Leaf springs are used in vehicles for suspension purpose in all type of vehicles. Ample amount of work has been done on the analysis of leaf spring. Researcher focused on theÂ  analysis of stresses developed in spring by using different FEM tool also several worked on predict fatigue life of leaf spring. After review of available literature on leaf spring it is found that the very few literature is available on analysis of springs used for light commercial vehicle. This paper describes the static analysis of multi leaf spring by using experimental method i.e. strain gauge under various loading conditio

Gaur, Prof. A. V.

Kale, Mr. S. S.

English

International Research Journal of Multidisciplinary Studies (IRJMS)

INTERNATIONAL RESEARCH JOURNAL OF MULTIDISCIPLINARY STUDIES 
& SPPP's, Karmayogi Engineering College, Pandharpur Organize  National 
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Stress Analysis of Multi Leaf Spring by Using Experimental Method 
 
Mr. S. S. Kale1 Prof. A.V. Gaur2 
1 P.G. Student 2 Assistant Professor 
Brahmadevdada Mane Institute of Technology, Solapur, Maharashtra 
Abstract – Leaf springs are used in vehicles for suspension purpose in all type of vehicles. Ample amount of 
work has been done on the analysis of leaf spring. Researcher focused on the  analysis of stresses developed in 
spring by using different FEM tool also several worked on predict fatigue life of leaf spring. After review of 
available literature on leaf spring it is found that the very few literature is available on analysis of springs used 
for light commercial vehicle. This paper describes the static analysis of multi leaf spring by using experimental 
method i.e. strain gauge under various loading condition. 
Key words: Leaf spring, FEM, Fatigue failure. 
 
I. INTRODUCTION  
A leaf spring is a simple form of spring commonly 
used for the suspension in wheeled vehicles. 
Originally called a laminated or carriage spring, and 
sometimes referred to as a semi-
elliptical spring or cart spring, it is one of the oldest 
forms of springing, dating back  to medieval times 
A leaf spring takes the form of a slender arc-shaped 
length of spring steel of rectangular cross-section. 
In the most common configuration, the center of the 
arc provides location for the axle, while tie 
holes are provided at either end for attaching to the 
vehicle body. For very heavy vehicles, a leaf spring 
can be made from several leaves stacked on top of 
each other in several layers, often with 
progressively shorter leaves. Leaf springs can serve 
locating and to some extent damping as well as 
springing functions. While the interleaf friction 
provides a damping action, it is not well controlled 
and results in stiction in the motion of the 
suspension. For this reason some manufacturers 
have used mono-leaf springs. 
 
Figure 1-Laminated semi-elliptic spring 
 
II. HISTORY  
Leaf spring was very common on automobiles, right 
up to the 1970s in Europe and Japan and late 70's in 
America when the move to front wheel drive, and 
more sophisticated suspension designs saw 
automobile manufacturers use coil springs instead. 
Today leaf springs are still used in heavy 
commercial vehicles such as  
vans and trucks, SUVs, and railway carriages. For 
heavy vehicles, they have the advantage of spreading 
the load more widely over the vehicle's chassis, 
whereas coil springs transfer it to a single point. 
Unlike coil springs, 
leaf springs also locate the rear axle, eliminating the 
need for trailing arms and a Panhard rod, thereby 
saving cost and weight in a simple live axle rear 
suspension. 
 
