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4.7.1 The Effects of Stacking Sequence on Flexural Properties of E-glass/Basalt,

E-glass/Jute and E-glass/Flax

Hybrid composites have unique characteristics that can be used to meet the

design requirements with respect to strength and stiffness of the composite structure.
The arrangement of fibre within the hybrid is one of the vital factors in designing and

constructing hybrid composites. It was reported that the hybrid’s design strongly

affected a variety of properties such as a flexural strength, modulus fatigue behaviour,
impact performance and also highly dependent on the reinforcing fibre positions [151].

Present study shows that the hybrid laminates, which comprised two layers of
E-glass as a face sheet and three layers either basalt, jute or flax as a core, exhibit

higher flexural strength and modulus compared to IC sequence, as shown in Figure
4.8. The differences are considerably larger than in the case of tensile loading,

especially for laminates with basalt and jute fibres. This could suggest that the main
detrimental effect of IC would come from the decline of the compressive strength

compared to the tensile results, considering that the flexural loading implies tensile

loading on the lower side, and compressive loading on the upper side of the laminates.
Hence, the investigation revealed that the arrangement of fibres in a hybrid composite

structure strongly affects its flexural strength and modulus. This might be due to the

predominant compressive mode of failure on the laminate properties.

It is observed that wherever vegetable fibres were involved, such as in [40]

which focused on glass/coir fibre composites, small delamination were clearly forming
around the fractured coir fibres, but not around glass ones. The compressive mode is

also predominant in the case of basalt fibres, but not on carbon fibres [151]. As a matter
of fact, whenever there is a predominant, albeit localised, compressive loading such

as in falling weight impact tests, it is important to notice that selecting different fibres

for the core may have significant effects in delaying the onset of damages [156].
Another consideration that can be taken is the fact that using jute decreases the flexural

performance compared to flax, and the basalt is obviously superior, as observed
previously with other matrices such as polypropylene [67]. This is likely to be

attributed to the presence of fibrillation, or specifically, the separation of the different

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