, as complete wear out leads to scarring damage and unsafe
braking. Many disc brake pads will include some sort of soft steel spring or drag tab as part of
the pad assembly, which is designed to start dragging on the disc when the pad is nearly worn
out. The result is a moderately loud metallic squealing noise, alerting the vehicle user that service
is required, and this will not normally scar the disc if the brakes are serviced promptly. A set of
pads can be considered for replacement if the thickness of the pad material is the same or less
than the thickness of the backing steel. In Pennsylvania, the standard is 1/32"

Cracking
Cracking is limited mostly to drilled discs, which may develop small cracks around edges
of holes drilled near the edge of the disc due to the disc's uneven rate of expansion in severe duty
environments. Manufacturers that use drilled discs as OEM typically do so for two reasons:
appearance, if they determine that the average owner of the vehicle model will prefer the look
while not overly stressing the hardware; or as a function of reducing the unsprung weight of the
brake assembly, with the engineering assumption that enough brake disc mass remains to absorb
racing temperatures and stresses. A brake disc is a heat sink, but the loss of heat sink mass may
be balanced by increased surface area to radiate away heat. Small hairline cracks may appear in
any cross drilled metal disc as a normal wear mechanism, but in the severe case the disc will fail
catastrophically. No repair is possible for the cracks, and if cracking becomes severe, the disc
must be replaced. These cracks occur due to the phenomenon of low cycle fatigue as a result of
repeated hard braking.

Rusting

The discs are commonly made from cast iron and a certain amount of surface rust is
normal. The disc contact area for the brake pads will be kept clean by regular use, but a vehicle
that
13
is stored for an extended period can develop significant rust in the contact area that may reduce
braking power for a time until the rusted layer is worn off again. Over time, vented brake discs
may develop severe rust corrosion inside the ventilation slots.

CALIPERS

GM disc brake caliper (twin-piston, floating) removed from brake pad for changing pads

The brake caliper is the assembly which houses the brake pads and pistons. The pistons
are usually made of plastic, aluminium or chrome-plated steel. Callipers are of two types,
floating or fixed. A fixed caliper does not move relative to the disc and is thus less tolerant of
disc imperfections. It uses one or more single or pairs of opposing pistons to clamp from each
side of the disc, and is more complex and expensive than a floating caliper.

A floating caliper (also called a "sliding caliper") moves with respect to the disc, along a
line parallel to the axis of rotation of the disc; a piston on one side of the disc pushes the inner
brake pad until it makes contact with the braking surface, then pulls the caliper body with the
outer brake pad so pressure is applied to both sides of the disc. Floating caliper (single piston)
designs are subject to sticking failure, caused by dirt or corrosion entering at least one mounting
mechanism and stopping its normal movement. This can lead to the caliper's pads rubbing on the
disc when the brake is not engaged or engaging it at an angle. Sticking can result from infrequent
vehicle use, failure of a seal or rubber protection boot allowing debris entry, dry-out of the grease
in the mounting mechanism and subsequent moisture incursion leading to corrosion, or some
combination of these factors. Consequences may include reduced fuel efficiency, extreme
heating of the disc or excessive wear on the affected pad. A sticking front caliper may also cause
steering vibration.

BRAKE PADS

Brake pads are designed for high friction with brake pad material embedded in the disc in
the process of bedding while wearing evenly. Friction can be divided into two parts. They are:
adhesive and abrasive.Depending on the properties of the material of both the pad and the disc
and the configuration and the usage, pad and disc wear rates will vary considerably.

14
 The brake pads must usually be replaced regularly (depending on pad material), and some
are equipped with a mechanism that alerts drivers that replacement is needed, such as a thin piece
of soft metal that rubs against the disc when the pads are too thin causing the brakes to squeal, a
soft metal tab embedded in the pad material that closes an electric circuit and lights a warning
light when the brake pad gets thin, or an electronic sensor. B Generally road-going vehicles have
two brake pads per caliper, while up to six are installed on each racing caliper, with varying
frictional properties in a staggered pattern for optimum performance.Early brake pads (and
linings) contained asbestos, producing dust which should not be inhaled. Although newer pads
can be made of ceramics, Kevlar, and other plastics, inhalation of brake dust should still be
avoided regardless of material.

