الفهرس 
Definition of composite materials:14Only 14 pages are availabe for public view
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Abstract
Many of our modern technologies require materials with unusual combinations of
properties that cannot be met by the conventional metal alloys, ceramics, and
polymeric materials. This is especially true for materials that are needed for
aerospace, underwater, and transportation applications. Among these materials,
composite materials have been recently used in many different applications.
The effect of strain rate on the mechanical properties of glass fiber reinforced
polyester with and without Zinc Oxide (ZnO) nano-filler is studied. A woven
roving glass fiber reinforced polyester resin composite is fabricated by hand lay-up
method and tested under four different strain rates 0.01, 0.1, 1 and 6 s -1 with four
different ZnO percentages 0, 1, 2 and 3 wt.%. In addition, the fractured samples are
examined using Scanning Electron Microscope (SEM) to study the fractured
surface and fracture mechanism. Furthermore, finite element analysis is
implemented to analyze the experimental findings at different ZnO weight ratios
and different strain rates.
The results indicate an increase in the tensile stress with the increasing of strain
rates. The tensile strength of the glass fiber reinforced polyester composite also
increases with adding filler content up to 3 wt.%. In which the stress increases by
27% as the strain rate increases from 0.01 s -1 to 6 s -1 for 0% ZnO, 11.5% for 1%
ZnO, 40.5% for 2% ZnO, and 36% for 3 % ZnO. The SEM images show an
improvement on the fiber/matrix interfacial bonding at the highest strain rate and
with adding ZnO nano-filler with 3 wt.%. Also, the fracture mechanism changes
from delamination to fiber pull-out with increasing strain rate and filler content in
which the composite becomes more coherent. Furthermore, the finite element
results give good agreement compared to the experimental work results. In
addition, design of experiments confirms that both adding ZnO and strain rates
have significant effect on tensile stress of GFRP composite.