Effects of Ply Orientations and Stacking Sequences on Impact Response of Pineapple Leaf Fibre PALF Carbon Hybrid Laminate Composites

The machine was outfitted with a 9.68 kg impactor and a hemispherical impact head with a diameter of 10 mm and a mass of 0.71 kg. The PALF and carbon plies were layered on the glass surface and protected by a plastic layer. The load–deflection curves and photographs of the damaged samples acquired from the impacted and non-impacted sides were compared to determine the failure processes of the damaged specimens for various impact energies. The leaf produces a lot of cellulose fibre, with cellulose making up the majority (70–82%) and lignin (5–12%) and ash making up the remainder (1.1%) . PALF is the most often used fibre in the textile industry for various reasons, including its abundance, low cost, superior thermal and acoustic insulation, exceptional tensile strength, and high toughness. One of the best options for natural reinforcement fibre is pineapple leaf fibre (PALF), a massive amount of biomass waste abundantly available in tropical countries .

The Effect of Fiber Orientation and Laminate Stacking Sequences on the Torsional Natural Frequencies…

Five laminates with different stacking configurations were produced using the hand-laying-up technique. Typically, this manifests as matrix breaking and bonding between the fibre and the matrix . The in-plane extensorial force, which is anisotropic, affects the fracture behaviour of the laminates 63,64.

• Figure 12, Figure 13 and Figure 14 illustrate the force–displacement and maximum force–displacement curves, respectively, for the laminates with ply orientations of 0°/90°2, ±45°2s.
• When 0° plies are substituted with 90° plies, as in the case of LM2 and LM3 layup, the number of carbon fibres parallel to the longitudinal loading of the composite decreases, resulting in lower modulus and tensile strength than LM1.
• As can be seen, the unidirectional laminate, LM1, absorbed lower energy (92.10 kJ/m2) compared to the multidirectional, LM2 (102.21 kJ/m2), LM3 (109.40 kJ/m2), LM4 (116.2 kJ/m2) and LM5 (115.12 kJ/m2) laminates.
• Subsequently, UD prepreg tape was cut into sections of approximately 400 mm by 450 mm before laying up each ply with varying stacking patterns into the mould by hand.
• All the samples with different stacking orders were tested for their flexural strength.
• The bending–torsion coupling due to stiffness coupling presented in composite beams due to fiber orientation and stacking sequence is neglected.
• Several researchers have dealt with torsional vibration of beams.

Table 3. Torsional natural frequencies (Hz) for different stacking sequences laminate

Table 5 lists the damaged areas of the PCCP and CPPC laminates at ply orientations of 0°/90°8. Damaged areas of the PPPP-untreated and PPPP-treated laminates at ply orientations of 0°/90°8. The indentation (maximum) indicates the impact energy level before the laminates were penetrated during the test. The interlinear interface between laminates with various ply orientations is mechanically weak due to a mismatch in the bending deformations of adjacent plies . This phenomenon is further explained by the fact that the energy in a composite laminate can easily be passed from one ply to the next if stacked in the same order . The absorbed energy in quasi-isotropic laminates is equivalent to or slightly higher than that of cross- and angle-ply laminates.

Materials and Methodology

The results were comparable to those of other polymer composites reinforced with natural and synthetic fibres . However, the flexural modulus was based solely on the specimens’ volume percentage of carbon fibre. The perforation threshold of the hybrid composite with a carbon face sheet was 30% more than that of the hybrid composite with a glass face sheet.

Table 2.

• Ply orientation is important in designing composite laminates to withstand high-impact loads.
• The fracture pattern was also identical at each impact level; however, the direction of crack propagation varied due to different ply orientations.
• Likewise, LM3 displayed a similar mode of failure as LM2 but minimal interlayer delamination due to the symmetry and balanced nature of the cross-ply laminate.
• Qiao Pizhong and Zou Guiping presented an analytical study for dynamic behavior of pultruded fiber-reinforced plastic (FRP) composite cantilever I-beams based on a Vlasov-type linear hypothesis.
• Five samples from each laminate were tested to ensure the reliability of the result.
• The laminated beam is modeled and analyzed by the FEM.
• CPPC demonstrated less distortion because of the presence of carbon in the exterior layer.

Contact force–displacement of the CPPC laminate at a ply orientation of ±45°8 at an energy level of 10 J. Figure 2 shows an example of the contact force–displacement curves of the CPPC laminate with a ply orientation of ±45°n at an energy level of 10 J. The laminates were fabricated using plain-weave PALF (185 GSM), twill weave carbon fibre mat (200 GSM), EpoxAmite 100 epoxy resin (epoxy polymer (ether of bisphenol A)), and a hardener (triethylenetetramine). In previous studies, complete investigations of PALF as reinforcement for polymer composites and the mechanical characteristics of the hybrid laminate composite were performed 15,33,34,35. Hybrid laminates with glass fabric in the outer skin (skin) exhibited higher impact strength than laminates with glass fabric in the core (core).

Researchers studied the reactions of four different hybrid laminates under low-velocity impact loading 26,27. Quaresimin et al. observed that the impact energy absorption capabilities may be affected by the thickness and fibre orientation, with a 0°/45° interface demonstrating the least impact damage. Natural-synthetic fibre hybrid composites have been the subject of previous research, which mostly focused on reducing the use of synthetic fibres 8,9.

In general, damage to the top surfaces manifests as circular indentations caused by the descending hemispherical head, with the depth of this depression increasing with increasing impact energy. Laminates with varying stacking sequences have a lower energy-transfer rate and rupture when subjected to a higher load . The energy absorbed by the local deformation decreases due to the stiffness of the carbon outer layer, resulting in a more brittle fracture . Even though CPPC could withstand more impact energy than PCCP, it demonstrated a slightly lower absorbed energy.
Et al. used the dynamic stiffness analysis and the first-order shear deformation theory to study the free vibration of laminated beams. Abramovich and Livshits studied the free vibration of non symmetric Cross-ply laminated Composite Beams based on Timoshenko type equations. Investigated the free vibrations of axially loaded composite Timoshenko beams using the dynamic stiffness matrix method by developing an exact dynamic stiffness matrix of composite beams taking into account the effects of an axial force, shear deformation, and rotatory inertia. Free vibration analysis of laminated queenwin casino review beams has been conducted by significant amount of research.
The impact resistance of the GFRP laminates was higher than that of hybrid laminates. The low-velocity impact testing by Sarasini et al. investigated the damage tolerance of carbon/flax composites to determine their failure. Two types of hybrid composite plates (glass–carbon/epoxy) were subjected to impact tests until they were completely perforated.
Therefore, a hybrid synthetic with natural fibres was introduced to ensure environmental sustainability and reduce the carbon footprint. Carbon-fibre-reinforced polymer (CFRPs) composites are widely used in modern industries because of their superior mechanical strength . Through visual inspection, delamination was observed to occur at the interfaces of different stacking sequences and ply orientations. This investigation reveals that the overall impact properties of PALF and carbon as reinforcements were improved by a beneficial hybridised effect.