III. REVIEW OF LITERATURE  
  
J.J. Fuentes a, H.J. Aguilar, J.A. Rodrıguez, E.J. and 
Herrera worked on ‘premature fracture in automobile 
leaf springs’ in 2009. In this work, the origin of 
premature fracture in leaf springs, used in 
Venezuelan buses, is studied. To this end, common 
failure analysis procedures, including examining the 
leaf spring history, visual inspection of fractured 
specimens, characterization of various properties and 
simulation tests on real components, were used. It is 
concluded that fracture occurred by a mechanism of 
mechanical fatigue, initiated at the region of the 
central hole, which suffered the highest tensile stress 
levels. Several factors (poor design, low quality 
material and defected fabrication) have combined to 
facilitate failure. Preventive measures to lengthen the 
service life of leaf springs are suggested. 
G Harinath Gowd and E Venugopal Goud has 
presented Static Analysis of Leaf Spring in 2012 In 
Their work, leaf spring is modeled and static analysis 
is carried out by using ANSYS software and it is 
concluded that for the given specifications of the leaf 
spring, the maximum safe load is 7700N. It is 
INTERNATIONAL RESEARCH JOURNAL OF MULTIDISCIPLINARY STUDIES 
& SPPP's, Karmayogi Engineering College, Pandharpur Organize  National 
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observed that the maximum stress is developed at 
the inner side of the eye sections, so auther 
suggested that in eye design and fabrication and 
material selection. The selected material must have 
good ductility, resilience and toughness to avoid 
sudden fracture for providing safety and comfort to 
the occupants. 
Mr. V. K. Aher , Mr. P. M. Sonawane 
Static And Fatigue Analysis of Multi Leaf Spring 
Used In The Suspension System Of LCV (2012) 
The fatigue life prediction is performed based on 
finite element analysis and fatigue life simulation 
method. FEM gives the prediction of critical area 
from the viewpoint of static loading. The results of 
non- linear static analysis of 2D model of the leaf 
spring using the commercial solver and analytical 
results shows better correlation. The stiffness of the 
leaf spring is studied by plotting load versus 
deflection curve for whole working load range 
which shows the linear relationship. Using the 
constant amplitude loading, the fatigue damage and 
life of the spring has been predicted. From the 
damage contour, the highest 
damage value is in acceptable range. This study will 
help to understand more the behavior of  
the spring and give information for the 
manufacturer to improve the fatigue life of the 
spring using CAE tools. 
It can help to reduce cost and times in research and 
development of new product. 
Santosh Krishnaji Sinde e tal Static, Modal and 
Fatigue Life Prediction through CAE for a Leaf 
Spring used in Light Commercial Vehicle (2014) 
Above work describes static, modal and fatigue 
analysis of a existing leaf spring and modifying 
existing   steel leaf spring by reducing no of 
graduated leaves and increasing thickness. The 
dimensions of a modified leaf spring of a LCV are 
taken and are verified by design calculations. .  At 
5kN load the deflection value and bending stress 
value for existing leaf spring from simulation are 
102.43mm and 543.03N/mm2 respectively. .At 
10kN load the deflection value and bending stress 
value for existing leaf spring from simulation 
are204.85mm and 1086.06N/mm2 respectively. At 
5kN load the deflection value and bending stress 
value for modified leaf spring from simulation are 
71.61mm and 523.70N/mm2 respectively. At 10kN 
load the deflection value and bending stress value 
for modified leaf spring from simulation are 
143.23mm and 1047.35N/mm2 respectively. 
All analytically calculated values of deflection and 
stresses are closely matching with values obtained 
from 
non-linear static stress analysis. From modal analysis 
it was found that the fundamental bending mode 
frequency of existing leaf spring is 8.80Hz and for 
modified leaf spring 10.68Hz. From fatigue 
simulation the minimum life of existing leaf spring 
was 3.94×105 cycles and for modified leaf spring 
1.47×107 cycles. 
Sarika S Yede and M.J Shaikh worked on  Modeling 
and Finite Element Analysis of Leaf Spring in their 
work involves design and analysis of a conventional 
leaf spring under static and dynamic loading 
conditions. The 3D model is prepared in Creo 1.0, 
and then analysis is performed in the ANSYS 11.0 
by considering same load in static and dynamic 
loading. For the cost reduction in existing leaf spring 
modification carried out by iteration method 
considering three cases such as varying number of 
leaves, varying width and varying thickness. The 
optimization has been carried out to satisfy the 
permissible value of factor of safety. The results are 
verified by comparison of Analytical and Finite 
Element Method. All analytically calculated values 
of deflection and stresses are closely matching with 
values obtained from ANSYS software. From the 
preliminary study it is concluded that from the 
comparison of materials Eglass /epoxy material is 
better than composite material & EN-45 Steel. And 
in comparison of shapes parabolic spring is better 
than conventional & elliptical leaf spring. Their 
project is in progress. Further it is decided to develop 
the CAD model of Leaf Spring. and to carry out 
Modeling by using Pro-E & analysis is carried out by 
using ANSYS Software by applying boundary 
conditions, & considering Stresses acting on leaf 
Spring & meshing on each component. 
V.K.Aher,R.A.Gujar,J.P.Wagh&P.M.Sonawane 
presented  Fatigue Life Prediction of Multi Leaf 
Spring used in the Suspension System of Light 
Commercial Vehicle (2012) 
This work describes static and fatigue analysis of a 
steel leaf spring of a light commercial vehicle 
(LCV).  
The dimensions of the leaf spring of a LCV are taken 
and are verified by design calculations. The non-
linear 
 static analysis of 2D model of the leaf spring is 
performed using NASTRAN solver and compared 
with analytical results.      
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The preprocessing of the model is done by using 
HYPERMESH software. The stiffness of the leaf 
spring  
is studied by plotting load versus deflection curve 
for various load applications. The simulation results 
are compared with analytical results. The fatigue 
life of the leaf spring is predicted using MSC 
Fatigue software. 
Y.S. Kong , M.Z. Omar, L.B. Chua,S. Abdullah 
presented paper on Fatigue life prediction of 
parabolic leaf spring under various road conditions 
(2014) This paper serves to simulate the fatigue life 
of a parabolic leaf spring designunder variable 
amplitude loading (VAL). VALs carry the road 
signal that provokes fatigue failure on leaf spring. 
In order to seek for comprehensive leaf spring 
fatigue assessment, VALs signal were gathered 
through measurements from various road conditions 
such as highway, curve mountain road and rough 
rural area road. Subsequently, fatigue life of 
particular leaf spring design was predicted using 
finite element (FE) stress–strain model together 
with VALs signal as load input. For more 
conservative way, Morrow and Smith Watson 
Topper (SWT) mean stress correction methods were 
also applied. The results indicate that fatigue life of 
leaf spring is lowest during rough road mission, 
followed by curve mountain road and smooth 
highway road respectively. Additional design 
modification to prolong the fatigue life of the 
parabolic leaf spring is compulsory. The road VALs 
has provided even more realistic fatigue life 
estimation of parabolic leaf spring design when 
compared to traditional controlled laboratory 
method. Fatigue life predictions of parabolic leaf 
spring on smooth highway, curve mountain road 
and rough rural area road were presented. FE model 
together with VAL was used as the input to the 
fatigue life and damage simulation. FE method has 
provided the critical region of the parabolic leaf 
spring where the strain gauge was attached. Strain 
signal represents the parabolic leaf spring loading 
history when the bus travels on the particular road. 
Through this analysis, prediction of actual leaf 
spring life based on various road conditions was 
obtained where it could never be predicted in lab 
condition. 
 
