Experimental Evaluation of Mode I and Mode II Fracture Behavior of Glass Fiber Reinforced Polymer Composite by Considering Different Environmental Aging
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Date
2020-06
Authors
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Publisher
Addis Ababa University
Abstract
The influence of different environmental aging on mode I and mode II interlaminar fracture
resistance of glass fiber reinforced polymer composite material is experimentally studied in this
paper. Test specimens of unidirectional E-glass fiber with epoxy resin as a matrix material are
used in this study. The manufacturing techniques include hand layup process that assisted with
vacuum bagging system. Double cantilever beam (DCB) specimens for mode I and end-notched
flexure (ENF) specimens for mode II loading conditions are used to realize the test. These
specimens were categorized to be immersed in pure water, saline water, engine oil and benzene
environments for different period of time to visualize the effects. Through this comparison, the
mode I interlaminar resistance ���� = 50.8 ��/��
, which is the maximum one, is resulted in the
normal specimen test. The other fracture resistance, which is decreased by 10.27% from the
normal condition specimen, is observed in 15
2
day engine oil immersion. On the other hand, in
mode II fracture resistance the maximum value of ������ = 2.49 ��/��
th
is obtained in specimens
immersed for 30
2
was seen
in specimens tested from 15
th
day in benzene media. The other proportionate result ������ = 2.29 ��/��
2
day pure water media. While in the normal condition specimens, the
fracture resistance obtained is ������ = 1.58 ��/��
th
. The result of the experimental work showed that,
the resistance to fracture of environmentally exposed specimens are lower compared to the normal
specimens in a DCB test. This can be interpreted as the distribution of such environments on the
exposed specimens facilitates the dislocation of the mating matrix and hence increases the opening
of the laminate. While, in the mode II loading condition, the exposed specimens are in good
performance of resistance to delamination compared to the normal. Again, this is the reason
behind the absorbed particles help to increase the flexural strength of the immersed specimens.
Description
Keywords
Glass Fiber, Epoxy Resin, Environmental effect, Delamination, Fracture resistance