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Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
1
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
ANALYSIS AND PERFORMANCE IMPROVEMENT OF A DISC
BRAKE REPLACING TRADITIONAL MATERIAL GREY CAST IRON
IN ANSYS
Haider Ali Naqvi1, Josy George
2, Mukesh Sahu
3
Assistant Professor, Department of Mechanical Engineering, Lakshmi Narain College of
Technology, Bhopal
Declaration of Author: I hereby declare that the content of this research paper has been truly made by me including the title of the research paper/research article, and no serial sequence of any sentence has been copied through internet or any other source except references or some unavoidable essential or technical terms. In case of finding any patent or copy right content of any source or other author in my paper/article, I sha ll always be responsible for further clarification or any legal issues. For sole right content of different author or different source, which was unintentionally or intentionally used in this research paper shall immediately be removed from this journal and I shall be accountable for any further legal issues, and there will be no responsibility of Journal in any matter. If anyone has some issue related to the content of this research paper’s copied or plagiarism content he/she may cont act on my above mentioned email ID.
ABSTRACT
In today’s developing automobile sector, there is drastic change in the technology from
transmission system to braking system. The braking system is considered as one of the most
important system from performance as well as safety point of view. When the brakes are
applied to the moving vehicle, all the kinetic energy of the vehicle gets converted into
equivalent amount of heat generation.
The aim of this research work is to choose best material which is light in weight and fulfill all
design requirements. The model of disc is created in CATIA V5 while the analysis is
conducted in ANSYS 19.0. The analysis performed in ANSYS is steady static structural.
Keywords –Static structural analysis, Finite Element Method, Disc Brake, ANSYS etc
I. INTRODUCTION
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. In the process of
performing this function, the brakes absorb
either kinetic energy of the moving
member or the potential energy given up
by objects being lowered by hoists,
elevators etc. The energy absorbed by
brakes is dissipated in the form of heat.
This heat is dissipated in the surrounding
atmosphere to stop the vehicle, so the
brake system should have following
requirements:
The brakes must be strong
enough to stop the vehicle with
in a minimum distance in an
emergency.
The driver must have proper
control over the vehicle during
braking and vehicle must not
skid.
The brakes must have well anti
fade characteristics i.e. their
effectiveness should not
decrease with constant
prolonged application.
The brakes should have well
anti wear properties.
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
When hydraulic pressure is applied to the
caliper piston, the pressure tends to exert a
force on the caliper which results in
squeezing the disc between two friction
surfaces of the disc. Since disc brakes do
not use friction between the lining and
rotor to increase braking power as drum
brakes do, they are less likely to cause a
pull. As most of the portion of the disc
brake is exposed to the surrounding, there
is best heat dissipation rate which gives
faster cooling of the disc brake disc. This
phenomenon plays an important role in
minimizing the brake fade. It also allows
for self-cleaning as dust and water is
thrown off, reducing friction difference.
A. PROBLEM OCCURRED IN DISC
BRAKE
Discs are made up mainly gray cast iron,
so discs are damaged in one of three 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 workers to
resurface the original 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. 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 maximize the mileage out of the
current discs on the vehicle. Braking
systems rely on friction to bring the
vehicle to a halt – hydraulic pressure
pushes brake pads against a cast iron disc
or brake shoes against the inside of a cast
iron drum. When a vehicle is decelerated,
load is transferred to the front wheels –
this means that the front brakes do most of
the work in stopping the vehicle. Scarring
can occur if brake pads are not changed
promptly when they reach the end of their
service life and are considered worn out.
II. LITERATURE REVIEW
Swapnil.D.Kulkarni (2017)research in
disc brake is the recent trend in automobile
vehicles which dissipates the heat faster
than the conventional drum brakes. but if
hard braking is done, there is induction of
thermal stresses in the brake disc which
leads to generation of excessive
temperature .if this heat is not dissipated
properly, then distortion will be get
produced in the disc which leads to
thermal cracking of the disc leading to disc
failure. The brake disc has an inherent
ability that there is no change of co-
efficient of friction on the disc so there is
no problem of brake fading phenomenon.
