Experimental and Computational Studies of Mono Composite Leaf Spring

Imperial Journal of Interdisciplinary Research (IJIR)
Vol-3, Issue-4, 2017
ISSN: 2454-1362, http://www.onlinejournal.in
Imperial Journal of Interdisciplinary Research (IJIR) Page 820
Experimental and Computational Studies
of Mono Composite Leaf Spring
Jaydip Popatrao Patil1 & Prof. V. J. Shinde2
1Bharati Vidyapeeth Deemed University's, College of Engineering, Pune
2Associate Professor, Bharati Vidyapeeth Deemed University's, College of
Engineering, Pune
Abstract: Safety, energy saving and environmental
protection square measure the vital trends just in
case of an automobile. Light-weight has become a
crucial goal of auto development. The spring is
concerning five-hitter to 100% of the overall mass of
vehicles because the vehicle suspension elastic
component. Thus spring is one amongst the vital
parts to attain vehicle light-weight. It will be simply
determined that material having lower modulus and
density can have a larger specific strain energy
capability. The introduction of composite materials
created it potential to cut back the burden of the
spring while not reduction of load carrying
capability and stiffness because of a lot of elastic
strain energy storage capability and high strength to
weight magnitude relation. A material with maximum
strength and minimum modulus of elasticity within
the longitudinal direction are going to be the
foremost appropriate material for a spring. To fulfill
the requirement of natural resources conservation,
automobile makers are trying to cut back the weight
of vehicles in recent years. Weight reduction will be
achieved primarily by the introduction of better
material, design optimization and better producing
processes. The suspension spring is one amongst the
potential things for weight reduction in vehicles
unsprung weight. This achieves the vehicle with a lot
of fuel efficiency and improved riding qualities. The
introduction of composite materials has created it
potential to cut back the weight of leaf spring with
none reduction on load carrying capability and
stiffness
Keywords- Leaf Spring, Composite Material,
Weight Reduction, Modulus of Elasticity, Elastic
Strain Energy
I. INTRODUCTION
Initially called “laminated” or “carriage spring”, a
leaf spring is a basic type of spring generally utilized
for the suspension in wheeled vehicles. It is
additionally one of the most established types of
springing, going back to medieval circumstances.
Now and then alluded to as a semi-elliptical spring or
cart spring, it appears as a slim curve molded length
of spring steel of rectangular cross-area. The center
point of the circular segment gives area to the hub,
while tie gaps are given at either end to connecting to
the vehicle body. For overwhelming vehicles, a leaf
spring can be produced using a few leaves stacked on
top of each other in a few layers, frequently with
continuously shorter takes off. Leaf springs can serve
finding and to some degree damping and additionally
springing capacities. While the interleaf friction
gives a damping activity, it is not very much
controlled furthermore, brings about stiction in the
movement of the suspension. Consequently
producers have tried different things with mono-leaf
springs.
A leaf spring can either be appended
specifically to the casing at both finishes or joined
straightforwardly toward one side, for the most part
the front, with the flip side connected to a shackle, a
short swinging arm. The shackle takes up the
inclination of the leaf spring to lengthen when
packed and along these lines makes for gentler
springiness. A few springs ended in an inward end,
called a spoon end (seldom utilized now), to convey
a swiveling part.
Fig. Conventional leaf spring
II. LITERATURE SURVEY
Kong et al. [1] have reproduced the fatigue life of
an parabolic leaf spring design under variable
amplitude loading (VAL). VALs convey the street
flag that incites fatigue disappointment on leaf
spring. With a specific end goal to look for thorough
leaf spring fatigue appraisal, VALs flag were
accumulated through estimations from different
street conditions, for example, expressway, bend
mountain street and harsh provincial region street.
Along these lines, fatigue life of specific leaf spring
configuration was anticipated utilizing finite

Imperial Journal of Interdisciplinary Research (IJIR)
Vol-3, Issue-4, 2017
ISSN: 2454-1362, http://www.onlinejournal.in
Imperial Journal of Interdisciplinary Research (IJIR) Page 821
dynamic (FE) stress–strain show together with VALs
motion as load information. For more moderate way,
Morrow and Smith Watson To per (SWT) mean
stress concentration techniques were additionally
connected. The outcomes demonstrate that fatigue
life of leaf spring is least amid harsh street mission,
trailed by bend Mountain Street and smooth
expressway street individually. Extra design
adjustment to drag out the fatigue life of the
parabolic leaf spring is mandatory. The street VALs
has given significantly more reasonable fatigue life
estimation of parabolic leaf spring design when
compared with traditionally controlled research
facility strategy. Parabolic leaf spring encounters
rehashed cyclic stacking amid working condition.
