INFLUENCES OF BRAKE SHOE THICKNESS AGAINTS DISC BRAKE VIBRATION SYSTEM ON Influences Of Brake Pad Thickness Againts Disc Brake System Vibration On Various Braking Condition.

INFLUENCES OF BRAKE SHOE THICKNESS
AGAINTS DISC BRAKE VIBRATION SYSTEM ON
VARIOUS BRAKING CONDITION
PUBLICATION ARTICLE

Submitted as a Partial Fulfillment of the Requirements for GettingBachelor
Degree of Engineering in Automotive Department

Arranged by :

Dwi Aji Saputra
NIM : D 200 102 012

MECHANICAL ENGINEERING PROGRAM STUDY
ENGINEERING FACULTY
MUHAMMADIYAH UNIVERSITY OF SURAKARTA
NOVEMBER 2014

INFLUENCES OF BRAKE SHOE THICKNESS AGAINTS DISC BRAKE VIBRATION
SYSTEM ON VARIOUS BRAKING CONDITION
Dwi Aji Saputra

Automotive Department of Muhammadiyah University of Surakarta
Jln. A. Yani Pabelan-Kartasura. Tromol Pos I Telp. (0271) 715448 Kartasura
Email: [email protected]
ABSTRACT
Abstract :
The aim of this study is to determine the condition of the brake vibration and analyze the
parameters that affect the vibration response occurring. Test was carried out by varying the
thickness of the brake lining. Data taken for thickness of the brake lining (7,5 and 3)mm, with
a variation of the braking pressure 0.6bar and 1bar, shaftrotation (425,

637, 850, and

1061)rpm, the axial and radial direction, vibration measurement used Lutron VB_8202
vibration meter.
Vibration on acceleration measurements show that vibration acceleration in the
radial direction which seems higher when compared to the axial direction, can be in the know
in the axial direction 425 RPM vibration acceleration value is not more than 8.2m / s while the
radial direction up to 11.6m/s .
Increasing the value of amplitude 2-4.7 m/s2 in dictateLessing of Brake pad
worn.The increase in vibration owing to the reduced value of brake lining.


Keywords :Brake, Brake lining thickness, Brake pressure, Damping.

discs (disc brake) with brake pads. These

Background
Brakes are an important component

friction

causes

vibration,

noise. Disc

stopping or slowing down. In general, the

factorstringer the vibration of brake pad and


vehicle uses hydraulic brake system. The

caliper.

caliper (cylinder

and

and

of motor vehicle. Brake function is to

Components of hydraulic brake are master

roughness

heat

friction


Vibration in the brake components

body).

during operation can cause noise. It comes

braking

from the friction between brake pads that

pressure from the pedal tocalipers (cylinder

have been worn by the disc brakes. One of

body) through

factors which cause the vibration when

cylinder


and

Cylinder

Master

distributes

the

brake

a

hose.

The

caliper (cylinder body) is usedto forward a


braking

hydraulic pressure to brake pad.

pad. The effects of excessive vibration will

operation

is

worn

thin

brake

using

cause inconvenience driving. In addition,


pressureprinciple to slow down the rotation

the vibration at brake pads has worn also

Brake

works

by

so that it reveals a friction between the

the performance or the operation of the

d. At the same braking pressure, the
frictional force is assumed to be the

braking was not optimal.
Brake pad is so extremely important
when braking. It needs special attention to


same

for

all

variations

in

the

thickness of the brake lining.

the condition of the brake pad. Therefore,
there should be a study to determine the
effect of thebrake pads thickness against
the brake disc vibration in the system.


The friction coefficient is assumed to be
the same on this test.
LITERATURE REVIEW
Oura (2009), conducted a research on

PROBLEM LIMITATION
From above explanation, it can be
taken a problem formulations, namely: how
to influence the thickness of the brake pads

the mechanism of the appearance of disc
brake squeal vibration.
Carried out research on testing squeal

on a range of braking conditions on the

vibration

vibration of the disc brake system.


thicknesses. The experiment was done with

using

Pads

with

different

testing equipment squeal by using brake

OBJECTIVE

pieces with size 20x20 mm with a thickness
The

purpose

of


this

study

is

determining the effect of the brake lining
thickness at various braking conditions on
the vibration disc brake system in the form
of changes in the value of the vibration
amplitude.