The main advantage of disc brake is that
only a small portion of the disc is in
contact with the friction material i.e. the
caliper. Hence there is large surface area
of the disc which can dissipate the heat to
the atmosphere. Specifically the heat
dissipated to the atmosphere is the forced
convection mode. The aim of this research
work is to choose best profile and best
material which can dissipate maximum
amount of heat to the surrounding.
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
Prof. Mit Patel (2016) study in
optimization of technical aspects in
automobile is very important and
necessary as there are large numbers of
vehicles running on road today, so that
part or product will be durable, safe and
affordable to the users. The brakes are
very important aspects of a vehicle as it
fulfils all the stopping functions and
requirements. As brakes have to undergo
through continuous use, many issues
surround their heating characteristics when
it comes to their development, including
contact region properties, material choice,
development of hot spots, associated
physical geometry, and deformations. The
main purpose of this study is to analysis
the thermo-mechanical behaviour 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 to
enhance performance of the rotor disc. A
comparison between analytical and results
obtained from FEA is done and all the
values obtained from the analysis are less
than their allowable values. Hence best
suitable design, will be suggested based on
the performance, strength and rigidity
criteria.
C. Radhakrishnan P (2015) said that disc
brake is a device by means of which
artificial frictional resistance is applied to
rotating disc, in order to stop the motion of
vehicle. During the braking phase, the
frictional heat generated at the interface of
the disc and pads can lead to high
temperatures. The frictional heat generated
on the rotor surface can influence
excessive temperature rise which, in turn,
leads to undesirable effects such as
thermal elastic instability (TEI), premature
wear, brake fluid vaporization (BFV) and
thermally excited vibrations (TEV).This
causes will be reduced by better thermal
stability materials. In this project we
analyze the thermal behavior of the
ventilatedbrake disc with Titanium alloy
(Ti 550) and conventional grey cast iron
material in finite element software ANSYS
WORKBENCH 14.0. Modeling of the disc
brake rotor is done using SOLIDWORKS
2013.Finally a comparison is made
between conventional grey cast iron and Ti
550 materials and the best material for
making disc brake have been suggested
based on the magnitude of Von misses
stresses, temperature distribution and
deformation from the thermal analysis
result.
Swapnil R. Abhang (2014)said that 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 braking 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
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
material, how disc brake works more
efficiently, which can help to reduce the
accident that may happen in each day.
N. Balasubramanyam (2014)study in
transient analysis for the thermo elastic
contact problem of the disk brakes with
heat generation is performed using the
finite element analysis. To analyze the
thermo elastic phenomenon occurring in
the disk brakes, the occupied heat
conduction and elastic equations are
solved with contact problems. The
numerical simulation for the thermo elastic
behavior of disk brake is obtained in the
repeated brake condition. The
computational results are presented for the
distribution of heat flux and temperature
on each friction surface between the
contacting bodies. Also, thermo elastic
instability (TIE) phenomenon (the unstable
growth of contact pressure and
temperature) is investigated in the present
study, and the influence of the material
properties on the thermo elastic behaviors
(the maximum temperature on the friction
surfaces) is investigated to facilitate the
conceptual design of the disk brake
system. Based on these numerical results,
the thermo elastic behaviors of the carbon-
carbon composites with excellent
mechanical properties are also discussed.
III. OBJECTIVE
The brakes are one of the most important
control components of vehicle. They are
required to stop the vehicle within the
smallest possible distance and this is done
by converting the kinetic energy of the
vehicle into the heat energy which is
dissipated into the atmosphere.
The main objective of this study to
introduce new material on the disk brake
by replacing traditional material (Gray cast
iron) and increase the overall performance
of the disk brake.
IV. METHODOLOGY
When a brake lever or pedal is
pressed, the push rod which is connected
to lever or pedal and master cylinder
piston pushes the master cylinder piston.
This movement allows the master cylinder
piston to slide and push the return spring
inside the bore of master cylinder, which
generates pressure in reservoir tank. At
this moment a primary seal allows the
brake fluid of reservoir tank to flow over it
into the brake hosepipes. A secondary seal
ensures that the brake fluid does not go
other side. Then the fluid enters in to
cylinder bore of caliper assembly via brake
hosepipes and pushes the caliper piston or
pistons. At this time the piston ring moves
in rolling shape with piston. Then the
caliper piston pushes brake pad. This
movement causes brake pads to stick with
brake disc which creates friction and stops
the brake disc/rotor to rotate. This way
disk brake system stops or slows down the
vehicle.