BRAKE SQUEAL

Sometimes a loud noise or high pitched squeal occurs when the brakes are applied. Most
brake squeal is produced by vibration (resonance instability) of the brake components, especially
the pads and discs (known as force-coupled excitation). This type of squeal should not negatively
affect brake stopping performance. Simple techniques like adding chamfers to linings, greasing
or gluing the contact between caliper and the pads (finger to back plate, piston to back plate),
bonding insulators (damping material) to pad back plate, inclusion of a brake shim between the
brake pad and back plate, etc. may help to reduce squeal. Cold weather combined with high
early-morning humidity (dew) often worsens brake squeal, although the squeal stops when the
lining reaches regular operating temperatures. Dust on the brakes may also cause squeal; there
are many commercial brake cleaning products that can be used to remove dust and contaminants.
Finally, some lining wear indicators, located either as a semi-metallic layer within the brake pad
material or with an external squealer "sensor", are also designed to squeal when the lining is due
for replacement. The typical external sensor is fundamentally different because it occurs when
the brakes are off, and goes away when the brakes are on.Overall brake squeal can be annoying to
the vehicle passengers, passers-by, pedestrians, etc. especially as vehicle designs become quieter.
Noise, vibration, and harshness (NVH) are among the most important priorities for today's
vehicle manufacturers.Apart from noise generated from squeal, brakes may also develop a
phenomenon called brake judder or shudder.

15
 AIM OF THE PROJECT
The main aim of the thesis is to design analysis disc brake rotor by using creo and Ansys
workbench to know static and thermal and dynamic behaviour of the object, in this process 2
materials were chosen to analyse the object, and calculating results like deformation, stress, heat
transfer rate and natural frequency values. Finally concluding thesis with optimum material with
suitable graphs and tables

BRAKE JUDDER

Brake judder is usually perceived by the driver as minor to severe vibrations transferred
through the chassis during braking. The judder phenomenon can be classified into two distinct
subgroups: hot (or thermal), or cold judder. Hot judder is usually produced as a result of longer,
more moderate braking from high speed where the vehicle does not come to a complete stop. It
commonly occurs when a motorist decelerates from speeds of around 120 km/h (74.6 mph) to
about 60 km/h (37.3 mph), which results in severe vibrations being transmitted to the driver.
These vibrations are the result of uneven thermal distributions, or hot spots. Hot spots are
classified as concentrated thermal regions that alternate between both sides of a disc that distort it
in such a way that produces a sinusoidal waviness around its edges. Once the brake pads (friction
material/brake lining) comes in contact with the sinusoidal surface during braking, severe
vibrations are induced, and can produce hazardous conditions for the person driving the
vehicle.Cold judder, on the other hand, is the result of uneven disc wear patterns or disc thickness
variation (DTV). These variations in the disc surface are usually the result of extensive vehicle
road usage. DTV is usually attributed to the following causes: waviness and roughness of disc
surface, misalignment of axis (runout), elastic deflection, wear and friction material transfers.

Brake dust

When braking force is applied, the act of abrasive friction between the brake pad and the
rotor wears both the rotor and pad away. The brake dust that is seen deposited on wheels,
calipers and other braking system components consists mostly of rotor material. Brake dust can
damage the finish of most wheels if not washed off.[citation needed] Generally a brake pad that
aggressively abrades more rotor material away, such as metallic pads, will create more brake
16
dust.

17
 CHAPTER 2

LITERATURE REVIEW
A lot of research has been done in the area of modelling of components in closed
mathematical/physical models. Commercial Computer Aided Engineering (CAE) software has
been available since 1978. Over the years, the scope of such software has expanded beyond
filling analysis to include analysis

Mirza Grebovic, (2007) examined the report is to present the reader with some common
vented brake rotor designs, specifically rotors of the blank, cross drilled, and slotted rotor face
designs and how each of these effects performance parameters and service life of the component.
Furthermore, different cooling or venting vanes and their effects will be discussed as well. Data
from various literature sources will be compiled to explain to the reader why these different
brake rotor designs exist and a comparison betweeneach will be attempted. Finally, conclusions
and recommendations on what to look out for and how to decide on a brake rotor design for a
specific automotive application will be made. Applications such as daily driving, spirited driving
with some track exposure, and racing will all be considered.

 Limpert, Rudolf, examined the study of fade in conventional disc brakes results from
two basic causes. (1) The brake pads overheat, reducing their coefficient of friction which
decreases braking ability, and (2) Excessive heat in the brake pads is transferred via the hydraulic
pistons to the brake fluid, which boils and produces bubbles in the brake lines. The full circle
disc Brake resists these fade inducing causes by: (1) Distributing in-pad heat over a greater area
and conducting heat both away from and through the brake pads into the brake body structure to
enable more efficient heat dissipation, and (2) isolating the hydraulic cylinder from the brake
pads so that direct heat is not transferred to the brake fluid.

