The influences of fiber orientation are investigated by modeling laminated beams of different lay-up construction of clamped – free boundary condition as shown in Figure 1. The bending–torsion coupling due to stiffness coupling presented in composite beams due to fiber orientation and stacking sequence is neglected. Et al. studied the flexural–torsional behavior of thin-walled composite beams with closed cross-section and a number of nonclassical effects, such as material anisotropy, transverse shear, are considered in the study. This model is based on the classical lamination theory, and accounts for the coupling of flexural and torsional modes for arbitrary laminate stacking sequence. Lee and Kim studied free vibration of a thin-walled laminated composite beam, where a general analytical model applicable to the dynamic behavior of a thin-walled channel section composite is developed. Chandrashekhara and Bangera investigated the free vibration of angle-ply composite beams by a higher-order shear deformation theory using the shear flexible FEM.

Trash Pineapple Leaf Fiber Reinforced Polymer Composite Materials for Light Applications

The maximum force peak for the average stage increased by approximately 40% more than the PPPP-treated laminate. Chunhong et al. demonstrated that alkali treatment decreases surface polarity and exposes cellulose, increasing the number of potential reaction sites and contact regions between the PALF and matrix. Because of the hydrophilic character of PALF and the hydrophobic nature of the polymer matrix, they have weak contact bonding . The difference between them was that the PPPP-untreated laminate was penetrated at 12.5 J, whereas the PPPP-treated laminate was penetrated at 17.5 J. The PPPP-treated laminate revealed approximately 50% contact force higher than the PPPP-untreated, as shown in Figure 8. Even with a similar trend, the curve displacement is identically different due to the varying stacking sequences.
Furthermore, they can be incorporated into two or more reinforcing and filling materials in a single matrix of reinforcement and filling materials . From the results, It is seen that the clamped-clamped condition has a larger torsional frequency than other boundary fixations, and thus for all fiber angles. Each layer in the laminate has the same thickness.
These fibres can be utilised as another possibility to synthetic-fibres, resulting in more environmentally friendly composite products. Further research is required to study the compression and shear properties, which can play a vital role in further analysing the internal and interface failure of the laminates. An optical micrograph of the damaged laminate surface was used to explain the failure mode of queenwin casino review the composite. 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. On the other hand, LM2 exhibited high interlayer delamination between 0°/90° stacking configuration, as revealed in Figure 6. This behaviour has been reported in previous works on Charpy impact loading of composite 43,44,45,46,47.

• Likewise, the tensile stress (σt) and modulus (Et) of the composite were measured according to ASTM D3039 on a Shimadzu AGS-XD universal testing machine equipped with a 50 kN load cell, operating at a constant crosshead speed of 2 mm/min.
• Contact force–displacement of the hybrid laminates at ply orientations of 0°, 90°8.
• The CPPC laminate exhibited a similar rebound curve trend up to the maximum contact force.
• This variation in mechanical properties is due to different processing conditions, physicochemical properties of the materials, manufacturing techniques, the number of ply layups, laminate thickness, and testing conditions.
• Following the autoclave curing process, the responses of the composites to bending, tension and impact force were determined according to ASTM standards, and their corresponding strength, stiffness as well as impact energy were evaluated.
• The absorbed energy in quasi-isotropic laminates is equivalent to or slightly higher than that of cross- and angle-ply laminates.

Table 5.

Maximum contact force and displacement against impact energy of the hybrid laminates at a ply orientation of ±45°n. Maximum contact force and displacement against impact energy of the hybrid laminates at ply orientations of 0°/90°8. The impact behaviours of the hybrid laminates at varying ply orientations and stacking sequences are shown in Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9 and Figure 10. For this, the influences of ply angle as well as laminate stacking sequences on the torsional natural frequencies of the laminated beams with doubly symmetrical cross- sections are investigated. The torsional vibrations of the laminated beams are analyzed analytically based on the classical lamination theory, and accounts for the coupling of flexural and torsional modes due to fiber orientation of the laminated beams are neglected. An essential factor determining the type of failure exhibited by a composite laminate is the ply stacking sequence that also determines the orientation of the fibre 20,48,49.
Caminero, Rodriguez and Munoz studied the effect of stacking sequence on the Charpy and flexural damage of carbon fibre-reinforced polymer composite (CFRP) laminates. In this work, the effect of ply stacking sequence of carbon/epoxy laminates subjected to flexural, tensile and impact loading was investigated. PALF/carbon hybrid laminate composites have the potential to replace synthetic fibres due to their good mechanical qualities.