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Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
6
Fig. 1 Working of Disc Break
When the brake lever or pedal is released
the piston ring pushes the caliper piston
back to cylinder bore of caliper till both,
caliper piston and piston ring come into
their original shape. At this time retraction
spring pushes the brake pads to their
original position. The return spring in
master cylinder assembly pushes the
master cylinder piston back into its
original position and allows the fluid to
flow back to reservoir via hosepipe and
master cylinder bore.
A. DESIGN CALCULATION
1) The brake pedal:
Brake pedal is an mechanical component
used in the brake system of motor cycles
and cars where the driver foot is used for
applying the pressure to stop the vehicle in
the running condition. In this system the
increase in force is always equal to the
multiplication of lever ratio used in the
levels of the brake pad assembly.
Fbrake pedal = Fd × [L1 / L2]
Where,
Fbp = the force output of the brake
pedal assembly
Fd = the force applied to the pedal
pad by the driver = 370 N
L1 = the distance from the brake
pedal arm pivot to the output rod clevis
attachment
L2 =the distance from the brake
pedal arm pivot to the brake pedal pad
(L1/L2 = 4)
The incompressible liquid is assuming in
master cylinder of disk brake and its fixed
hydraulic vessels, the pressure calculation
of master cylinder will be denoted in
formula
𝑃𝑚𝑐 =𝐹𝑏𝑝𝐴𝑚𝑐
Where
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
Pmc= the hydraulic pressure
generated by the master cylinder.
Amc= the effective area of the
master cylinder hydraulic piston =
0.000285 m2.
Brake fluid, brake pipes and hoses:
Assuming no losses along the length of the
brake lines, the pressure transmitted to the
calipers will be equal to:
Pcal = Pmc
Where,
Pcal= the hydraulic pressure
transmitted to the caliper.
The rotor: This torque is related to
the brake pad frictional forceas follows:
Tr= Ffriction× Reff
Where,
Tr= the torque generated by the
rotor.
Reff= the effective radius (effective
moment arm) of the rotor (measured from
the rotor center of rotation to the center of
pressure of the caliper pistons).
This torque generated by the rotor
will be equal to the torque required to stop
the vehicle. In this report, they follow
Mass of the vehicle = 300
kg.
Maximum velocity of the
vehicle = 80 km/hr or 22.22
m/s.
Stopping Distance = 11.69
m.
Tire Size = 23 in diameter
that is 584.2 mm with 7
mm thickness
Disc flange or thickness =
16 mm.
50-50 wheel bias that is
equal braking force is
generated in all the 4
wheels of the vehicle.
Total force generated during
braking to stop the car,
F = m×a, a = deceleration during
braking = v2/2s = 22.222/2 x 11.69= 21.12
m/s2
F= 300 x 21.12
F= 6336 N.
Torque required stopping the
vehicle,
Tr= F/4 ×Rw
Tr= 6336/4 x 0.2921
Tr= 462.54 N-m.
As mentioned in above formulae,
Fbp= Fd× (L1/L2)
Fbp= 370 x 4
Fbp= 1480 N.
P = Fbp/Amc
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Pmc= 1480/0.000285
Pmc= 5192982.456 Pa
Pmc= Pcal= 5192982.456 Pa
Fcal= Pcal ×Acal
Fcal= 5192982.456 x 0.0007068
Fcal= 3670.4 N.
Clamping Force = 2Fcal.
Fclamp= 7340.8 N.
Ffriction= Frictional force
generated on the rotor during
brakingprocess,
Ffriction= 7340.8 × 0.4
Ffriction= 2936.32 N
Torque generated by the rotor
during braking = Ffriction×Reff= 462.54
Therefore, the effective rotor radius
Reff= 0.1575 m.
Thus, the Effective Rotor Radius is
0.1575 meters that is 6.2 inches or 157.5
mm. And thus, the effective diameter is
315 mm.
Based on this effective diameter,
the outer diameter of the disc isdecided to
be 381 mm and the inner diameter to be
125 mm.
Kinetic Energy developed during
braking,
KE = ½ mv2
KE = ½ x 300 x (22.22)2
KE = 74059.26 J
B. PROCEDURE FOR ANSYS
ANALYSIS
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 nonlinear. 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.