. A.Belhocine, M. Bouchetara [3], The main purpose of this study is to analyse the
thermo mechanical behaviour of the dry contact between the brake disc and pads during the
braking phase. The simulation strategy is based on computer code ANSYS11. The modelling of
transient temperature in the disc is actually used to identify the factor of geometric design of the
disc to install the ventilation system in vehicles. The thermo-structural analysis is then used with
coupling
18
to determine the deformation established and the Von Mises stresses in the disc, the contact
pressure distribution in pads. The results are satisfactory when compared to those found in
previous studies.

Manjunath T. V, Dr Suresh P. M [4], The disc brake is a device for slowing or stopping
the rotation of a wheel. Repetitive braking of the vehicle leads to heat generation during each
braking event. Transient Thermal and Structural Analysis of the Rotor Disc of Disk Brake is
aimed at evaluating the performance of disc brake rotor of a car under severe braking conditions
and there by assist in disc rotor design and analysis.Disc brake model and analysis is done using
ANSYS workbench 14.5. The main purpose of this study is to analysis the thermo mechanical
behaviour of the dry contact of the brake disc during the braking phase. The coupled thermal-
structural analysis is used to determine the deformation and the Von Mises stress established in
the disc for the both solid and ventilated disc with two different materials to enhance
performance of the rotor disc. A comparison between analytical and results obtained from FEM
is done and all the values obtained from the analysis are less than their allowable values. Hence
best suitable design, material and rotor disc is suggested based on the performance, strength and
rigidity criteria.

K.Sowjanya, S.Suresh[5], This paper deals with the analysis of Disc Brake. A Brake is a
device by means of which artificial frictional resistance is applied to moving machine member,
in order to stop the motion of a machine.Disc brake is usually made of Cast iron, so it is being
selected for investigating the effect of strength variations on the predicted stress distributions.
Aluminium Metal Matrix Composite materials are selected and analysed. The results are
compared with existing disc rotor. The model of Disc brake is developed by using Solid
modelling software Pro/E (Creo-Parametric 1.0).Further Static Analysis is done by using
ANSYS Workbench. Structural Analysis is done to determine the Deflection, Normal Stress,
Vonmises stress

VirajParab,KunalNaik, Prof A. D. Dhale [6], Disc (Rotor) brakes are exposed to large
thermal stresses during routine braking and extraordinary thermal stresses during hard braking.
The aim of the project is to design, model a disc. Modelling is done using catia. Structural and
Thermal analysis is to be done on the disc brakes using three materials Stainless Steel and Cast

19
iron & carbon carbon composite. Structural analysis is done on the disc brake to validate the
strength of the disc brake and thermal analysis is done to analyze the thermal properties.

Comparison can be done for deformation; stresses, temperature etc. form the three
materials to check which material is best. Catia is a 3D modelling software widely used in the
design process. ANSYS is general-purpose finite element analysis (FEA) software package.
Finite Element Analysis is a numerical method of deconstructing a complex system into very
small pieces (of user-designated size) called elements.

Guru Murthy Nathi, T N Charyulu, K.Gowtham, P Satish Reddy [7]. The motive of
undertaking this project of “Coupled Structural / Thermal Analysis of Disc Brake” is to study
and evaluate the performance under severe braking conditions and there by assist in disc rotor
design and analysis. This study is of disc brake used for cars. ANSYS package is a dedicated
finite element package used for determining the temperature distribution, variation of stresses
and deformation across the disc brake profile. In this present work, an attempt has been made to
investigate the effect of stiffness, strength and variations in disc brake rotor design on the
predicted stress and temperature distributions. By identifying the true design features, the
extended service life and long term stability is assured. A transient thermal analysis has been
carried out to investigate the temperature variation across the disc using axisymmetric elements.
Further structural analysis is also carried out by coupling thermal analysis.

Swapnil R. Abhang, D. P. Bhaskar [8], Each single system has been studied and
developed in order to meet safety requirement. Instead of having air bag, good suspension
systems, good handling and safe cornering, there is one most critical system in the vehicle which
is brake systems.Without brake system in the vehicle will put a passenger in unsafe position.
Therefore, it is must for all vehicles to have proper brake system. In this paper carbon ceramic
matrix disc brake material use for calculating normal force, shear force and piston force. And
also calculating the brake distance of disc brake. The standard disc brake two wheelers model
using in Ansys and done the Thermal analysis and Modal analysis also calculate the deflection
and Heat flux, Temperature of disc brake model. This is important to understand action force and
friction force on the disc brake new material, how disc brake works more efficiently, which can
help to reduce the accident that may happen in each day