variation of the brake lining as testing
material.The experiment was conducted
with dynamic stiffness test apparatus which
was providing a constant pressure. The test
results showed the dynamic stiffness of
Pads became stiff when braking pressure
was increasing, and the stiffness increased

FORMULATION

with the thin Pads. Results of the testing
To determine the direction of research,
given the extent of the problem as follows:
a. All components of the braking device
is

assumed

to

be

at

calipers, discs and brake hoses).
conditions

are

considered

constant.
c. Data Display is only in the form of
vibration amplitude value.

when the stiffness of Pads became hard.
BASIC THEORY

normal

conditions (80% for the master,

b. Load

showed the frequency squeal was high

A. Brake Work System
In general, the brake discs are currently
working

to

apply

the

principles

of

hydraulics. The hydraulic system consists
of a master cylinder, brake calipers, brake
oil reservoir to place and other supporting
components. When we press

the handle

on brake master so piston inside brake

Brake is also a major component of the

master push fluid brake to fluid path, and

brake as it serves as a grappling discs so

then entering to piston chamber brake

that the rate of the vehicle can be reduced

caliper. At Outer Piston, brake pad is

and eventually stopped completely, usually

installed, this brake pad clamps disc brake

made of composite materials or pasta.

by using piston pressure to outer direction

Brake commonly used in today's modern

which is caused by the pressure of brake

vehicles is appropriate types of brakes,

fluid so that the friction effect among dsisc

whether wearing drum brake or disc brake.

and brake pad are generated braking

To canvass brake used in generally disc

process. Frictional forces that occur in the

brake pad or brake disc called a pad, while

disc braking system can be explained in the

used on drum brakes are often called brake

following figure:

shoe.

Figure 2. Brake Pad
Figure 1. How Disc Brakes Work
(Anonim, 2012)

b. Disc
In general, disc brake or disc made of
cast iron and holes for ventilation and

B. Disc Brake Components

In general, disc brake components

cooling function. Given the age of the brake
ventilation and longer lasting.

are as follows:
a. Brake Pad
Brake consists of a mixture of fiber and
little metallic iron powder. Generally brake
pad is given lining brake to show the thicks
of brake pad.Thus, the worn of the brake
can be checked easierwhen unloading

Figure 4. Disc

brake components. In some brake pads,
the use of metallic plate attached to the
side of the brake piston whose function is to
prevent noise when braking.

c. Caliper
Caliper is also called a cylinder body,
which

functions

holds-piston

and

the

channel where the brake fluid channeled to

the brake master cylinder of the caliper.

Vibration
Vibration is a back and forth motion

The components contained in the circuit

within

calipers as follows:

a

certain

Vibration

1. Piston

associated with the oscillatory motion of

2. Piston Ring

objects and force associated with these

3. Rubber Protector

objects. All objects that have mass and

4. Torque plate

elasticity is able to vibrate, so most
machines

The cause of the vibration on the brake
disc (brake pad)

and

Disk disc is not smooth
Disc Thickness
Unbalance disc
Worn disc Brake and Brake pad
Dust and dirt.

structural

and

consideration

of

design
the

friction between Brake pad and disc.

The magnitude of

vibration where the system generates a
that

of

the

we can see the

equation:
2

operation is vibration excited or self-excited

excitation

nature

2

Vibration happens on the brake during

of

requires

oscillation.

Brake force this optained from the

number

engineering

(engineering) experience some degree of
vibration

1.
2.
3.
4.
5.

interval.

Displacement deviation

can write

as:

produces

oscillatory motion in the system itself.

Harmonic motion velocity and acceleration

Numbers fnis one of the most important in

can

the amount of vibration analysis and is

equation

called the natural frequency. With the

derivatives, then ;

be

obtained
by

by

using

differentiation
dot

notation

equation to find the natural frequency of the
brake lining is:
/

With a record of angular frequency ω, with
units of radians per second, often used in
equations

because

it

simplifies

the

a. Free Vibration without damping

equations, but the amount is usually
converted into a frequency "standard"
(units of Hz) when stating the frequency of
the system.

Where :

0

of
for

deflection. The more rigid a structure
greater rigidity values.

k
b. Friction force

m

Friction is the force that is generated

x(t)

by two objects rub against each other and
the direction opposite to the motion of

F

objects. Here is the friction on the beam.

