IRJET - Design, Simulation and Analysis of Double Wishbone Suspension System for an All-Terrain Vehicle (ATV)

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 07 Issue: 04 | Apr 2020 www.irjet.net p-ISSN: 2395-0072
© 2020, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 380
DESIGN, SIMULATION AND ANALYSIS OF DOUBLE WISHBONE
SUSPENSION SYSTEM FOR AN ALL-TERRAIN VEHICLE (ATV)
Rushikesh Kumbhar1, Aadesh Shinde2, Rushikesh Kharat3, Ashutosh Kumbhar4
1,2,3,4Student, Mechanical Engineering, RMD Sinhgad School of Engineering, Maharashtra, India
---------------------------------------------------------------------***----------------------------------------------------------------------
Abstract - In an All Terrain Vehicle (ATV), the suspension
system plays an essential role and contributes towards the
isolation of heavy vibrations in a system. The primary
function of the suspension system is to absorb the shocks
coming constantly from the bumps and maintains
comfortable contact between an ATV and road. This paper
deals with the design, optimization, analysis and simulation
of the front double wishbone suspension system for an All
Terrain Vehicle. The double wishbone suspension system
provides balanced stability under dynamic conditions.
Considering various forces, cornering effect, camber and
castor angle, king pin inclination, roll steer, scrub radius, etc
acting on the tire, optimized suspension system is designed,
analyzed and simulated for effective performance of an ATV.
Use of A-type hollow metallic arms for front suspension is
provided for weight reduction. The geometry is sketched
with the use of CATIA V5. Various parts like hub, knuckle,
control arms, etc are designed on CATIA V5 and modeling
geometry is imported in ANSYS for structural analysis.
Material optimization is focused for stress and deformation
results within FOS limit. The simulation of the system is
tested on MSC ADAMS software. Finally, after producing
different parts for front suspension, testing and validation is
implemented for effective performance and overall weight
reduction of an ATV.
Key Words: Roll Centre, load transfer, camber, toe,
knuckle, wheel hub
1. INTRODUCTION
All Terrain Vehicles are basically known as quad bikes or
quadric-cycles. The important quality of an ATV is to
travel on low pressure tires along any type of terrain with
single driver operating handlebars or circular wheel for
steering control. In an ATV system, the double wishbone
suspension system is one of the types of an independent
suspension system usually using two parallel wishbones
locating one end on knuckle and another end to vehicle
chassis frame. Shock absorber is mounted on upper or
lower wishbone depending on simulation result which
isolates the bump vibrations inducing in a vehicle. The
maximum travel, camber, roll centre height, anti-dive and
anti-squat are major aspects related to suspension system
which are important for an ATV.. The main perspective of
suspension system is to provide better steering handling,
vehicle stability and maintain comfort for passengers by
absorbing the bumps. Forces like lateral, longitudinal,
cornering and vertical forces are acted through tires. The
motive of an upright or knuckle assembly is to provide a
physical mounting and links from the suspension arms to
the hub and wheel assembly which carries braking
components. It is a load-bearing member of the
suspension system and is constantly rotating with the
motion of the wheel. Various materials are opted for
design considerations and sustainability throughout the
racing track. Optimization is done at several steps for
weight reduction. The primary objective of the double
wishbone suspension system is to achieve effective
performance to the total weight ratio of the vehicle.
1.1 Objective
The basic goal of the paper is to design double wishbone
system which can endure the hard terrains with
suspension travel of 3 inch for bump and rebound each
considering significant cornering speed.
1.2 Methodology
 Determination of optimised Roll Centre
Geometry using Adams Car Simulation
Software.
 Design of components Software such as
Wishbone, Knuckle, Wheel hub on the basis of
optimised Roll Centre Geometry.
 Analysis of Designed components using Ansys
Workbench Software.
1.3 Basic Parameters
 Track width = 1220 mm (48 inch)
 Wheelbase = 1168 mm (16 inch)
 CG Height = 330 mm (13 inch)
 Static Camber Angle = 0°
 Static Toe Angle = 0°
 King Pin Inclination = 8.5°
 Centre Offset = 62 mm
 Design Weight of Vehicle = 250 Kg
 Weight Distribution = 40:60 (Front : Rear)