C. MATERIAL PROPERTIES
There are two material are used in
analysis one is gray cast iron and second is
aluminium 2014-T6, the general property
of material are as follows:
Table 1: Material Properties of gray cast iron and aluminium alloy.
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
Gray cast iron Aluminium
2014-T6
Density (kg/m3) 7200 2400
Young’s Modulus (GPa) 125 4270
0
Poisson’s ratio 0.25 0.33
D. STEPS OF ANSYS ANALYSIS
The different analysis steps involved in
ANSYS are mentioned below.
1) Pre-process
The model setup is basically done in pre-
processor. The different steps in pre-
processing are
2) Building the model
The CATIA provides the following
approaches for model generation: Creating
a solid model within CATIA. Every design
starts with the conventional calculations by
applying various fundamentals of design.
The basic model of disk brake is creating
in following step.
Fig. 2: Final base model of Disk brake in Catia
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Fig. 3 Sketch of Basic Disk Brake model
E. Meshing
ANSYS Meshing includes intelligent,
general-purpose, automated high-
performance type of product. It delivers
the most suitable work for exact, proficient
Multi physics arrangements. A work
appropriate for a particular investigation
can be created with a solitary mouse click
for all parts in a model. For the master
client who needs to tweak on it give full
controls over the alternatives used to
create the work are accessible. The energy
of parallel preparing is consequently used
to decrease the time you have to wait for
mesh generation.
Creating a mesh in the imported geometry
is an important step in ANSYS analysis as
the size of the finite element is decided by
the mesh properties. Finer the mesh is,
more accurate are the results.
After the given meshing in ANSYS the
number of element is 13888 and number of
Nodes is27527
.
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Volume XV, ISSN: 2320-3714
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Fig 4: Meshing of base model
Table 2: Nodes & Element
Number of Nodes 1574
5
Number of
Elements
7753
F. BOUNDARAY CONDITION
The next step in the static structural
ANSYS analysis is to apply the boundary
conditions. All six hole are fixed in
applying fixed support and the after
applying a force, this force are applying in
disk brake in to opposite surfaces of disk
brake. The total applying force is 2936.32
Newton is apply in top and bottom of disk
brake. The above analysis is study in total
deformation equivalent stress and strain
analysis. Giving 27.63 rpm rotational
velocity for disk brake by clockwise
direction run calculation and monitoring
the solution. Since Also since the disc has
to be fixed at its centers, fixed supports are
given to the hub bolts and the inner portion
of the entire inner circle. Thus, overall
there are 4 initial boundary conditions
given to the disc rotors model or geometry
before proceeding to the solution.
Fig. 5 Boundary condition
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
V. RESULT
A. ANSYS analysis of Gray cast iron disk brake
Fig. 6: Total deformation of Gray cast iron disk brake
Fig. 7 Equivalent stress of Gray cast iron disk brake
Airo International Research Journal August, 2018
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Fig. 8 Strain of Gray cast iron disk brake
B. ANSYS analysis of Aluminium alloy disk brake
Fig. 9: Total deformation of Aluminium alloy disk brake
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Fig. 10 Equivalent stress of Aluminium alloy disk brake
Fig. 11 Strain of Aluminium alloy disk brake
C. Comparison deformation of disk brake
The maximum deformation of Gray cast iron disk brake model is 1.2437e-6 m and
total deformation of aluminium alloy model is 2.1379e-9m
Table 3 Result of deformation
Disk brake model Deformation
(m)
Base model 1.2437e-6
Aluminium model 2.1379e-9
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
Impact Factor 0.75 to 3.19
Graph 1 Comparison deformation
D. Comparison Equivalent stress of disk brake
The maximum equivalent stress of Gray cast iron disk brake model is 4.2158e6 Pa
and equivalent stress of Aluminium alloy model is 4.2187e6 Pa.