20
 CHAPTER 3

METHODOLOGY

INTRODUCTION CREO

3.1. CAD

Computer aided design (cad) is defined as any activity that

involves the effective use of the computer to create, modify, analyze, or document an
engineering design. CAD is most commonly associated with the use of an interactive computer
graphics system, referred to as cad system. The term CAD/CAM system is also used if it
supports manufacturing as well as design applications

Introduction to CREO

CREO is a suite of programs that are used in the design, analysis, and manufacturing of a
virtually unlimited range of product CREO is a parametric, feature-based solid modeling
system, “Feature based” means that you can create part and assembly by defining feature like
pad, rib, slots, holes, rounds, and so on, instead of specifying low-level geometry like lines, arcs,
and circle& features are specifying by setting values and attributes of element such as reference
planes or surfaces direction of creation, pattern parameters, shape, dimensions and others.

“Parametric” means that the physical shape of the part or assembly

is driven by the values assigned to the attributes (primarily dimensions) of its features.
Parametric may define or modify a feature’s dimensions or other attributes at any time.

For example, if your design intent is such that a hole is centered on a

block, you can relate the dimensional location of the hole to the block dimensions using a
numerical formula; if the block dimensions change, the centered hole position will be
recomputed automatically. “Solid Modeling” means that the computer model to create it able
to contain all the information that a real solid object would have. The most useful thing about the
solid modeling is that it is impossible to create a computer model that is ambiguous or physically
non- realizable.

21
 There are six core CREO concepts. Those are:

 Solid Modeling
 Feature Based
 Parametric
 Parent / Child Relationships
 Associative
 Model Centric
Capabilities and Benefits:

1. Complete 3D modeling capabilities enable you to exceed quality arid time to arid time
to market goals.
2. Maximum production efficiency through automated generation of associative C tooling
design, assembly instructions, and machine code.
3. Ability to simulate and analysis virtual prototype to improve production performance and
optimized product design.
4. Ability to share digital product data seamlessly among all appropriate team members
5. Compatibility with myriad CAD tools-including associative data exchange and industry
standard data formats.
Features of CREO

CREO is a one-stop for any manufacturing industry. It offers effective feature,

incorporated for a wide variety of purpose. Some of the important features are as follows:

 Simple and powerful tool

 Parametric design
 Feature-based approach
 Parent child relationship
 Associative and model centric
Simple and Powerful Tool

CREO tools are used friendly. Although the execution of any operation using the tool can
create a highly complex model

22
Parametric Design

CREO designs are parametric. The term “parametric” means that the 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

Feature-Based Approach

Features are the basic building blocks required to create an object. CREO wildfire models
are based on the series of feature. 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.

The idea behind feature based modeling is that the designer construct on object, composed
of individual feature that describe the manner in which the geometry supports the object, if its
dimensions change. The first feature is called the base feature.

Parent Child Relationship

The parent child relationship is a powerful way to capture your design intent in a model. This
relationship naturally occurs among features, during the modeling process. When you create a
new feature, the existing feature that are referenced, become parent to the feature.

Associative and Model Centric

CREO drawings are model centric. This means that CREO 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.

CREO Basic Design Modes

When a design from conception to completion in CREO, the design information goes through
three basic design steps.

1. Creating the component parts of the design

2. Joining the parts in an assembly that records the relative position of the parts.
23
 3. Creating mechanical drawing based on the information in the parts and the assembly.
3.6 Assembly in CREO:
Bottom-Up Design (Modeling):
The components (parts) are created first and then added to the assembly file. This technique is
particularly useful when parts already exist from previous designs and are being re-used.
Top-Down Design (Modeling):
The assembly file is created first and then the components are created in
the assembly file. The parts are build relative to other components. Useful in new designs
In practice, the combination of Top-Down and Bottom-Up approaches is used. As you often use
existing parts and create new parts in order to meet your design needs.
Degrees of Freedom:
An object in space has six degrees of freedom.
• Translation – movement along X, Y, and Z axis (three degrees of freedom)
• Rotation – rotate about X, Y, and Z axis (three degrees of
freedom) Assembly Constraints:
In order to completely define the position of one part relative to another, we must constrain all of
the degrees of freedom COINCIDENT, OFFSET
OFFSET
Two surfaces are made parallel with a specified offset distance.
COINCIDENT

Two selected surfaces become co-planar and face in the same direction. Can also be applied to
revolved surfaces. This constrains 3 degrees of freedom (two rotations and one translation).
When Align is used on revolved surfaces, they become coaxial (axes through the centers align).

