19-03-2014, 04:30 PM
[u]DESIGN AND ANALYSIS OF COMPOSITE LEAF SPRING IN LIGHT VEHICLE[/u]
DESIGN AND ANALYSIS.pdf (Size: 236.68 KB / Downloads: 152)
ABSTRACT:
This project describes design and experimental analysis of
composite leaf spring made of glass fiber reinforced
polymer. The objective is to compare the load carrying
capacity, stiffness and weight savings of composite leaf
spring with that of steel leaf spring. The design constraints
are stresses and deflections. The dimensions of an existing
conventional steel leaf spring of a light commercial vehicle
are taken. Same dimensions of conventional leaf spring are
used to fabricate a composite multi leaf spring using E-
Glass/Epoxy unidirectional laminates. Static analysis of 2-
D model of conventional leaf spring is also performed using
ANSYS 10 and compared with experimental results. Finite
element analysis with full load on 3-D model of composite
multi leaf spring is done using ANSYS 10 and the
analytical results are compared with experimental results.
Compared to steel spring, the composite leaf spring is found
to have 67.35% lesser stress, 64.95% higher stiffness and
126.98% higher natural frequency than that of existing steel
leaf spring. A weight reduction of 76.4% is achieved by
using optimized composite leaf spring.
INTRODUCTION:
In order to conserve natural resources and
economize energy, weight reduction has been the main
focus of automobile manufacturers in the present scenario.
Weight reduction can be achieved primarily by the
introduction of better material, design optimization and
better manufacturing processes. The suspension leaf spring
is one of the potential items for weight reduction in
automobiles as it accounts for 10% - 20% of the unstrung
weight. This achieves the vehicle with more fuel efficiency
and improved riding qualities. The introduction of
composite materials was made it possible to reduce the
weight of leaf spring without any reduction on load
carrying capacity and stiffness.
SPECIFICATION OF THE PROBLEM
The objective of the present work is to design,
analyses, Glass Fiber/Epoxy complete composite leaf
spring with out end joints and composite leaf spring using
bonded end joints using hand-lay up technique. This is an
alternative, efficient and economical method over wet
filament-winding technique.
LEAF SPRINGS:
Leaf springs also known as flat spring are made out
of flat plates. Leaf springs are designed two ways: multi-
leaf and mono-leaf. The leaf springs may carry loads, brake
torque, driving torque, etc... In addition to shocks.
The multi-leaf spring is made of several steel plates
of different lengths stacked together. During normal
operation, the spring compresses to absorb road shock. The
leaf springs bend and slide on each other allowing
suspension movement.
CONCLUSION:
The development of a composite leaf spring having
constant cross sectional area, where the stress level at any
station in the leaf spring is considered constant due to the
parabolic type of the thickness of the spring, has proved to
be very effective.
The study demonstrated that composites can be used
for leaf springs for light weight vehicles and meet the
requirements, together with substantial weight savings.
The 3-D modeling of composite leaf spring is done
and analyzed using ANSYS.