TY  - JOUR
T1  - Mechanical Properties and Damage Analysis of Laminates with
Hybrid Fiber Volume Fraction
AU - G.B. Micheal, Amany 
JO  - Journal of Engineering and Applied Sciences
VL  - 15
IS  - 1
SP  - 165
EP  - 170
PY  - 2020
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2020.165.170
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2020.165.170
KW  - Laminate
KW  -fiber volume fraction
KW  -eignstress
KW  -failure
KW  -rigorous
KW  -loss
AB  - This study is concerned with modelling the mechanical behavior and damage of glass fiber
composite laminates that exhibit hybrid fiber volume fraction. The Transformation Field analysis (TFA) is
implemented in formulation while the composite is modeled using Mori-Tanaka averaging model. The
formulation is verified versus an experimental program conducted at the Center for Advanced Materials (CAM)
in the British University in Egypt (BUE). The studied laminates are with different lay ups and subjected to
uniaxial bending and tension. The investigated lay ups are (0°) glass fiber symmetric laminate with thickness
37.0 mm and consists of 48 plies and a (0/±45°) symmetric laminate comprised of 12 layers of (0/±45°) glass
fiber textile resulting in 36 plies with total thickness 10.7 mm. The fiber volume fraction (FVF) is 62% for both
lay ups. The hybridization in fiber volume fraction is implemented by assigning low FVF of 40% for some core
plies with variable depths. The core depths studied for the (0°) laminate are t/4, t/2 and 3t/4 where t is half the
thickness of the laminate while the core depths for the (0/±45°) layup are t/3 and 2t/3. A comparison according
to different criteria between the results of the above-mentioned lay ups and the results of the same laminate
when all plies have the same volume fraction of 62% is conducted. The comparison criteria include longitudinal
and flexural stiffness, the tensile strength and bending moment at the onset of failure together with ultimate
bending moment the laminate can sustain. For bending case, the results show that for both the (0°) and (0/±45°)
laminates, minor reduction in the mechanical properties in both the undamaged and damaged state takes place.
The reduction ranges from 0-12% for all recorded variables. For the axial tension, the loss in mechanical
properties is more rigorous. For the off-axis layup, laminate may lose 23% of its stiffness for large core depths.
The effect is more pronounced for the load capacity where the laminate may lose up to 30% of its strength
according to the depth of the low FVF core.
ER  -