CREO Modules:-

 Sketcher (2D)

 Part (3D)

 Assembly

 Drawing and Drafting

24
  Sheet Metal

PRO-E/CREO-2 STEPS

Select creoopen

Selectnewenter part name as disc rotor

25
And next you will get one window

Select Extrudeplacementselect one plane

26
After that you will get sketcher window

Select circle enter dimensions

Thenokenter extrude length

27
To repeat holes do the same process

28
Then select revolvedraw the sketch

Then okrevolve angle

29
To crate holesdraw circlesok

Select extrudeselect patternselect axisenter valuesok

30
31
32
Disc brake final model

33
 CHAPTER 4

ANALYSIS

ANSYS is an Engineering Simulation Software (computer aided Engineering). Its tools

cover Thermal, Static, Dynamic, and Fatigue finite element analysis along with other tools all
designed to help with the development of the product. The company was founded in 1970 by Dr.
John A. Swanson as Swanson Analysis Systems, Inc. SASI. Its primary purpose was to develop and
market finite element analysis software for structural physics that could simulate static
(stationary), dynamic (moving) and heat transfer (thermal) problems. SASI developed its
business in parallel with the growth in computer technology and engineering needs. The
company grew by 10 percent to 20 percent each year, and in 1994 it was sold. The new owners
took SASI’s leading software, called ANSYS®, as their flagship product and designated
ANSYS, Inc. as the new company name.

BENEFITS OF ANSYS

 The ANSYS advantage and benefits of using a modular simulation system in the
design process are well documented. According to studies performed by the Aberdeen
Group, best-in-class companies perform more simulations earlier. As a leader in virtual
prototyping, ANSYS is unmatched in terms of functionality and power necessary to
optimize components and systems.
 The ANSYS advantage is well-documented.

 ANSYS is a virtual prototyping and modular simulation system that is easy to

use and extends to meet customer needs, making it a low-riskinvestment that can
expand as value is demonstrated within a company. It is scalable to all levels of the
organization, degrees of analysis complexity, and stages of product development.
Finite Element Method

General Description of the Finite Element Method:

34
In the finite element method, the actual continuum or body of matter like solid, liquid or gas is
represented as assemblage of sub divisions called finite elements. These elements are considered to be
interconnected at specified joints, which are called nodes or nodal points. The nodes usually lie on the
element boundaries where adjacent elements are considered to be connected. Since the actual variation of
the field variable (like displacement, stress, temperature, pressure and velocity) inside the continuum is
not known, we assume that the variation of field variable inside a finite element can be approximated by a
simple function. These approximating functions (also called interpolation models) are defined in terms of
the values at the nodes.

Structural Analysis:

Structural analysis is probably the most common application of the finite element
method. The term structural (or structure) implies not only civil engineering structures such as
ship hulls, aircraft bodies, and machine housings, as well as mechanical components such as
pistons, machine parts, and tools.

Types of Structural Analysis:

Different types of structural analysis are:

 Static analysis
 Modal analysis
 Harmonic analysis
 Transient dynamic analysis
 Spectrum analysis
 Bucking analysis
 Explicit dynamic analysis
Static 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 the static equivalent
wind arid seismic loads commonly defined in many building codes).

35
 Static analysis is used to determine the displacements, stresses, strains, and forces in
structural components caused by loads that do not induce significant inertia and damping effects.
Steady loading and response are assumed to vary slowly with respect to time.

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 stain)
 Fluencies (for nuclear swelling)
A static analysis can be either linear or non-linear. All types of non-linearities are allowed-
large deformations, plasticity, creep, stress, stiffening, contact (gap) elements, hyper elastic
elements, and so on.

Over-view of steps in a static analysis:

The procedure for a modal analysis consists of three main steps:

1. Build the model.

2. Apply loads and obtain the solution.
3. Review the results
BASIC STEPS IN ANSYS (Finite Element Software):

36
 Pre-Processing (Defining the Problem): The major steps in pre-processing are given below

 Define key points/lines/ areas/volumes.

 Define element type and material/geometric properties
 Mesh lines/ areas/volumes as required.
The amount of detail required will depend on the dimensionality of the analysis (i.e., 1D,
2D, axi-symmetric, 3D).

Solution (Assigning Loads, Constraints, And Solving): Here the loads (point or pressure),
constraints (translational and rotational) are specified and finally solve the resulting set of
equations.

