Yogesh Sharma et al. 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098
ISSN (Print): 2395-4752
International Journal of Science,
Engineering and Technology
An Open Access Journal
Comparison of Performance of Multi Leaf Springs
of Automobile after Changing Its Cross Section
1
Yogesh Sharma, 2Dr. V.N. Bartaria
Abstract
Automotive Industry is now a day is emerging with new implementations and techniques through
the extraordinary ordinary researches that have resulted in existence of new materials and various
optimized techniques. In this research paper Multi leaf soaring is chosen for the optimization
process as the improvement in the multi leaf spring can result in betterment of existing multi leaf
spring user vehicles. In vehicles Multi Leaf Springs accounts 10 % - 20 % of the unspring Weight and
also an important suspension device used to provide passengers the comfort and safety while
driving. Leaf Spring is used in various categories of Vehicles such as Light Commercial Vehicles and
heavy duty Commercial Vehicles as a suspension System to resist jerks due to ups and downs while
driving. Among different types of springs commonly used in automotive industry Multi leaf spring is
one of the common types. These consist of narrow plates of different types and sizes. These leaf
springs are usually thick in middle and tapered outward at the end. Various Leaf spring users use
these multiple leaf springs to tow heavier loads at the end of their vehicles. Multi Leaf Spring
consists of various leaf of varying lengths in line at the top of each other. The shorter the leaf spring
closer to the bottom it will be giving it the same semielliptical shape a single leaf spring gets from
being thicker in the middle.
For this research work the design dimensions of the existing convention leaf spring are taken and
Results are observed after changing the cross Section of the Leaf Spring without changing its
existing material properties to provide better and Optimized results for which Catia V5 R20 software
is used for modeling and analysis is performed using ANSYS 14.5.
Keywords: - Computer aided engineering (CAE), Finite element analysis, Cross Section, Multi leaf
spring.
Introduction
In this research paper the research work is carried
out on changing the cross section of Leaf Spring by
giving it an arc shape at the bottom in cross section.
The introduction of New Design parameters can
make the possible improvements in the efficiency
and performance of leaf spring without any
reduction in load carrying capacity and stiffness.
Performance vehicles are more likely preferred by the
today’s generation.
Leaf spring absorbs vertical vibrations and impacts
due to load irregularities by means of variation in the
spring deflection show that potential energy is
stored in spring as strain energy and then release
slowly so, increasing energy stored capability of a
leaf spring insures a better suspension system.
Also the change in parameters with increasing
strength of products is becoming more important for
the researchers and automotive experts to sustain in
1
the
prevailing
circumstances
where
high
The large vehicle needs a good suspension system
that can deliver a good ride and handling to the
drivers while driving. At the same time that
component needs to have high fatigue life to resist
more jerks while running.
Most of researches focused on improving fatigue
resistance by shoot penning process, making the
1
Corresponding Author’s Email: [email protected]
© 2015 Yogesh Sharma et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License
(http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the
original
work is properly credited.
121
Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
nucleation and propagation of fatigue cracks
difficult. Few publication, which are listed in
references attempted to changes the materials or
design values of leaf spring to increase its efficiency
or performance.
Figure 1: Multi Leaf Spring
Design variables of multi leaf spring
Following dimensions are taken for Existing Leaf
Spring as well as Modified leaf springs.
TOOL (Modeling & Analysis)
Modeling in CAD software’s is dedicated for the
specialized Works of 3D-modeling. The model of the
multi leaf spring structures also includes many
complicated parts. Modeling of multi leaf spring is
done in CATIA V5 R20.All the Nine leafs are first
modelled in part Design Work bench and then
Assembled in Assembly workbench of CATIA V5
R20.The assembled .Product file is then converted to
.Stp for importing and analysis is performed in Ansys
14.5.
The main Emphasis is given on the cross section of
Leaf Spring to get better and optimized results and
improved life of leaf spring. In this three Variant of
leaf springs are leaf springs of Cross Section with
Radius 135, Radius 200, and Radius 400 Respectively
Table 1: Dimensions of leaf spring
Parameter Name
Value
Span length(eye to eye)
1450 mm
Number
leaves
length
2
graduated
7
of
full
Number of
length leaves
Width of leaves
70 mm each
Thickness of leaves
12 mm each
Length of full
leaves(L1 and L2)
length
Length
of
graduated
leaves (L3, L4, L5, L6, L7,
L8, L9)
1450 mm
1320, 1140, 940, 800,
640, 464, 244 mm
Figure 3: Cross-section of Existing Multi Leaf Spring
Figure 2: Leaf Arrangements in Multi Leaf Spring
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Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
Material properties
There are Four leaf springs on which the analyses are
going to perform, one is conventional steel leaf
spring and other three are modified leaf springs. The
properties of the conventional steel material Sup9
being used in this analysis are shown in Table-1.
