Design analysis of the roll cage for all terrain

IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 333
DESIGN ANALYSIS OF THE ROLL CAGE FOR ALL - TERRAIN
VEHICLE
Sandeep Garg1
, Ravi Shankar Raman2
1, 2
Department of Mechanical Engineering, ABES Engineering College, Ghaziabad
sandeep.garg@abes.ac.in, ravi.raman21@gmail.com
Abstract
We have tried to design an all terrain vehicle that meets international standards and is also cost effective at the same time. We have
focused on every point of roll cage to improve the performance of vehicle without failure of roll cage. We began the task of designing
by conducting extensive research of ATV roll cage through finite element analysis. A roll cage is a skeleton of an ATV. The roll cage
not only forms the structural base but also a 3-D shell surrounding the occupant which protects the occupant in case of impact and
roll over incidents. The roll cage also adds to the aesthetics of a vehicle. The design and development comprises of material selection,
chassis and frame design, cross section determination, determining strength requirements of roll cage, stress analysis and simulations
to test the ATV against failure.
Keywords: Roll cage, material, finite element analysis, strength
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I. INTRODUCTION
The objective of the study is to design and develop the roll
cage for All - Terrain Vehicle. Material for the roll cage is
selected based on strength, cost and availability. The roll cage
is designed to incorporate all the automotive sub-systems. A
software model is prepared in Solid works software. Later the
design is tested against all modes of failure by conducting
various simulations and stress analysis with the aid of Ansys
Software. Based on the result obtained from these tests the
design is modified accordingly. After successfully designing
the roll cage, it is ready for fabricated.
The vehicle is required to have a combination frame and roll
cage consisting of steel members. As weight is critical in a
vehicle powered by a small engine, a balance must be found
between the strength and weight of the design. To best
optimize this balance the use of solid modeling and finite
element analysis (FEA) software is extremely useful in
addition to conventional analysis. The following paper
outlines the design and analysis of the roll cage design
2. DESIGN & DEVELOPMENT
The design and development process of the roll cage involves
various factors; namely material selection, frame design,
cross-section determination and finite element analysis. One
of the key design decision of our frame that greatly increases
the safety, reliability and performance in any automobile
design is material selection. To ensure that the optimal
material is chosen, extensive research was carried out and
compared with materials from multiple categories. The key
categories for comparison were strength, weight, and cost. The
details of each step are given below.
2.1 Material Selection
While the rules set many factors of the material’s geometry,
there are many other limitations. These limitations include the
method of fabrication and industry standards for the material.
The frame will be built using a bent tube construction and
MIG welded joints. MIG welding becomes difficult at wall
thicknesses less than 0.035 inches. The tubing bender that will
be used for the fabrication can bend a maximum of 1.5 inch
diameter tube with a 0.120 inch wall thickness. It also requires
that the tube have a minimum wall thickness of 0.055 inches.
The geometry is also limited by industry standards. It is
important to utilize commonly available tubing sizes and
materials. Tubing is available in standard fractional sizes to
the 1/8th of an inch: 1, 1.125, 1.25, 1.375, and 1.5. The wall
thickness is limited to: 0.035, 0.049, 0.058, 0.065, and 0.083
inches. The most commonly available material for this type of
tubing is “ASTM 106 grade B Steel”.
The ASTM 106 grade B Steel has the same Modulus of
Elasticity (E) and density as the mild steel, so using it does not
affect the weight or stiffness in members with the same
geometry.
After a careful study, based on the properties and cost and
availability criteria, it was found that the following material
with its properties given should be used.

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Density (x 1000 kg/m3) 7.7-8.03
Poisson‟s ratio 0.27-0.30
Elastic Modulus (GPa) 190-210
Tensile Strength (MPa) 415
Yield Strength(MPa) 240
Elongation (%) 20
Reduction in Area (%) 48
Hardness (HRB) 100
Analysis was carried out on solid works Interface for these
sections under three conditions:
Compression test
Tension test
Bending test as simply supported
The pipe of 1” O.D and .12” thickness was selected for
designing based on analysis result.
Report of Compression Test
Fig-1 Compression test for tube sample
Fig2 Compression von-mises stress for selected pipe
Report of Tension Test
Fig-3 Tensile von-mises stress for selected pipe
Report of Pipe Bending
Fig-4 bending translational displacement for selected pipe
2.2 Frame Design
To begin the initial design of the frame, some design
guidelines were required to be set. They included intended
transmission, steering and suspension systems and their
placement, mounting of seat, design features and
manufacturing methods. It is also required to keep a minimum