Post Processing: In this stage, further processing and viewing of the results can be done such as:

 Lists of nodal displacements

 Element forces and moments
 Deflection plots
 Stress contour diagrams

Advanced Post-Processing:

37
ANSYS provides a comprehensive set of post-processing tools to display results on the models
as contours or vector plots, provide summaries of the results (like min/max values and locations).
Powerful and intuitive slicing techniques allow to get more detailed results over given parts of
your geometries. All the results can also be exported as text data or to a spreadsheet for further
calculations. Animations are provided for static cases as well as for nonlinear or transient
histories. Any result or boundary condition can be used to create customized charts.

Exploring design:

A single simulation just provides a validation of a design. ANSYS brings you to the next
level with design explorer a tool designed for fast and efficient design analysis. You will not
need more than a few mouse clicks to get a depper understanding of your design, whether you
want to examine multiple scenarios or create full response surfaces of your model and get
sensitivities to design parameters, optimize your model or perform a Six Sigma analysis.

Communicating results:

ANSYS lets you explore your design in multiple ways. All the results you get must then
be efficiently documented: ANSYS will provide you instantaneous report generation to gather all
technical data and pictures of the model in a convenient format (html, MS Word, MS
PowerPoint…).Capturing the knowledge:

38
ANSYS

For all engineers and students coming to finite element analysis or to ANSYS software

for the first time, this powerful hands-on guide develops a detailed and confident understanding

of using ANSYS's powerful engineering analysis tools. The best way to learn complex systems is

by means of hands-on experience. With an innovative and clear tutorial based approach, this

powerful book provides readers with a comprehensive introduction to all of the fundamental

areas of engineering analysis they are likely to require either as part of their studies or in getting

up to speed fast with the use of ANSYS software in working life. Opening with an introduction

to the principles of the finite element method, the book then presents an overview of ANSYS

technologies before moving on to cover key applications areas in detail. Key topics covered:

39
Introduction to the finite element method Getting started with ANSYS software stress analysis

dynamics of machines fluid dynamics problems thermo mechanics contact and surface

mechanics exercises, tutorials, worked examples With its detailed step-by-step explanations,

extensive worked examples and sample problems, this book will develop the reader's

understanding of FEA and their ability to use ANSYS's software tools to solve their own

particular analysis problems, not just the ones set in the book.

At ANSYS, we bring clarity and insight to customers' most complex design challenges

through fast, accurate and reliable simulation. Our technology enables organizations to predict

with confidence that their products will thrive in the real world. They trust our software to help

ensure product integrity and drive business success through innovation.

Every product is a promise to live up to and surpass expectations. By simulating early and

often with ANSYS software, our customers become faster, more cost-effective and more

innovative, realizing their own product promises.

40
Ansys process
IMPORTING THE COMPONEENT FROM CAD (CREO-2) TOOL TO CAE TOOL (ANSYS):

STRUCTURAL ANALYSIS:-
1. Click on Ansys

workbench Static structural

3. Engineering dataright click enter values

41
FOR

Al-alloy

Ex:- 72*10^9 Pa

Poison ratio: 0.33

Density: 2800 Kg/m^3

Yield strength: 280Mpa

Grey cast iron

Ex: 125*10^9 Pa

Poison ratio: 0.25

Density: 7100 kg/m^3

Yield strength: 240 Mpa

4. Geometry right click import geometry import iges format model

Model imported from pro-e tool in IGES format.

42
 Imported Model View In Ansys.

Meshing

After completion of material selection here we have to create meshing for each object meshing
means it is converting single part into no of parts. And this mesh will transfer applied loads for
overall object. After completion meshing only we can solve our object. Without mesh we cannot
solve our problem. And here we are using tetra meshing and the model shown in below.

Meshing: - Volume Mesh - Tetmesh.

43
 Tet Volume Mesh.

Boundary condition

Select geometry assign material properties

Click on static structural  supports frictionless supports

Loadsforce 25000N apply

 Loads  moment 2e6 N-mm

. Solutiondeformationsolve

Repeat same process for von-misses stress, factor of safety then solve

44
 CHAPTER 5

RESULTS AND DISCUSSIONS

Deformation

Fig 5.1

Stress

45
Safety factor

Al-alloy
Deformation

46
Stress

Safety factor

47
Tables
Grey cast iron Al-alloy
Deformation (mm) 0.088468 0.14583
Stress (Mpa) 56.463 55.041
Safety factor 4.2506 5.0871

Graphs

Deformation (mm)
0.16

0.14

0.12

0.1

0.08

0.06

0.04

0.02

0
Grey cast iron Al-alloy

48
 Stress (Mpa)
57

56.5

56

55.5

55

54.5

54
Grey cast iron Al-alloy

Safety factor
5.2

4.8

4.6

4.4

4.2

3.8
Grey cast iron Al-alloy

49
 ANSYS PROCESS

IMPORTING THE COMPONEENT FROM CAD (CREO) TOOL TO CAE TOOL (ANSYS):