Table 2.

The unidirectional laminates have higher flexural and tensile strength compared to the cross-ply and quasi-isotropic laminates. Following the autoclave curing process, the responses of the composites to bending, tension and impact force were determined according to ASTM standards, and their corresponding strength, stiffness as well as impact energy were evaluated. Delamination is a fracture that occurs between plies with various fibre orientations in the matrix-rich region . When the applied impact energy is beyond a certain level, the matrix cracking reaches the maximum level, exceeding energy causing the second mode of internal damage mechanism, delamination . The density matrix cracking was predicted to be higher at interface bonding between carbon fibre and matrix than PALF and matrix.

Figure 8.

• The curves generally show the energy levels at which rebounding, penetration, and perforation occur during the impact test.
• It is observed that tensile strength and flexural strength of the laminate at orientation angle 30° attained highest strength compared with other orientation angle with an average percentage increment in the strength about 24%.
• Where a66 is element 6–6 of the laminate extensional compliance matrix (m/N)
• Make study intended to analyze free and forced vibrations of non-uniform composite beams in the Laplace domain.
• The torsional frequency for clamped-simply supported condition comes to be lower than clamped-clamped condition, then simply supported-simply supported comes to be lower than clamped-simply supported, and finally clamped-free condition comes to be lower than other supports.
• The laminate exhibits a fluctuated force–displacement curve at a high impact energy level.
• Laminates with varying stacking sequences have a lower energy-transfer rate and rupture when subjected to a higher load .

Sudarisman and Davies reported a maximum Ef of 61.10 GPa for a unidirectional carbon fibre-reinforced, epoxy laminate fabricated using an autoclave processing technology. In cross-ply laminate, this phenomenon initiates short delamination, which further coalesces within reinforcing plies, thereby causing instability propagation above and below the midplane of the laminates. Among all the configurations studied, LM1 with unidirectional fibre orientation (Table 3) is the most efficient in providing flexural resistance and stiffness, with an average flexural stress σf of 1100 MPa and modulus Ef of 98.40 GPa. The laminates were covered with the release film and breather before enclosing them in a vacuum bag, as shown in Figure 1. In a similar manner, the tensile properties of the composites were determined on a universal tensile machine, while their impact performances were measured using a pendulum impact tester. A three-point bending test was conducted to investigate the flexural properties of the laminates.
Jesthi et al. observed the influence of carbon glass fibre symmetric inter-ply sequence on the mechanical performance of polymer matrix composite. The randomly oriented crack patterns align with the laminates’ ply orientation, as shown in Table 4, Table 5 and Table 6. The interlinear interface between laminates with different ply orientations is weak . Consequently, a laminate with varied ply orientations limits energy transfer over its thickness and fails when subjected to higher loads . Both laminates exhibited the same impact level of indentation (maximum), penetration, and perforation, at 15, 17.5, and 20 J, respectively.

Both exhibited a circular penetration pattern at the top side and a crack opening on the bottom side. The penetration energy levels were 12.5 and 17.5 J for the PPPP-untreated and PPPP-treated, respectively. The penetration level was determined at the point of the greatest contact force and energy absorption. Table 4, Table 5 and Table 6 summarise the results of the investigations on the damage caused by the fracture of the impact. This could be because carbon has a higher failure strain than PALF due to its greater elongation.

At a glance: Figures

Thwe et al. described hybrid composites as reinforcing materials that combine multiple reinforcement fibres or matrices (blends) to provide strength and durability. Hybrid fibre-reinforced composites comprise at least one pair of two different fibres combined in a solitary polymer matrix, resulting in improved properties compared to a normal polymer composite. The laminate with different stacking sequences had a lower energy transfer rate and ruptured at higher impact energy. Finally this study is useful for the designer in order to select the fiber orientation angle to shift the torsional natural frequencies as desired or to control the vibration level. 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.
The stacking layering sequence in the composite structure is another factor that influences the impact strength in addition to ply orientation. Another investigation was performed by Sikarwar et al. on the impact response of woven glass fibre composites as a function of thickness and fibre orientation. The quality and strength of adhesion (bonding) within the fibre/matrix system are important components of the resistance of the composites to impact damage . Ply orientation in composites has a complex relationship with their impact damage resistance because of the multidirectional behaviour of the composite and the mechanism through which the damage propagates through the laminate.