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clearance of 3 inches between the driver and the roll cage
members. It is also necessary to keep weight of the roll cage as
low as possible to achieve better acceleration. It is necessary
to keep the center of gravity of the vehicle as low as possible
to avoid toppling. Mounting heavier components such as
engine, driver seat etc. directly on the chassis is one way of
achieving low center of gravity. Also it is imperative to
maintain the integrity of the structure. This is done by
providing bends instead of welds which in turn reduces the
cost. A layout of the chassis within the given geometrical
constraints is as shown in Fig.5
Fig-4 Solid modeling of ATV Roll Cage
3. FINITE ELEMENT ANALYSIS
After finalizing the frame along with its material and cross
section, it is very essential to test the rigidity and strength of
the frame under severe conditions. The frame should be able
to withstand the impact, torsion, roll over conditions and
provide utmost safety to the driver without undergoing much
deformation. Following tests were performed on the roll cage.
Front impact
Side impact
Rear impact
3.1 Front Impact Test
Front Impact Test was carried out assuming a vehicles having
300 kg mass and travelling with velocity of 60km/h colliding
head on with a stationary wall. The impact force was
calculated using the kinetic energy transfer theory.
Impact energy = (1/4) x M x (velocity)2
Work done= force x displacement
Front Impact Test
Loading= 7500 N on front corner
Boundary Conditions:
1. Symmetry (Plane normal to Z-axis)
2. All DOF are fixed at rear corner points.
Fig. 5: Vonmises Stress plot
Fig. 7: Displacement plot

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Fig 8: Deformation plot
Results:
Maximum VonMises Stress= 56 MPa
Incorporated Factor of Safety= σyt/σmax
= 386/56
= 6.89
As factor of Safety for automobiles goes up to 8, hence design
is safe against specified stress.
3.2 Rear Impact Test
Loading= 6850 N on rear corner
1. Symmetry (Plane normal to Z-axis)
2. All DOF are fixed at front corner points.
Fig. 9: Boundary conditions
Fig. 10: Vonmises stress plot

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Results:
Maximum Von Mises Stress= 74 MPa
= 386/74
= 5.21
Hence design is safe against specified stress.
3.3 Side Impact Test
Loading= 6500 N on left side impact member.
1. Symmetry (Plane normal to Z-axis and along Y-axis)
2. All DOF on SIM are fixed.
Fig. 13: Boundary condition
Fig. 14: Vonmises stress plot
Fig. 16: Deformation plot
Results:
Maximum VonMises Stress= 77 MPa
= 386/77
= 5.01
Hence design is safe against specified stress.
CONCLUSIONS
The FEA analysis demonstrated the structural superiority
while maintaining a lower weight to strength ratio. The
customers' needs were given the topmost priority as they are
our ultimate goal. The vehicle demonstrated satisfactory
dynamic stability while maneuvering rough terrains. The
design of the vehicle is kept very simple keeping in view its

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manufacturability. Thus at this point of time our vehicle
design can be predicted to heading in correct direction. There
is a lot of future work which is essentially required to fine tune
the performance. The design, development and fabrication of
the roll cage is carried out successfully. The roll cage is used
to build an ATV by integrating all the other automotive
systems like transmission, suspension, steering, brakes and
other miscellaneous elements.
REFERENCES
[1] Khelan Chaudhari, Amogh Joshi & Ranjit Kunte,
Design And Development Of Roll Cage For An All-
terrain Vehicle, International Journal on Theoretical
and Applied Research in Mechanical Engineering
(IJTARME), ISSN : 2319 – 3182, Volume-2, Issue-4,
2013.
[2] S.Kalaivanan & D.Manikandan, Complete Design and
Finite Element Analysis of an all Terrain Vehicle,
International Journal of Mechanical and Industrial
Engineering (IJMIE), ISSN No. 2231 –6477, Volume-
1, Issue-3, 2012.
[3] William B. Riley and Albert R. George, “Design,
Analysis and Testing of a Formula SAE Car Chassis”,
SAE TECHNICAL PAPER SERIES 2002-01-3300
[4] Herb Adams, “Chassis Engineering”, Berkley
Publishing Group New York
[5] F. L. Singer , “Strength of Materials”, Harper and Row
Publishers, New York.

Design analysis of the roll cage for all terrain

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Design analysis of the roll cage for all terrain