Figure 2.7. Vibration without dampers

With the equation to calculate the friction
force is:

b. Free Vibration with Dampig

Fg = .N

Where :
/

k

c

x(t)Figure 2.11 Friction on the beam

m

c. Damping
F

Damping is the absorption of incident
energy (energy dissipation) by a structure

Figure 2.8 Vibration with damping
Factors affecting the value of the
vibration on the brake

essential.

of

the

Restrictions

structure
are

is

an

useful

for

maintaining the rigidity of construction so
as not sagged more than the required
deflection. Stiffness is defined as the force
required

to

causes include the release of energy by
movement between molecules within the

a. Stiffness
Stiffness

due to various reasons. Some of the

obtain

one

unit

of

displacement. Stiffness value is the slope
angle of the relationship between load and

material, the release of energy by friction
linking devices and systems support, the
release of energy by friction in the air. The
energy release is also the result of plastic
joints. Since the damping function of
energy release then this will reduce the
structural response.
Therefore greatly affect the vibration
damping. Where the damping is strongly

influenced by the critical damping value

........................

(critical damping), the point at which the

RESEARCH METHODOLOGY

system no longer oscillates. The amount of

Flow chart diagram

attenuation is usually expressed in damping

START

ratio. The coefficient of damping required to
Making tool vibrations test

reach the point of critical damping is:

disc thickness brake Pad

2

2√

2

MAKING OF DATA

If the value of the damping coefficient to

Thickness Variation (A = 7, B = 5, C = 3) mm

reach the point of critical damping, then the

Braking Pressure Variation (0,6, and 1) Bar

system will be difficult muffled. So it is

Variations Rpm (425, 637, 850 and 1061)

difficult

to

stop

oscillating

system,
Acceleration value of

consequently a large vibration.

data vibrations

·
·



Analysis

·∆

Conclusion

·

END

k

F

F
Material and Tools
Tools wich used in this research are as



F

F

c

Page 2.12 Deflection axial
Where :


/

follows :
a. Brake pad vibration test equipment
(with electric motor 3 phase 5,5 HP)
b. 3 couple Brake pad with different
thickness (7mm, 5mm, 3mm).
c. Piezoelectric Accelerometer.
d. Vibration meter markLutronVB_8202
e. Tachometer.
f. Inverter.
g. Pulley dan bel

Data processing
p
s
step
Th
he first ste
ep of data
a processin
ng
begins with recorrd measurem
ment data in
on accelera
ation data into
the forrm of vibratio
a displlay table in the excel program. We
W
show the excel pro
ogram into a graph whicch
onnect betw
ween the brake linin
ng
we co
Figure 6. Vibration meter

thickne
ess variatio
on with rottation of th
he
motor and also brraking press
sure variatio
on
e rotation off the motor. Measurement
with the
of the natural
n
frequ
uency of the
e system eacch
brake lining thickkness variattion with th
he
ach
approa

we

c
calculate

the
t

continu
uous cantilevver beam rods.
A
er
Figure 7. Acceleromete

Figure8. Brake Pad

Affter the test is complete assembled
test, then performed the data collection,
which can be seen in
n the followin
ng
sccheme:

Figure 9.Test da
ata making schema
s

stiffnesss

Data And Analysis
Then, the data above are analized to

16

425

Thickness
7mm
8.2

Thickness
5mm
9.5

Thickness
3mm
10.2

637

10.8

12

12.8

850

12.8

13.7

15.3

1061

13

14.2

15.6

14
12

13.1

Vibration Velocity (m/s²)

16.2
15.4

15.2

14.8
13.2

11.1

Rotation
(RPM)

16.1

18

measurment shown at following figure :
RMS VALUE (m/s2)

pressure and shaft rotation speed. Data

17.1

Vibration Graphs on axial
direction for pressure 1 bar

knowing the vibration at different brake

11.2

10.7

10
8

Pad 7
8.9

Pad 5

6

Pad 3

4
2
0

Vibration Graphs on axial
direction for pressure 0.6 bar

425 637 850 1061 RPM

18

8

15.6
14.2
13

15.3
13.7
12.8

12

10.2

rotations of the vibration amplitude in the
axial direction, the braking pressure of 1bar

10.8

10

9.5

12

12.8

14

Figure 11. Relationship between the axis

Pad 7
Pad 5

8.2

RMS VALUE (m/s2)

16

Rotation
(RPM)