Fatigue life appraisal of the parabolic leaf spring is a
critical perspective amid the segment configuration
organize.
Malaga et al. [2] have concentrated the
substitution of multi-leaf steel spring with mono
composite leaf spring. Suspension system in a car
decides the riding comfort of travelers and the
measure of harm to the vehicle. The fundamental
capacity of leaf spring get together as suspension
component is to support vertical load, as well as to
isolate street actuated vibrations. The conduct of leaf
spring is complicated because of its clamping
impacts and between leaf contact and so forth. Since
the composite materials have more flexible strain
energy storing limit and high strength-to-weight
proportion when compared with those of steel. It is
conceivable to diminish the weight of the leaf spring
with no reduction on load conveying limit and
stiffness. Modeling and analysis of both the steel and
composite leaf springs have been done utilizing
analysis software.
The presentation of composite materials was made it
conceivable to decrease the weight of the leaf spring
with no reduction on load conveying limit and
firmness. Since, the composite materials have more
flexible strain energy storage limit and high strength
to-weight proportion when compared with those of
steel. The presentation of fibre reinforced plastics
made it conceivable to reduce the weight of a
machine component with no decrease of the load
conveying limit.
Murathan et al. [3] have concentrated the fibre
reinforced composite compared steel leaf springs
based on endurance rig tests. The traditional leaf
springs, intended for the improved performance
together with wellbeing dynamics, are made of steel.
However, it is viewed as that the steel leaf springs
are replaceed by lighter ones so as to satisfy the
predetermined prerequisites. Fibre reinforced
composite materials with polymer based matrix offer
an awesome potential for assembling leaf springs
with lightweight, high mechanical and fatigue
performance. Thusly, leaf spring makers have
extraordinary enthusiasm on those materials to
replace steel parts with the composite ones and an
expanding number of studies have been published in
literature in recent years. Leaf spring system
influences the weight of the vehicle notwithstanding
driving performance and security. Looking for
materials, which are lightweight and elite, rather than
steel has been proceeded as of late and it has been
quickened in most recent couple of years everywhere
throughout the world because of late directions.
Composite materials have the most astounding
potential to wind up distinctly an option applicant
material for this reason. Notwithstanding their
lightweight, composite materials are suited to
produce leaf springs because of their excellent
fatigue performance, higher corrosion and chemical
resistance and their procedure adaptability when
compared with steel.
Abdul Rahim Abu Talib et al. [4] showed that
composite elliptical springs can be utilized for light
and overwhelming trucks with substantial weight
reduction. Suspension system is intended to give
both safety and comfort to the vehicle occupants. In
this review, finite dynamic models were produced to
enhance the material and geometry of the composite
elliptical spring in light of the spring rate, log life
and shear push parameters. Fibre-reinforced
polymers have been vigorously created for some
applications, for the most part as a result of the
potential for weight savings. Different points of
utilizing fibre-reinforced polymers rather than steel
are: (a) the likelihood of decreasing noise, vibrations
and ride brutality because of their high damping
variables; (b) the nonattendance of corrosion issues,
which implies bring down upkeep expenses; and (c)
bring down tooling costs, which has good effect on
the assembling costs.
Mahmood and Rezaei [5] have examined
approach to acquire a spring with least weight that is
fit for conveying given static outer strengths without
failure. The finite dynamic comes about indicating
stresses and deflections checked the existing
analytical and experimental solutions. Utilizing the
result of the steel leaf spring, a composite one
produced using fibreglass with epoxy resin is
designed and optimized utilizing ANSYS. Principle
thought is given to the enhancement of the spring
geometry.. The design imperatives were stresses
(Tsai– Wu failure criterion) and displacements. The
outcomes demonstrated that an ideal spring width
decreases hyperbolically and the thickness
increments straightly from the spring eyes towards
the axial seat. Compared with the steel spring, the
improved composite spring has stresses that are
much lower, the natural frequency is higher and the
spring weight without eye units is about 80% lower.

