03-08-2012, 04:55 PM
Mono Composite Leaf Spring for Light Weight Vehicle
Mono Composite Leaf Spring for Light.pdf (Size: 457.97 KB / Downloads: 82)
INTRODUCTION
In order to conserve natural resources and economize
energy, weight reduction has been the main focus of
automobile manufacturer 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 automobile as it accounts for ten to
twenty percent of the unsprung weight. This helps in
achieving the vehicle with improved riding qualities. It is
well known that springs, are designed to absorb and store
energy and then release it. Hence, the strain energy of the
material becomes a major factor in designing the springs.
SPECIFICATION OF THE PROBLEM
The objective of the present work is to design, analyse,
fabricate and testing of unidirectional Glass
complete mono 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
[1]
DESIGNS AND FABRICATION OF COMPOSITE MONO LEAF SPRING
Considering several types of vehicles that have leaf
springs and different loading on them, various kinds of
composite leaf spring have been developed. In multi-leaf
composite leaf spring, the interleaf spring friction plays a
spoil spot in damage tolerance. It has to be studied
carefully.
The following cross-sections of mono-leaf composite
leaf spring for manufacturing easiness are considered.
1. Constant thickness, constant width design.
2. Constant thickness, varying width design.
3. Varying width, varying thickness design.
In this paper, only a mono-leaf composite leaf spring
with varying width and varying thickness is designed and
manufactured. Computer algorithm using C-language has
been used for the design of constant cross-section leaf
spring. The results showed that a spring width decreases
hyperbolically and thickness increases linearly from the
spring eyes towards the axle seat.
Fabrication Process
The constant cross section design is selected due to its
capability for mass production, and to accommodate continuous
reinforcement of fibers and also it is quite suitable
for hand lay-up technique.
Many techniques can be suggested for the fabrication
of composite leaf spring from unidirectional GERP. Composite
leaf spring was fabricated using wet filamentwinding
technique [1]. In the present work, the hand lay-up
process was employed.
The templates (mould die) were made from wood and
plywood according to the desired profile obtained from the
computer algorithm. The glass fibers were cut to the desired
lengths, so that they can be deposited on the template
layer by layer during fabrication. In the conventional hand
lay-up technique, a releasing agent (gel/wax) was applied
uniformly to the mould which had good surface finish.
This is followed by the uniform application of epoxy resin
over glass fiber. Another layer is layered and epoxy resin is
applied and a roller was used to remove all the trapped air.
This process continued till the required dimensions were
obtained.