2. ROLL CENTRE GEOMETRY
Roll centre is the imaginary point about which the vehicle
rolls in dynamic condition. There are certain
methodologies to determine the height of roll centre in
suspension system. Locating the static position of roll
centre in suspension geometry plays the pivotal roll as it
further determines the lengths of wishbones, total height of
knuckle, position of steering arm, length of tie rod, etc.
After determining the position of roll centre, the respective
geometry is simulated in Adams Car Simulation Software.
Geometry providing the precise simulation results is
further considered as optimized roll centre geometry.
Procedure for locating roll centre for double wishbone
suspension system is explained below.
2.1 Determination of Roll Centre
Fig -1: Determination of Roll Centre
Above figure explains the basic course of action to
determine the roll centre. As it can be seen from the figure,
it is solely dependent on suspension geometry as well as
basic principle of Instantaneous centre. Initially, the ICR
(instantaneous centre of rotation) of suspension arms i.e.
wishbones is located through which imaginary line from
wheel contact patch is passed. The point of intersection of
this line and vehicle centre axis defines the static roll
centre of the given suspension geometry. Furthermore it
should be noted that, relative distance between the Roll
Centre and Centre of Gravity (C.G) directly affects the
magnitude of jacking force induced.
Fig -2: Roll Centre Geometry
2.2 Simulation of Roll Centre Geometry
After plotting the RC geometry, kinematic simulation is
performed using MSC Adams Car Software to find out
whether the designed system provides the optimized
results or not. MSC Adams software provides good
simulation platform for the user giving specific graphical
outputs for the various dynamic input conditions.
Hard-points of several suspension locations are entered in
Adams software which further generates the 3D model of
designed suspension geometry. Basic parameters such as
vehicle weight, weight distribution ratio, CG height, static
wheel parameters (camber and toe angle) must be
provided in the iteration before performing the final
simulation as it affects the performance of a vehicle in
dynamic condition.
Fig -3: Suspension model in ADAMS
Simulation results can be obtained in the graphical form
for different wheel parameters such as camber, caster, toe,
ride rate against wheel travel. It is important to note that,
dynamic change in the wheel parameters should be
minimum for better handling performance and less tire
wear.
Chart -1: Camber Angle VS Wheel Travel
It can be seen from the results that, dynamic change of the
camber angle and toe angle against wheel travel is within
limit. Hence, the respective RC Geometry should be
considered as optimized one for the further design.

Chart -2: Toe Angle VS Wheel Travel
Following are the important parameters which are
obtained from Optimized Roll Centre Geometry.
Table -1: Obtained Parameters
3. MATERIAL SELECTION
Material Selection plays an important role in given design
and analysis as selected material should satisfy the design
criteria. Additionally, maximum and minimum stress
induced in the dynamic loading condition should also be
within factor of safety limit. Material mainly used for
manufacturing of wheel assembly i.e. Knuckle and hub are
Mild steel and Aluminum. Factor of safety while designing
these suspension components should be considered
between 1 to 2.5 for given material. There are other
factors such as cost, availability, weight which should also
be considered while selecting the appropriate material.
3.1 Material Selection for Wishbone
Wishbones are the connecting link between wheel
assembly and chassis of a vehicle. Thus, dynamic lateral
load transfer induced while cornering acts directly
through these suspension links. Hence, wishbone must
sustain these dynamic loading conditions before structural
failure. This factor should be considered while selecting
the material for wishbones.
According to market availability of different materials,
grades AISI 1018, AISI 1020, AISI 4130 are shortlisted for
material selection amongst which grade AISI 1020 with
outer pipe diameter of 22 mm having 1.6 mm thickness is
selected for wishbones considering yield strength.
Table 2 -: Material Comparison for Wishbone
3.2 Material Selection for Wheel Assembly
Wheel assembly mainly consists of knuckle, stub axle,
brake disk, caliper mounting and wheel hub. As the scope
of this paper is limited to knuckle and hub, we will select
material for the same by performing similar material
comparison as earlier.
Hub is one of critical part of the wheel assembly
connecting tires and brake disk on either end. It sustains
static forces such as wheel reaction, distributed vehicle
weight as well as dynamic loading such as lateral load
transfer, longitudinal load transfer, braking torque and
bump forces. These forces are further directed towards
knuckle through the stub axle which is accountable for
holding the wheel assembly together. Because of this
reason, vehicle hub and knuckle should be made of the
material having high ultimate tensile strength with factor
of safety more than 1.5.
Table 3 -: Material Comparison for Wheel Assembly
Parameter Value
Length of Upper Wishbone 246 mm
Length of Lower Wishbone
282 mm
Centre to Centre Height of Knuckle
140mm
Position of Steering Arm on Knuckle
(from centre of upper ball joint
mount)
60 mm
Length of Steering Tie Rod
395 mm
Material
Properties
Al 6061 Al 7071 EN 24
Yield Strength
(MPa)
310 572 1000
Ultimate Tensile
Strength (MPa)
276 503 680
Hardness (BHN) 95 150 302
Modulus of
Rigidity (GPa)
68.9 71.7 207
Material
Properties
AISI 1018 AISI 1020
AISI
4130
Yield Strength
(MPa)
440 394 560
Ultimate Tensile
Strength (Mpa)
370 294 460
Hardness (BHN) 126 111 217
Modulus of
Rigidity (GPa)
205 200 210