4

425

Thickness
7mm
7

2

637

9

11.2

12.7

0

850

11.8

12.9

14.5

1061

13.5

14.6

16.1

6

Pad 3

425 637 850 1061

Thickness
5mm
9.5

Thickness
3mm
11.6

RPM

Vibration Graphs on Radial
direction for pressure 0.6 bar

Figure 10. Relationship between the

the axial direction, the braking pressure of
0.6bar
Vibration Velocity (m/s²)

425

Thickness
7mm
8.9

Thickness
5mm
10.7

Thickness
3mm
11.1

637

11.2

13.2

13.1

850

14.8

15.4

16.1

1061

15.2

16.2

17.1

RMS VALUE (m/s2)

rotation axes of the vibration amplitude in

Rotation
(RPM)

Vibration Velocity (m/s²)

20
18
16
14
12
10
8
6
4
2
0

18.1
16.5
14.7
13.6
13.2

14.9

16.6
15.5

13.8

11.5

Pad 7

11

Pad 5

9

Pad 3

425 637 850 1061

RPM

Figure 12. The relationship between the

the processing vibration indication that the

rotation axis of the vibration amplitude in

brake pads are still good or still thick

the radial direction at a pressure of 0.6bar
Rotation
(RPM)

produces low vibration acceleration value.
From vibration value measurment, we

Vibration velocity (m/s²)
Thickness

Thickness

Thickness

can find the value of brake pad natural

7mm

5mm

3mm

frequency and critical damping coeficient

425

9.6

12.5

14.3

which will get result as table below:

637

12.2

15.7

16

850

16.5

17.2

17.5

Table 1. Values of natural frequencies and

1061

17.3

18.3

19.2

critical damping coefficient value of each
brake pad.

Vibration Graphs on Radial
direction for pressure 1 bar

Thick Brake
Pad (mm)

RMS VALUE (m/s2)

25
20

(Ns/m)

7

493,63

184,61

5

1111,94

373,27

3

4447,92

1352,16

19.2
17.5
16

15

(Hz)

14.3
12.5

17.2

18.3
17.3

16.5

15.7

Pad 7

12.2

Pad 5

10
9.6

Based on the results of these calculations
with a critical damping coefficient is greater,

Pad 3

and the system will easily vibrate because

5

of small damping ratio.
0
425

637

850

On

1061 RPM

the

axial

direction

of

the

measurement pressure of 1 bar (Figure 4.2)
Figure 13. Relationship between the axis

and the measurement of radial pressure of

rotations of the vibration amplitude in the

1 bar (Figure 4.4) it can be seen that the

radial direction at a pressure of 1bar

thickness of the lining 5mm shaft speed
637 rpm surge approaching the vibration

Discussion

amplitude values even exceed the value of

The results of processing the vibration

the amplitude of vibration in the lining

an

thickness of 3mm.On the measurement of

increase in the value of the acceleration of

vibration velocity shows that the vibration of

vibration generated each variation of the

velocity

thickness of the brake lining. This increase

appears larger when compared to the axial

is indicated by the value of the acceleration

direction, as shown in the graph measuring

of vibration that occurs in brake that has

the axial direction for the braking pressure

experienced wear and worn. The results of

0.6 bar (Figure 10) and radial graphs for

acceleration

values

indicate

that

in

the

radial

direction

which

braking pressure 0.6 bar (Figure 12) it can

Untuk selanjutnya dapat di lakukan

be seen the difference value of the

penelitian untuk mendeteksi tingkat

resonance. 425 rpm for shaft rotation in the

keasuan

direction of axial value does not exceed 8.2

dengan bahan atau merk yang

m/s2, while in the radial direction vibration
reaches the value of 11.6 m/s2. This occurs
due to the effect of centrifugal force on the
rotation axis to the radial direction, so that
the force that occurs on the radial direction
is greater than the axial direction.
Conclusion
From data analysing and discusion can be
of tained conclusion as follow :
1. Increasing the value of aplitude2-4,7
m/s2in dicate lessing of Brake pad
worn.The increasing of aplitude value is
cause by the lessing of pad mass, that
affect the decreasing of damping value
to vibration, then Increasing of braking
pressure and shaft rotation will increase
exitation force that cause the value of
amplitude greater.
Sugesstion
1. Next, we can do research to detect the
level of brake pad worn using other
brand.
2. Before take the data, it is better to know
the brake resonansi frequency.
Sugegestion

kampas

rem

cakram

berbeda.
Sebelum
henaknya

pengambilan
mengetahui

resonansi sistem.

data
frekuensi

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