Figure 2.  Parabolic leaf spring boundary conditions. 
Based on the simulation result, rural area rough road 
condition contributed highest damage to the 
parabolic leaf spring followed by curve mountain 
road and smooth highway road. Therefore, life of 
parabolic spring during rough road operations is 
lowest, and the second is mountain road condition. 
Smooth highway consists of highest life compared to 
others. Parabolic leaf spring redesign is required to 
be reconsidered when the bus is used for curve and 
rough roads. During the fatigue simulation, both 
Morrow and SWT model was adopted to estimate 
the fatigue life in more conservative way.  
With the simulation results, description of fatigue 
behavior under various road terrains is possible and 
when bus usage in particular environment is known, 
the duration for parabolic leaf spring to fail in fatigue 
could be estimated. 
 
Figure 3.  Illustration of leaf spring 
experimental vertical stiffness   test setup. 
 
Basaran Ozmena,Berkuk Altiokb, Alper Guzelb, 
Ibrahim Kocyigitb, Serter Atamera 
INTERNATIONAL RESEARCH JOURNAL OF MULTIDISCIPLINARY STUDIES 
& SPPP's, Karmayogi Engineering College, Pandharpur Organize  National 
Conference Special Issue March 2016 
 
Vol. 2, Special Issue 1, March, 2016   ISSN (Online): 2454-8499     Impact Factor: 1.3599(GIF), 
                                                                                                                                      0.679(IIFS) 
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A novel methodology with testing and simulation 
for the durability of leaf springs based on measured 
load collectives (2015) In this study, the aim is to 
present the newly developed testing and simulation 
method for the durability of leaf springs in order to 
direct designers  
in the product development phase. The load spectra, 
which contain the variable amplitude loading to 
determine the fatigue life, were measured from  
different vehicles on rough road testing track. 
Afterwards, accelerated spectra  were generated for 
testing and used in newly built fatigue test bench. 
Also, Finite Element Method (FEM) and Multi 
Body Simulation (MBS) calculations were 
performed and load spectra were processed with 
multichannel fatigue life calculation to generate a 
virtual test rig. This study illustrates a complete 
development process with the cooperation of testing 
and simulation departments to build a durability 
assessment method of leaf springs based on 
accelerated fatigue life testing using variable 
amplitude loading. The following statements can be 
concluded from this project: 
 Forces, displacements and strains on various leaf 
springs were measured from different vehicles on 
the rough 
road track in order to obtain the load spectra for the 
development of testing method. This load collective 
contains the variable amplitude loading which 
determines the fatigue life of the structure.  
Measured load spectra were processed by analyzing 
all of the collected signals in the time and frequency 
domain. Herewith, the total aimed damage and the 
percentage of each track in the aimed damage were 
evaluated. Then, the test signals, which can give the 
aimed damage within the accelerated time, were 
generated. These test signals were used in the newly 
built test bench and damages in this test bench were 
validated with strain measurements on the leaf 
springs. At the end, these determination of test 
signals were repeated for other 
leaf springs to complete the testing method for the 
all types. 
IV. EXPERIMENTAL 
RESULTS  
Table No.I Specification of leaf spring 
1 Material Alloy steel 
2 Young’s Modulus of the spring(MPa) 207000 
3 Ultimate Tensile Strength (MPa) 1584 
4 Total Length of the spring (Eye to Eye) (mm) 1340 
5 Distance between U bolts  (mm) 80 
6 Free Camber (At no load condition) (mm) 96 
7 No. of full length leaves 02 
8 No. of graduated leaves  06 
9 Thickness of leaf (mm) 7 
10 Width of leaf spring (mm) 60 
11 Design Load on each leaf spring (N) 5000 
12 Maximum Load (N) 10000 
 