Considering all above factors along with criticality of
components, Al 7071 is selected for wheel assembly
providing highest tensile stress with high weight to
performance ratio.
4. DESIGN AND ANALYSIS
Design mainly includes force calculation as follows:
 Cornering Force –
It is calculated using Newton’s Second Law of
Motion and acts in radially outward direction on
wheel assembly.
Consider, vehicle is cornering at 45 KMPH
(12.5 m/s) with track turning radius of 2.6 m,
then cornering force induced on inner tire is given
by,
Substituting above values we get,
Fc = 6010 N
Above equation gives the magnitude of cornering force
acting on inner wheel of the vehicle. Definite percentage of
this force is transferred dynamically to outer tire in lateral
direction. This is called as dynamic lateral load transfer. It
is calculated by
( ) ( ) ( )
( )
It can be seen in above equation, product of lateral
acceleration and mass gives the value of Cornering force
calculated earlier. Thus, substituting values in above
equation we get,
Load Transfer = 1626 N
This simply implies that, under steady state condition,
1626 N of the load on the inside tire is transferred laterally
to outside tire achieving dynamic lateral load transfer of
27 %. It should be noted that, load transfer is mainly
calculated to check the feasibility of the suspension system
under dynamic condition. However, cornering force
calculated earlier must be used while performing the static
structural analysis.
 Bump Force –
It is calculated using principle of change in kinetic
energy. It is given by,
Change in KE = Work Done
Consider, the vehicle accelerating from rest
position achieving the final velocity of 45 KMPH
(12.5 m/s) at the instance of 6ft (1.82 m) bump
i.e. displacement,
FBump = 10684 N
 Force on Steering Arm –
It is the product of static wheel reaction and that
of coefficient of friction.
Consider, wheel reaction distributed according to
weight distribution ratio and coefficient of friction
of 0.6 we get,
Force = 0.6 × 0.4 × 250 × 9.81
2
Force = 294.3 N
This represents the magnitude of force acting
through steering arm for single knuckle.
 Brake Torque –
It is simply the product of braking force (N) and
effective wheel radius (mm).
Brake Torque = Forcebrake×Effective Wheel Radius
Considering the brake force of 1758 N and
effective wheel radius of 10.25 inch, we get,
Brake Torque = 458 Nmm
4.1 Design of Wishbones
We have obtained the length of upper and lower
wishbones from optimized RC Geometry (refer table 1).
Additionally, we have also selected the appropriate
material for wishbones. Shock absorber is mounted on
lower wishbones with motion ratio of 0.8 providing
precise simulation results. Thus, following figure
represents the 3D model of designed lower wishbone.