Imperial Journal of Interdisciplinary Research (IJIR)
Vol-3, Issue-4, 2017
ISSN: 2454-1362, http://www.onlinejournal.in
Imperial Journal of Interdisciplinary Research (IJIR) Page 822
Gary and Khoa [6] have concentrated the
essentials of multi-leaf spring design as decided
through beam theory offers a general viewpoint on
how finite dynamic analysis functions. Furthermore,
the essentials of joining dissimilar materials require a
fundamental learning of how the consolidated
equivalent modulus influences the general stiffness
attributes of multi-leaf design. By catching these
essential things into finite dynamic modelling, an
analysis of a steel-composite multi-leaf contact
demonstrate with respect to an admired steel-
composite multi-leaf show demonstrates the
significance of contact demonstrating. The outcomes
exhibit the important difference between a idealized
non-contact models with respect to an entire contact
model.
S. Rajesh et al. [7] demonstrated that by
appropriately choosing the % of reinforcement and
its introduction it is conceivable to accomplish
higher order stiffness and thus higher natural
frequency. Actually not at all like homogenous
metallic material. GFRP composite will show
expanded stiffness with load application. At the point
when a seven leafs spring was replaced by mono
composite leaf spring under the static state of design
parameters and optimization, considerable weight-
reduction was accounted for. The joint strength
assumes an essential part in the working of leaf
spring in vehicle suspension. Leaf springs were
molded by short, and long glass fibre reinforced
polypropylene and unreinforced polypropylene and
the joint performance in both static and dynamic
conditions was surveyed. This review designs that
the likelihood of replacing existing traditional steel-
leaf spring by the leaf spring made by fitting the
layup of composite covers. The measurements of the
current traditional middle leaf (spring) of a business
vehicle were decided for the design and fabricate of
bite the dust for trim the composite takes off. In like
manner, suspension springs of composites of various
layups with glass and carbon were manufactured and
tried for flexure response. It is to be noted here that
the cross sectional region of the composite leaf
spring was the same as of the traditional leaf spring.
By utilizing universal testing machine, load per
deflection and greatest load for each of the composite
leaf springs were assessed. The low frequency affect
on the composite leafs was affected with a research
facility loading set-up in a milling machine. Test
comes about demonstrated the prevalent flexure
response of the hybrid composites and recommended
conceivable option on comparison with the
traditional spring.
Franklin and Edward [8] have explored the
conventional steel multi-leaf spring pack which has
been a minimal cost generally used suspension
system in vehicles for quite a long time. Applications
are commonly load conveying orientated, from light
trucks to overwhelming development gear. Upgrades
to the fundamental design as far as stress reduction,
fatigue resistance and noteworthy weight reduction
can be accomplished through the cladding of
composite material to the current steel spring Testing
was directed utilizing standard test strategies where
accessible to think about the strength of a standard
Multi leaf Steel Pack to a Hybrid Mono Leaf Spring.
The Hybrid Spring exhibited huge upgrades in the
area of extreme deflection, fatigue and creep
resistance. Testing to date affirms the advantage of
the lessened worry in the external most strands that is
a characteristic dynamic of the Fibreglass Mono-leaf
Hybrid Spring. In the area of car fluid presentation
the covering faired well, brake fluid bringing on the
most debasement. The gravel meter testing when
contrasting painted composite with the elastomeric
covering displayed enhanced outcomes.
Gulur and Sambagam [9] have concentrated
expanded enthusiasm of car industry in the replacing
of steel spring with fibreglass composite leaf spring
because of high strength to weight proportion. This
analysis contemplate designs to introduce a minimal
cost creation of finish mono composite leaf spring
and mono composite leaf spring with reinforced end
joints. Likewise, general review on the analysis and
design. A single leaf with variable thickness and
width for consistent cross sectional range of
unidirectional glass fibre reinforced plastic (GFRP)
with comparative mechanical and geometrical
properties to the multi-leaf spring, was designed,
created (hand-layup method) and tested. Computer
algorithm utilizing C-language has been utilized for
the design of steady cross-segment leaf spring. The
outcomes demonstrated that a spring width
diminishes hyperbolically and thickness increments
straightly from the spring eyes towards the hub seat.
The finite elements result about utilizing ANSYS
software demonstrating stresses and deflections were
checked with analytical and experimental outcomes.
The design imperatives were stresses (Tsai-Wu
failure criterion) and displacement. Compared with
the steel spring, the composite spring has stresses
that are much lower, the normal frequency is higher
and the spring weight is about 85 % bring down with
reinforced end joint and with finish eye unit.
J.P. Hou et al. [10] have depicted three designs
of eye-end connection for composite leaf springs.
The material utilized is glass fibre reinforced
polyester. Static testing and finite element analysis
have been completed to acquire the attributes of the
spring. Load– deflection curves and strain estimation
as a component of load for the three designs tried
have been plotted for correlation with FEA
anticipated values. The fundamental concern related
with the main design is the delamination failure at