Table No.II Result of static analysis of leaf spring 
Sr.
No. 
Central 
load (2w) 
in N 
Stress at load 
w (N/mm2) 
Deflection at 
load w (mm) 
1 1000 43.0 20 
2 2000 120.4 40 
3 3000 270.2 60 
4 4000 325.2 81 
5 5000 390.4 102 
6 6000 492.0 123 
7 7000 595.3 144 
8 8000 681.6 163 
9 9000 775.8 184 
10 10000 852.6 205 
 
V  CONCLUSION 
Static analysis of multi leaf spring is carried out by 
experimental method under different loads. There is 
scope to analyze the stresses by using FEM as well 
as experimental method and suggest modification in 
existing leaf spring to reduce stress developed in leaf 
spring. 
                             
REFERENCES 
[1] J.J. Fuentes, H.J. Aguilar, J.A. Rodriguez , E.J. 
Herrera “Premature fracture in automobile leaf 
INTERNATIONAL RESEARCH JOURNAL OF MULTIDISCIPLINARY STUDIES 
& SPPP's, Karmayogi Engineering College, Pandharpur Organize  National 
Conference Special Issue March 2016 
 
Vol. 2, Special Issue 1, March, 2016   ISSN (Online): 2454-8499     Impact Factor: 1.3599(GIF), 
                                                                                                                                      0.679(IIFS) 
Web: www.irjms.in  Email: irjms2015@gmail.com, irjms.in@gmail.com       Page No: 5 
springs” Engineering Failure Analysis 648–655 -
2009 
[2] G Harinath Gowd E Venugopal Goud “Static 
Analysis Of Leaf Spring” International Journal of 
Engineering Science and Technology (IJEST) Vol. 
4 No.08 August 2012 
[3]  V. K. Aher , P. M. Sonawane “Static And 
Fatigue Analysis Of Multi Leaf Spring Used In The 
Suspension System Of LCV” International Journal 
of Engineering Research and Applications (IJERA) 
Vol. 2, Issue4, July-, pp.1786-1791 August 2012 
[4] Santosh Krishnaji Sindhe1, S. G. Bhatwadekar, 
V. V. Kulkarni, Satish Mullya “Static, Modal and 
Fatigue Life Prediction through CAE for a Leaf 
Spring used in Light Commercial Vehicle” 
International Journal of Science and Research 
(IJSR), Volume 2 Issue 3, March 2013 
[5] Sarika S. Yede M. J. Sheikh “Modeling and 
Finite Element Analysis of Leaf Spring” 
International Conference on Quality Up-gradation 
in Engineering, Science and Technology -2014 
 
[6]V.K.Aher,R.A.Gujar,J.P.Wagh&P.M.Sonawane 
“Fatigue Life Prediction of Multi Leaf Spring used 
in the Suspension System of Light Commercial 
Vehicle” International Journal on Theoretical and 
Applied Research in Mechanical Engineering 
(IJTARME) Volume-1, Issue-1, 2012 
 
[7]Y.S. Kong , M.Z. Omar, L.B. Chua, S. Abdullah 
fatigue life prediction of parabolic leaf spring under 
various road conditions” Engineering failure 
analysis 46pp 92-103 2014 
 
 
 
 
 
 
  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


Stress Analysis of Multi Leaf Spring by Using Experimental Method

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Stress Analysis of Multi Leaf Spring by Using Experimental Method

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