Page 76 - Template Tesis UTM v2.0

Israr et al. [91] investigated the damage behaviours of the pure bamboo under

quasi static indentation test with the aid of Linear Variable Differential Transformer
(LVDT) apparatus to monitor the accuracy of specimen’s displacement. In this study,

two similar specimens of the pure bamboo were tested, marked as B1 and B2. Both
specimens were indented up to maximum of 8.0 mm and the load was unloaded

automatically after reaching this point. From load-deflection curves, it was observed
that the load sustained by the specimen seemed to increase gradually with the increase

in displacement. For further investigation, both specimens were retested at the same

spot and it was observed that sample B1 recorded the decreasing peak load from 950
to 900 N while B2 shows a small increment. Based on SEM images, there was no

significant difference for the damage from first and second impact of B2 on the
permanent indentation. However, sample B1 was broken into two pieces in the second

re-indentation after the displacement reached 7.8 mm. It might be due to the drastic
propagation of the intra-laminar damage in the fibre direction and the presence of

trapped debris resulting from fibre breakages as illustrated in Figure 2.20. From

microscopic view, pure bamboo experienced the same damage as conventional
composites such as fibre breakage and delamination. Nevertheless, the permanent

indentation only occurred on the indented area without affecting non-indented regions.

It indirectly indicated that bamboo fibre is a ductile material with high fracture
toughness and higher energy absorption capacity.

Fibre crack

Debris

Delamination

Figure 2.20 SEM image of internal surface of bamboo fibre [91]

Carbon fabric/epoxy with two types of stacking sequences were investigated

on quasi static indentation loading, namely SC1 and SC2. SC1 and SC2 were
constructed with the sequence of [0/90, ±45, Core, 0/90, ±45] and [0/90, ±45, 0/90,

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