Figure 4: Cross Section with Radius 135
Figure 5: Cross Section with Radius 200
Figure 6: Cross Section with Radius 400
ANSYS (Analysis Tool)
ANSYS is Computer Aided engineering analysis
software used for solving general analysis purpose
like finite element Analysis for finding the
approximate numerical solutions of mechanical
problems. Here ANSYS 14.5 is used for analyzing the
performance of conventional and Modified leaf
spring. Leaf spring is modeled in Catia V5 R20
software and it is imported in ANSYS 14.5. The
conventional spring steel leaf spring and the
modified leaf springs were analyzed under similar
conditions using ANSYS software.
In this section the conventional steel and Modified
Multi Leaf Spring leaf spring will be analyzed to see
the various results from the static Structural analyses.
The software used to perform the analysis is
ANSYS® 14.5. ANSYS software is used to analyze the
stresses by performing static analysis for the given
leaf spring specification and to determine the
stiffness in leaf springs.
Selection of Material
Table 2: Material Properties of existing SUP9
(55Si2Mn90)
PARAMETER
VALUE
Material selected
SUP9
Young’s Modulus (E)
210000 Mpa
Poisson’s Ratio
0.26
Tensile Strength Ultimate
1272 MPa
Tensile Strength Yield
1158 MPa
Density
0.785
Behavior
Isotropic
Shows the mechanical properties of (Sup9) material,
which can be taken as per Ansys Standard material
library
Methodology, Boundary and loading Conditions
1.
2.
3.
4.
5.
6.
7.
8.
Computer model generation.
Assigning material properties to all the nine
leaves.
Applying boundary conditions.
Applying load 35000N.
Assigning interaction property between the
leaves.
Mesh generation.
Solving for obtaining results
Creating the job to get output data file
The leaf spring is placed on the axle of the vehicle;
the frame of the vehicle is attached to the ends (by
eyes) of the leaf spring. The ends of the leaf spring
are made in the form of an eye. The front eye of the
leaf spring is attached straightly with a pin to the
frame so that the eye can revolve without restraint
about the pin but no translation is takes place. The
back eye of the spring is linked to the shackle which
is a flexible link the next end of the shackle is linked
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Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
to the frame of the vehicle. One eye of the leaf
spring is reserved fixed (cylindrical support) and the
other eye is given certain degree of rotation to allow
the leaf spring to deflect by some amount along its
length to meet the actual conditions for both the leaf
spring (steel and composite) which is shown in Fig.
below. After this load is applied of magnitude 36000
N in the upward direction at the center of the Leaf
Spring. This specific computation of load to be
applied has been completed on the basis of Gross
Vehicle Weight (GVW).
Figure 10: Max. Von- Mises Stress on Conventional
Leaf Spring
After Solving Procedure Results of Maximum VonMises Stress (Equivalent Stress) on Conventional
Multi leaf spring with 882 Mpa as Maximum Value
and 0.091 Mpa as Minimum Value.
Deformation in Modified Multi Leaf Spring (400
Radius)
Figure 7: Meshing of Multi leaf spring
Figure 8: Force and boundary conditions on Multi
leaf spring
Deformation in conventional Multi Leaf Spring
Figure 11: Total Deformation in Modified Multi Leaf
Spring (400 Radius)
After Solving Procedure Results of Deformation/
Deflection on Conventional Multi leaf Spring with
118.99 mm as Maximum Value and 10.26 mm as
Minimum Value.
Stress in Modified Multi Leaf Spring (400 Radius)
Figure 9: Total deformation on Conventional Leaf
Spring
After Solving Procedure Results of Deformation/
Deflection on Conventional Multi leaf Spring with
145.53 mm as Maximum Value and 1.19 mm as
Minimum Value.
Figure 12: Max.Von-Mises Stress in Modified Multi
Leaf Spring (400 Radius)
Stress in conventional Multi Leaf Spring
124
Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
After Solving Procedure Results of Maximum VonMises Stress (Equivalent Stress) on Conventional
Multi leaf spring with 754.64 Mpa as Maximum Value
and 0.095 Mpa as Minimum Value.
Deformation in Modified Multi Leaf Spring (200
Radius)
Figure 15: Total Deformation in Modified Multi Leaf
Spring (135 Radius)
After Solving Procedure Results of Deformation/
Deflection on Conventional Multi leaf Spring with
67.77 mm as Maximum Value and 5.98 mm as
Minimum Value.
Figure 13: Total Deformation in Modified Multi Leaf
Spring (200 Radius)
Stress in Modified Multi Leaf Spring (135 Radius)
After Solving Procedure Results of Deformation/
Deflection on Conventional Multi leaf Spring with
92.914 mm as Maximum Value and 8.382 mm as
Minimum Value.
Stress in Modified Multi Leaf Spring (200 Radius)
Figure 16: Total Stress in Modified Multi Leaf Spring
(135 Radius)
After Solving Procedure Results of Maximum VonMises Stress (Equivalent Stress) on Conventional
Multi leaf spring with 596.85 Mpa as Maximum Value
and 0.097 Mpa as Minimum Value.
