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.
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.
Figure 2
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 beams has been conducted by significant amount of research.
At a glance: Figures
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 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.
The Effect of Fiber Orientation and Laminate Stacking Sequences on the Torsional Natural Frequencies…
- The contact force–displacement curves for the laminates with ply orientations of ±45°2, 0°/90°2s are shown in Figure 9.
- The beams to be studied are orthotropic and its cross section has two axes of symmetry y and z.
- The laminates withstand high impact energy before penetration occurs at 25 J, followed by perforation at 27.5 J.
- 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.
- This explains why the elastic potential energy of the laminates is transformed into impactor kinetic energy, decreasing the absorbed energy .
- The results obtained after modeling the beams are presented in Figure 3.
- Khdeir and Reddy have been studied free vibrations of cross-ply laminated beams with arbitrary boundary conditions.
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).
Table 5.
At 5, 10, and 15 J impact energy, the laminates exhibited a rebound effect after the impactor contact force reached the peak force zone. Contact force–time of the hybrid laminates at ply orientations of ±45°2, 0°/90°2s. Contact force–displacement of the hybrid laminates at ply orientations of ±45°2, 0°/90°2s.
2. Tensile Properties
A previous study discussed the potential benefits of natural-synthetic fibre hybridisation and its implementation . This possibility makes once more these materials very attractive since it makes possible to obtain the desired torsional natural frequencies without increasing mass or changing geometry. This gives the designer one additional degree of freedom to design the laminate – the possibility to change fiber orientations in order to get more (or less) structure stiffness in torsion. Also, effects of boundary conditions on torsional natural frequencies are demonstrated.
- The mechanical properties for fiber and matrix are presented in Table 1 .
- From the results, it is clear that changes in fiber angle as well as laminate stacking sequences yield to different dynamic behavior of the component, that is, different torsional natural frequencies for the same geometry, mass and boundary conditions.
- Both exhibited a circular penetration pattern at the top side and a crack opening on the bottom side.
- Glass fiber (E-Glass) is used as reinforcement in the form of unidirectional fibers with epoxy resin as matrix for the laminated composite beams.
- Maximum contact force and displacement against impact energy of the hybrid laminates at ply orientations of ±45°2, 0°/90°2s.
- The maximum force peak for the average stage increased by approximately 40% more than the PPPP-treated laminate.
- Even though there are multiple orientation configurations, one could reasonably deem that transverse and off-axial detachment of the fibre significantly affects the overall resistance of the laminates.
Table 3.
Researchers studied the reactions of four different hybrid laminates under low-velocity impact loading 26,27. Quaresimin et al. observed that the queenwin casino review 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.
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.