Crushing Behavior of Woven Roving Glass-Epoxy Elliptical Composite Cones
Structure made from composite materials offers important characteristics such as weight reduction, design flexibility, and safety improvement. These composite materials provide higher or equivalent crash resistance as compared to their metallic counterparts and therefore find use in crashworthine...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English English |
| Published: |
2004
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| Online Access: | http://psasir.upm.edu.my/id/eprint/73/1/1000548979_t_FK_2004_13.pdf http://psasir.upm.edu.my/id/eprint/73/ |
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| Summary: | Structure made from composite materials offers important characteristics such as
weight reduction, design flexibility, and safety improvement. These composite
materials provide higher or equivalent crash resistance as compared to their metallic
counterparts and therefore find use in crashworthiness applications. The design of
various transport vehicles such as automobiles and aircraft for crashworthiness
requires collapse resistance of structural component and energy absorption
characteristics during collision.
This work examines the effects of composite elliptical cone vertex angles on crushing
behaviour, energy absorption subjected to quasi-static compressive load, and the
capability of natural fibre composite as filler material. The composite elliptical cone
walls were fabricated from woven roving glass fibre with orientation of [0/90] and
epoxy. Since natural fibre composite materials are increasingly being utilised in
automotive parts for their relatively high strength and stiffness to weight and cost
ratios, chopped oil palm frond fibres mixed with resin in the form of foam were used
in this study as fillers. The composite elliptical cones with vertex angles varying from
0º to 24º in 6 increments fabricated for axial compression tests with the cone bottom
end dimension of ab = 74mm (inner major radius) and bb = 53mm (inner minor
radius); 165mm high and 5mm thick were fixed for all the specimens. Different cone
vertex angles (β) of the elliptical cone resulted in different dimension of cone top end
i.e. at (inner major radius) and bt (inner minor radius). The composite elliptical cones
fabricated and tested were of six layers.
Thirty specimens were fabricated, fifteen of which were filled with chopped oil palm
frond fibres. The load-deformation and the energy-deformation relations as well as
the deformation history and failure modes for the composite elliptical cones with
various vertex angles tested under quasi-static axial crushing load are presented and
discussed. The load-deformation curves presented were obtained from averaging the
load-deformation points for three replicated tests with identical elliptical cone and
testing conditions. In addition, the effects of cone vertex angles, filling on the load
carrying capacity and the energy absorption capability are discussed.
The results showed that the quasi-static axial crushing behaviour of elliptical woven
roving laminated composite cones is strongly affected by their structural geometry,
the specific energy absorbed by the composite elliptical cones with the vertex angles
of 6º, 12º, 18º, and 24º, both the empty and the filled with natural fiber, which is
more than that in an elliptical cone with the vertex angle of 0º (the elliptical tube) at
any given deformation.
On the other hand, empty core elliptical composite cones were better in specific
energy absorption than those filled with natural fibre. The specific energy absorption
for elliptical composite cone showed positive correlation i.e., the more the angle
increases the more energy is absorbed. In this regard, the empty elliptical composite
cone with 24º angle exhibited the best energy absorption capability. |
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