Fig -4: CAD Model of Lower Wishbone
4.2 Design and Analysis of Knuckle
It is the stationary part of the wheel assembly which has
mountings for suspension links as well as brake caliper.
Suspension links are mounted on knuckle mainly using
ball joint which provides total angle of action about 30°. It
is important to note that, ball joint should not be mounted
at angle greater than 40° which can cause repeating failure
of ball joint due to application instantaneous peak load.
This can lead to severe damage of wheel assembly.
Fig -5: CAD Model of Knuckle
Based on force calculation performed earlier, we will now
discuss the exact location at which forces must be applied
while performing the Static Structural analysis in ANSYS
Workbench. Importantly, fixed support must be applied to
stub axle hole and then other loading conditions are
applicable. Cornering force is applied at ball joint
mounting hole in lateral direction while braking torque is
applied at caliper mounting hole in either anticlockwise or
clockwise direction. Steering force is applicable to steering
arm as discussed earlier and bump force must applied at
lower ball joint mounting hole where initial impact takes
place.
After the applying the discussed loading conditions,
analysis is performed which provided following results.
Fig -6: Stress Analysis of Knuckle
Fig -7: Total Deformation of Knuckle
As it can be seen that, maximum induced stress as well as
total deformation are well within Factor of Safety limit, we
can conclude that design and analysis of the knuckle is
successfully completed.
4.3 Design and Analysis of Hub
It is rotating part of the wheel assembly which has two
petals for wheel mounting and brake disc mounting on the
either side. Hub should be precisely designed as there are
chances of fouling of brake disk petal with mounting bolts.
Additionally, hub failure mainly occurs due torsion, hence
petal thickness should be kept appropriately according to
selected material. Further weight reduction can also be
achieved by providing slots on the wheel mounting petal.
However, stress analysis must be performed for the same.

Fig -8: CAD Model of Hub
Similar to that of knuckle, we will now discuss the exact
location at which forces must be applied while performing
the Static Structural analysis in ANSYS Workbench. It
should noted that, while applying the cornering force in
lateral direction and bump force in vertical direction on
wheel mounting holes, fixed support must be applied to
bearing mounting location. On the other hand, while
applying brake torque on wheel mounting holes in either
clockwise or anticlockwise direction, fixed support must
be applied to brake disk mounting holes.
Following results are obtained after performing the
analysis.
Fig -9: Stress Analysis of Hub
Fig -10: Total Deformation of Hub
From the static structural analysis of wheel hub, it is
observed that total deformation and induced maximum
stress is well within limit. Hence, we can conclude that,
design and analysis of hub is successfully completed.
5. SELECTION OF SHOCK ABSORBERS
Radflo Air Shocks 2.0 are selected, as the stiffness can be
adjusted easily by varying the air pressure. It has total eye
to eye length of 19.5 inches which is used while drawing
the roll centre geometry. As per design, it is mounted on
lower wishbone with the motion ratio of 0.8 at an angle of
54° with respect to vertical axis.
6. CONCLUSION
After designing and simulating the optimized roll centre
geometry using MSC Adams car software, lengths of
important suspension components are obtained. This
further led to material selection and designing of the
components such as wishbones, knuckle, hub, etc using
CATIA V5 software. Furthermore, static structural analysis
of these components is performed using force analysis in
ANSYS Workbench Software. This provided stress and
deformation results within acceptable factor of safety limit
which confirms the successful design and analysis of the
suspension components.
REFERENCES
1. Smith, Caroll. 1978, “Tune to win”, Chapter 2, Aero
publishers Inc.
2. Thomas D. Gillespie, “Fundamentals of Vehicle
Dynamics”, SAE Inc.
3. Trushar Bhope, Prof. Anurag Nema, Prof.
Anantharma, “Design, Analysis and Experimental
Investigation of Double Wishbone Independent
Suspension System for Agriculture Trolley”,
International Research Journal of Engineering and
Technology (IRJET)’ e-ISSN: 2395-0056, Volume
3, Issue 9, Sep-2016, pp.1067-1071.

4. Asst. Prof. N.Vivekanandan, Abhilash Gunaki,
Chinmaya Acharya, Savio Gilbert and Rushikesh
Bodake, “Design, Analysis And Simulation of
Double Wishbone Suspension System”,
“International Journal of Mechanical Engineering
(IIJME)”, Volume 2, Issue 6, June 2014,pp.1-7.
5. Reena Mishra, Anand Baghel, “Design, Analysis
and Optimization of front suspension wishbone of
BAJA 2016 of All-terrain vehicle- A Review”,
International Journal of Research in Mechanical,
Mechatronics and Automobile Engineering
(IJRMMAE), ISSN : 2454-1435, Volume 2, Issue 3,
28th Feb, 2017, pp.40-52.

IRJET - Design, Simulation and Analysis of Double Wishbone Suspension System for an All-Terrain Vehicle (ATV)

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