THERMAL ANALYSIS:-
1. Click on Ansys workbench

Thermal analysis

MATERIAL PROPERIES
Al-alloy

Young’s modulus - 72*10^9 Pa

Poison ratio: 0.33

Density: 2800 Kg/m^3

Yield strength: 280 Mpa

Thermal conductivity: 155 w/m/k

50
Grey cast iron

Young’s modulus: 125*10^9 Pa

Poison ratio: 0.25

Density: 7100 kg/m^3

Yield strength: 240

Mpa

Thermal conductivity: 54 w/m/k

4. Geometry right click import geometry import iges format model Model

imported from pro-e tool in IGES format.

Imported model

Select geometry assign material properties

Click on steady state thermal  temperature fixed supportsselect areas22^c

 Convectionselect areas film coefficient1e5 w/mm^2*c

Bulk temperature127*c apply

51
RESULTS

Existing material: Grey Cast Iron

Total temperature

Total heat flux

52
Heat flux in x-direction

Heat flux in y-direction

53
Heat flux in z-direction

Existing material: al-alloy

Total temperature

54
Total heat flux

Heat flux in x-direction

55
Heat flux in y-direction

Heat flux in z-direction

56
Heat fluxTables
Grey cast iron Al-alloy
Total temperature (*C) 24.126 22.751

Heat flux (w/mm^2) 0.0022231 0.0022527

Heat flux in x-direction 0.0020091 0.0020359

(w/mm^2)
Heat flux in y-direction 0.0014711 0.0014907
(w/mm^2)
Heat flux in z-direction 0.00201 0.0020368
(w/mm^2)

Graphs

Total temperature (*C)

24.5

24

23.5

23

22.5

22
Grey cast iron Al-alloy

57
 Heat flux (w/mm^2)
0.002255
0.00225
0.002245
0.00224
0.002235
0.00223
0.002225
0.00222
0.002215
0.00221
0.002205
Grey cast iron Al-alloy

Heat flux in x-direction (w/mm^2)

0.00204
0.002035
0.00203
0.002025
0.00202
0.002015
0.00201
0.002005
0.002
0.001995
Grey cast iron Al-alloy

58
 Heat flux in y-direction (w/mm^2)
0.001495

0.00149

0.001485

0.00148

0.001475

0.00147

0.001465

0.00146
Grey cast iron Al-alloy

Heat flux in z-direction (w/mm^2)

0.00204
0.002035
0.00203
0.002025
0.00202
0.002015
0.00201
0.002005
0.002
0.001995
Grey cast iron Al-alloy

59
5.1 Natural frequency

A sound wave is created as a result of a vibrating object. The vibrating object is the
source of the disturbance that moves through the medium. The vibrating object that creates the
disturbance could be the vocal cords of a person, the vibrating string and soundboard of a guitar
or violin, the vibrating tines of a tuning fork, or the vibrating diaphragm of a radio speaker. Any
object that vibrates will create a sound. The sound could be musical or it could be noisy; but
regardless of its quality, the sound wave is created by a vibrating object.

Nearly all objects, when hit or struck or plucked or strummed or somehow disturbed, will
vibrate. If you drop a meter stick or pencil on the floor, it will begin to vibrate. If you pluck a
guitar string, it will begin to vibrate. If you blow over the top of a pop bottle, the air inside will
vibrate. When each of these objects vibrates, they tend to vibrate at a particular frequency or a set
of frequencies. The frequency or frequencies at which an object tends to vibrate with when hit,
struck, plucked, strummed or somehow disturbed is known as the natural frequency of the
object. If the amplitudes of the vibrations are large enough and if natural frequency is within
the human frequency range, then the vibrating object will produce sound waves that are audible.
All objects have a natural frequency or set of frequencies at which they vibrate. The quality
or timbre of the sound produced by a vibrating object is dependent upon the natural frequencies
of the sound waves produced by the objects. Some objects tend to vibrate at a single frequency
and they are often said to produce a pure tone. A flute tends to vibrate at a single frequency,
producing a very pure tone. Other objects vibrate and produce more complex waves with a set of
frequencies that have a whole number mathematical relationship between them; these are said to
produce a rich sound. A tuba tends to vibrate at a set of frequencies that are mathematically
related by whole number ratios; it produces a rich tone. Still other objects will vibrate at a set of
multiple frequencies that have no simple mathematical relationship between them. These objects
are not musical at all and the sounds that they create could be described as noise. When a meter
stick or pencil is dropped on the floor, it vibrates with a number of frequencies, producing a
complex sound wave that is clunky and noisy.

