Characterization of physical, mechanical and morphological properties of unstitched and silk fibre-stitched woven Kenaf reinforced epoxy composites
Over the past decade, natural fibers (NFs) have attracted great attention to replace synthetic fibers in fiber-reinforced polymer composites owing to their acceptable mechanical properties, light weight, low cost, and biodegradability. In transportation sections, NFs are used to fabricate various...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/104209/1/YASIR%20KHALEEL%20IBRAHIM%20KERMASHA%20-IR.pdf |
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| Summary: | Over the past decade, natural fibers (NFs) have attracted great attention to
replace synthetic fibers in fiber-reinforced polymer composites owing to their
acceptable mechanical properties, light weight, low cost, and
biodegradability. In transportation sections, NFs are used to fabricate various
car components, such as door panels, car roofs, dashboard components,
mats, and wheels. In sports goods, several types of equipment such as
surfboards, windsurfing boards, tennis rackets, badminton rackets, and golf
clubs are fabricated using NFs. In general, fiber composites have poor
through-thickness mechanical properties due to the absence of a z-direction
binder. This problem becomes more critical with the use of NFs due to their
lower strength compared to synthetic fibers. Stitching is a through-thickness
toughening method, which is used to introduce fibers in the z-direction and
achieve better through-thickness mechanical properties. The present study
aimed to determine the mechanical properties of unstitched and silk fibrestitched
woven Kenaf-reinforced epoxy composites. The woven Kenaf mat
was stitched with silk fibre using a commercial sewing machine. The stitching
length (SL) and stitching row (SR) spacing were five millimeters. The fivemillimeter
stitching parameters were selected to make the stitching process
easier by a commercial sewing machine and to minimize the damage to the
stitched fiber. The specimens were fabricated using a hand lay-up method.
In total, three specimens were fabricated (one unstitched and two silkstitched)
with different stitching orientations. Following that, the specimens
were cut in accordance with the standards of the American Society for
Testing and Materials (ASTM), including ASTM D3039, ASTM D790, and
ASTM D256 for tensile test, flexural test, and the Izod impact test,
respectively. The tensile and flexural tests were conducted using an Instron
3365 universal testing machine, and the Izod impact test was performed
using an Instron CEAST 9050 testing machine. The results indicated that the
stitched specimens had comparable in-plane mechanical properties to the
unstitched specimens. In the tensile mechanical test, the stitched specimens
showed similar and 17.1% higher tensile strength compared to the unstitched
specimens. The flexural mechanical test also demonstrated a 9% decrease
in the flexural strength of the stitched specimens compared to the unstitched
specimens. On the other hand, the Izod impact mechanical test showed a
significant improvement by 33% in the stitched specimens compared to the
unstitched specimens, which confirmed that stitching could successfully
enhance out-of-plane mechanical properties. Overall, the findings of this
research indicated that the stitched specimens had better mechanical
performance compared to the unstitched specimens, and the reduction of the
flexural strength was not significant as opposed to the considerable
improvement of the impact strength. |
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