Table 4: Result of Equivalent stress
Disk brake model Equivalent stress
(Pa)
Gray cast iron 4.2158e6
Aluminium alloy 4.2187e6
Base Model Aluminium Model
Deformation (m) 1.24E-06 2.14E-09
0.00E+00
2.00E-07
4.00E-07
6.00E-07
8.00E-07
1.00E-06
1.20E-06
1.40E-06D
efo
rmat
ion
Deformation (m)
Airo International Research Journal August, 2018
Volume XV, ISSN: 2320-3714
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Graph 2 Comparison Equivalent stresses
E. Comparison Strain of disk brake
The maximum Strain of disk brake base model is 3.778e-5 and Strain of aluminium model is
5.8354e-8
Table 5 Result of Strain
Disk brake model Strain (m/m)
Gray cast iron 3.778e-5
Aluminium alloy 5.8354e-
8
Gray cast iron Aluminium alloy
Equivalent stress (Pa) 4.22E+06 4.22E+06
0.00E+00
1.00E+06
2.00E+06
3.00E+06
4.00E+06
5.00E+06Eq
uiv
ale
nt s
tre
ss
Equivalent stress (Pa)
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Volume XV, ISSN: 2320-3714
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Graph 3 Comparison strain
F. Comparison Weight of disk brake
The Weight of Graycas iron disk brake model is 5761.3 Kg and weight of Aluminium alloy
model is 2.2405Kg.
Table 6: Result of Weight
Disk brake
model
Weight
(gm)
Gray cast iron 5.7613
Aluminium alloy 2.2405
Gray cast iron Aluminium alloy
Strain (m/m) 3.78E-05 5.84E-08
0.00E+00
5.00E-06
1.00E-05
1.50E-05
2.00E-05
2.50E-05
3.00E-05
3.50E-05
4.00E-05
Stra
inStrain (m/m)
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Graph 4 Comparison Weight
VI. CONCLUSION
Structural analysis is done on disc rotor for
two materials Gray cast iron and
Aluminum alloy. A present used material
for disc brake is Gray cast iron. We are
replacing the material with Aluminum
alloy, since its density is less than that of
Gray cast iron thereby reducing the weight
of disc brake. By observing the stress
values obtained in structural analysis, they
are less than the yield stress value of
Aluminum alloy, so using Aluminum alloy
for disc brake is safe. So using Aluminum
alloy is better. Reducing weight of disc
rotor, Braking system becomes less bulky
and compact. Moreover, with increased
weight braking force also increases, hence
weight reduction can result is effective
performance of disc brake.
Failure criteria of disc brake rotor is
equivalent stress, for both Aluminum as
well as Gray cast iron equivalent stress is
less than ultimate strength hence both
design are safe. But weight of Gray cast
iron is more than that of Aluminum, hence
to reduce weight of disc brake rotor it
should be made of Aluminum alloy.
VII. REFERENCE
[1] Swapnil.D.Kulkarni, J.J.Salunke
(2017) “THERMAL ANALYSIS
OF BRAKE DISC” IJRET:
International Journal of Research
in Engineering and Technology
eISSN: 2319-1163 | pISSN: 2321-
7308Volume: 06 Issue: 02
[2] Prof. Mit Patel, MansiRaval, Jenish
Patel (2016) “Design of Disc
Brake’s Rotor” International
Journal of Engineering
Development and ResearchVolume
4, Issue 4 | ISSN: 2321-9939
[3] C.RadhakrishnanP,
P,Yokeswaran.KP, P,
Vengadeshprasadh.MP,
Gray cast iron Aluminium alloy
Weight (Kg) 5.7613 2.2405
0
1
2
3
4
5
6
7W
eigh
tWeight (Kg)
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Volume XV, ISSN: 2320-3714
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P,Vishnuhasan.AP, P, Vimalraj.TP,
P, Velusamy.MP (2015) “DESIGN
AND ANALYSIS OF DISC
BRAKE WITH TITANIUM
ALLOY” IJISET - International
Journal of Innovative Science,
Engineering & Technology, Vol. 2
Issue 5
[4] Swapnil R. Abhang#1,
D.P.Bhaskar (2014) “Design and
Analysis of Disc Brake”
International Journal of
Engineering Trends and
Technology (IJETT) – Volume 8
[5] N. Balasubramanyam, Prof. Smt.
G. Prasanthi (2014) “Design and
Analysis of Disc Brake Rotor for a
TwoWheeler” International Journal
of Mechanical and Industrial
Technology (IJMIT)Vol. 1, Issue 1,
pp: (7-12)