60
 The natural frequency is the frequency at which a system oscillates when it is disturbed.
If you pluck a guitar string in the middle it vibrates back and forth. If you pluck the same string
10 times in a row and measure the frequency of vibration you find that it is always the same.
When plucked, the string vibrates at its natural frequency. The pendulum also had a natural
frequency. The natural frequency is important for many reasons:

1 All things in the universe have a natural frequency, and many things have more than one

. 2 If you know an object’s natural frequency, you know how it will vibrate.

3 If you know how an object vibrates, you know what kinds of waves it will create.

4 If you want to make specific kinds of waves, you need to create objects with natural
frequencies that match the waves you want.

All bodies have natural frequencies because all bodies have mass and stiffness’s. And mechanical
vibration is essentially a play between inertial and elastic force

61
 Modal analysis
Meshing

Boundary conditions

62
Grey cast iron

Mode1

Mode2

63
Mode3

Mode4

64
Mode5

Mode6

65
Al-alloy

Mode1

Mode2

66
Mode3

Mode4

67
Mode5

Mode6

68
 CHAPTER6

RESULTS

Deformation -Stress-Safety factor Table

Grey cast iron Al-alloy
Deformation (mm) 0.088468 0.14583
Stress (Mpa) 56.463 55.041
Safety factor 4.2506 5.0871

Frequency Tables
Grey cast iron Al-alloy

Mode1 (Hz) 1494.5 1968

Mode2 (Hz) 1494.8 1968.6

Mode3 (Hz) 1497.3 1981.7
Mode4 (Hz) 1642.5 2132.8
Mode5 (Hz) 1642.6 2133

Mode6 (Hz) 2182.5 2805.3

69
Heat fluxTables
Grey cast iron Al-alloy
Total temperature (*C) 24.126 22.751

Heat flux (w/mm^2) 0.0022231 0.0022527

Heat flux in x-direction 0.0020091 0.0020359

(w/mm^2)
Heat flux in y-direction 0.0014711 0.0014907
(w/mm^2)
Heat flux in z-direction 0.00201 0.0020368
(w/mm^2)

70
 CONCLUSION

In our project we have designed a break disc used in two wheeler and modeled in 3D
modeling software CREO-8.and the we analyze the break disc with different materials like
Aluminum And grey cast iron with help of fem In this Project we describes the stress distribution
of the disc break by using FEA. The finite element analysis is performed by using computer
aided design (CAD) software.

In this project we applied boundary condition as a 25000N weight and checked with existing
material (grey cast iron) and also replace break disc material grey cast iron to al-alloy by this
change we are getting less stress results for al-alloy and high safety factor also. By using al-alloy
we can reduce our disc break weight nearly 35% of original model and this model also having
less stress (55 MPa) and good safety factor 5.08. and the thermal heat flux also less (0.0022527
w/mm^2) compare to grey cast iron, and also this material minimizes the total temperature of the
object and this can increase the durability of the object

To get more accurate results here natural frequency results also calculated for each
degrees of freedom it means total 6 natural frequency results calculated, from those values al-
alloy has high frequency range compare to grey cast iron, it means al-alloy can withstand more
vibration than grey cast iron, and resonance factor will reduce compare to grey cast iron,

Finally thesis can be conclude with al-alloy material, this material perform better results
in all 3 cases and it can increase the overall performance of the object

71
 REFERENCES
1 Mirza Grebovic, “Investigation of the Effects on Braking Performance of Different Brake Rotor
Designs”.2013

2 Limpert, Rudolf “Brake Design and Safety”, Society of Automotive Engineers. Inc, PA, USA,
2012

3 Warren Chan, “Analysis of Heat Dissipation in Mechanical Braking Systems”. 2012

4 David A. Johnson, Bryan A. Sperandei, et.al.,“Analysis of the Flow Through a Vented

Automotive Brake Rotor,2011

5 David Antanaitisand Anthony Rifici, “The Effect of Rotor Crossdrilling on Brake Performance”.

SAE 2006-01-0691

6 Brake Design and Safety, 2nd Ed., Rudolf Limpert, 2010..

7 Brake Design and Safety, 2nd Ed., Rudolf Limpert, 2010.

8 James D. Halderman, Automotive Braking S ystem, 2007.

9 Dr. Kirpal Singh, Automobile Engineering, Volume1.

72