Figure 14: Total Stress in Modified Multi Leaf Spring
(200 Radius)
After Solving Procedure Results of Maximum VonMises Stress (Equivalent Stress) on Conventional
Multi leaf spring with 679.09 Mpa as Maximum Value
and 0.063 Mpa as Minimum Value.
Deformation in Modified Multi Leaf Spring (135
Radius)
On solving all the four Multi Leaf springs Assemblies
for Total Deformation and Max. Equivalent stress
(Von-Mises Stress) it is been observed that on
changing the radius Of cross sections there is
improvement in the deformation and stress
generation in Multi leaf spring. As it will increase the
spring height and gap between the different leafs of
Multi leaf spring ultimately giving the better
performance and ride quality.
Results and Discussion
As presented above, we discussed the modeling and
analyses of the conventional steel and three
composite leaf springs with the same loading and
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Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
boundary conditions. The results of the analyses are
shown through images. The results are tabulated in
the Table Below.
Table: Comparison between steel and three Modified
leaf springs
Parameter
Conventional
Multi
Leaf
Spring
Modified
leaf
Spring
400R
Modified
leaf
Spring
200R
Modified
leaf
Spring
135R
Von-Mises
Stress
(MPa)
882
754
679
596
Total
Maximum
Deflection
(mm)
157
118
92
67
leaf spring and modified leaf spring are found with
the great difference. Deflection of Modified leaf
spring is less as compared to conventional leaf
spring with the same loading condition. Modified
Leaf spring shows failure. At maximum load
condition also Modified Leaf Spring shows the
minimum stresses as compared to conventional Leaf
Spring. Therefore Modified leaf spring can be used
on smooth roads with high performance
expectations.
Scope of Work
After this research Work other researches can also be
carried out on the same designs of Multi leaf Spring.
Such As:
1. Other FEA methods can be used to calculate other
design parameters.
Table: Comparison of Conventional and three
modified leaf springs on basis of (a) Vonmises stress
(b) Total maximum deformation
2. Some different types of cross sections can also be
used in place of flat cross sections.
3. Other engineering techniques can also be used to
get more optimized results on Multi leaf Spring.
4. Implementation of new materials on the same
design can also give more precise and better results.
References
[1]. Ram Krishna Rathore and Edward Nikhil Karlus, Weight
Optimization of Mono Parabolic Leaf Spring International
Journal of Engineering Research & Technology (IJERT)
IJERTIJERT ISSN: 2278-0181Vol. 3 Issue 7, July - 2014.
Graph 1: Vonmises stress
[2]. Damping System For Added Comfort And Longer Life”
Ijret: International Journal of Research in Engineering and
Technology eISSN: 2319-1163 | pISSN: 2321-7308
[3]. Jitender Kumar Singh Jadon, Sanjeev Kumar “Static
Analysis and Modification of Multi – Leaf Spring Using
Catia V5 International Journal of Engineering Research &
Technology (IJERT), ISSN: 2278-0181 IJERTV3IS051195 Vol.
3 Issue 5, May - 2014
Graph 2: Total deformation/Deflection
Conclusion
As seen above under the same static load conditions
deflection and stresses in theoretical values of steel
[4]. Prof.Vidyadhar .C. Kale, Ashish Goel, Dabhade Roshan
Megharaj “Design of Leaf Spring for Light Commercial
Vehicle for Enhanced Mechanical Properties and Reduce
Weight to Improve the Performance Over a Life
International Journal of Engineering Sciences & Research
Technology , November, 2014
[5]. Manas Patnaik, Narendra Yadav, Ritesh Dewangan
“Study of a Parabolic Leaf Spring by Finite Element Method
& Design of Experiments” International Journal of Modern
Engineering Research Vol.2, Issue 4, July-Aug 2012 pp-
126
Yogesh Sharma et al. International Journal of Science, Engineering and Technology, 2015, Volume 3 Issue 6
ISSN (Online): 2348-4098 , ISSN (Print): 2395-4752
1920-1922.
[6]. Prof Prahalad Sawant Badkar “Design Improvements
of Leaf Spring of BEML Tatra 815 VVNC 8 X 8 Truck”
International Journal of Emerging Technology and
Advanced Engineering (ISSN 2250-2459, Volume 3, Issue 1,
January 2013)
[7]. Edward Nikhil Karlus, Rakesh L. Himte, Ram Krishna
Rathore “Optimization of Mono Parabolic Leaf Spring”
International Journal of Advances in Engineering &
Technology, Mar. 2014.
Author’s details
1
M.Tech. Scholar, Industrial Design, LNCT College, Bhopal,
INDIA, Email: [email protected]
2
Head of Department, Mechanical Engineering, LNCT
College, Bhopal, INDIA
Copy for Cite this Article- Yogesh Sharma and Dr. V.N.
Bartaria, ‘Comparison Of Performance Of Multi Leaf Springs
Of Automobile After Changing Its Cross Section’,
International Journal of Science, Engineering and Technology,
Volume 3 Issue 6: 2015, pp. 121- 127.
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