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.

  • In designing structures, it is critical to know the natural frequencies of the structure.
  • The prepreg consists of unidirectional (UD), continuous, high-elongation carbon fibres and an epoxy resin system.
  • A number of researchers have been developed numerous solution methods to analysis the dynamic behaviors of the laminated composite beams 14, 16, 19.
  • The stiffness values of the PPPP-untreated and PPPP-treated samples were significantly different, at which PPPP-treated were able to almost withstand 20% more impact content force.
  • The analysis can be applied to the laminated beam previously mentioned with the same dimensions and geometry.

Figure 4.

Contact force–displacement of the hybrid laminates at a ply orientation of ±45°8. Contact force–displacement of the hybrid laminates at ply orientations of 0°, 90°8. Figure 3 shows the force–displacement curve for the hybrid laminates at a ply orientation of 0°/90°8, while Figure 4 shows the force–time curves. On average, the hybrid laminates exhibited superior impact strength over the non-hybrid laminates. In comparison to the samples coated with natural fibre layers, the samples covered with high-strength carbon layers exhibited higher flexural strength at low impacts.

  • Yildirim, V. used the stiffness method for the solution of the purely in-plane free vibration problem of symmetric cross-ply laminated beams with the rotary inertia, axial and transverse shear deformation effects included by the first-order shear deformation theory.
  • 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.
  • 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.
  • These stacking patterns help in the evaluation of mechanical properties and modes of failure under different loading conditions.
  • Et al. gave analytical solutions for the free vibration problem of laminated composite beams.

Materials and Methods

The laminates were analysed using an IMATEK IM10 drop weight impact tester with an increment of 5 J until the samples were perforated. In practical applications, it means that if a torsional natural frequency excites the structure, the designer can change the material properties by changing the laminate stacking sequence, instead of re-design the complete structure. The analytical results by both classical lamination theory and shear deformation theory; the coupling effects queenwin casino review due to bending–twisting coupling stiffness result from fiber orientation and laminate stacking sequences are excluded.
This experiment utilised a 650 mm wide and 900 mm long glass mould to fabricate the composite. The resin content of the material is 35 ± 3% by weight, while the aerial weight of the fibre is 450 g/m2. The carbon/epoxy prepreg tape used in the experiment was sourced from Gurit Composite Company. The results revealed that the position of the lamina influences the impact response.

Figure 1.

Steel beams or columns totally encased in concrete are most common examples, while construction using steel beams as stiffeners of concrete plates is a quick, familiar and economical method for long bridge decks or for long span slabs. The theory includes the material coupling between the bending and torsional modes of deformations. The study of such free vibrations (free because the structure vibrates with no external forces) is very important in finding the dynamic response of the elastic structure. This condition is called resonance and to avoid resonance, the natural frequencies of the structure must be altered by making suitable adjustments in the design.

Figure 10.

Teh and Huang presented two finite element models based on a first-order theory for the free vibration analysis of fixed-free beams of general orthotropy. S. Irfan sadaq (contribution) Supported in fabrication of laminates. Stacking sequences inter-ply along with orientations (0°,30°,45°,60°,90°) are used. In the present work composites based on unsaturated polyester resin reinforced with pineapple leaf fibers (PALF) are studied.
The CPPC laminate demonstrated a significantly greater impact level at 20, 25, and 27.5 J for indentation (maximum), penetration, and perforation, respectively, compared to the PCCP laminate. Damaged areas of the PCCP at ply orientations of 0°/90°2, ±45°2s and ±45°2, 0°/90°2s. It was demonstrated that the PPPP-untreated polymer matrix could not properly distribute the impact load due to the hydrophobic nature of the polymer matrix, resulting in poor interfacial bonding between them . The PPPP-untreated exhibited no visible indentation compared to PPPP-treated with a mild circular indentation at the top side and a hairline crack propagated along the ply direction.

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In Figure 6, the PPPP-untreated and PPPP-treated laminates exhibited a similar force–displacement curve trend. Stiffness of the CPPC laminate was significantly higher than that of the PCCP laminate, at which CPPC laminate was able to almost withstand 30% more impact content force. The laminates were tested at varying energy levels with increments of 5 J until the samples were perforated. Due to the high potential of the PALF/carbon laminate composite, it is possible to explore its use in future applications. Consequently, the effects of the glass/natural fibre-reinforcement stacking sequence were also examined in various hybrid formulations with GFRP 30,31,32.

This behaviour could result from a random distribution of carbon fibres across the plies since the lamina geometry above and below the midplane are identical 35,36. Average flexural and tensile properties of the CFRP with different stacking sequences. However, one notable observation in this case (Figure 3a) is that the laminate spontaneous catastrophic failure occurred immediately after the maximum load was attained due to fibre breakage. Subsequently, the laminates experience a sudden drop in load due to failure within the internal plies, followed by continuous stress fluctuations at an increasing deformation rate. Five specimens per laminate with dimensions of 75 mm ×10 mm×3.5 (±0.1) mm, as shown in Figure 2c, were also tested on a Zwick Roell HIT25P pendulum impact tester with a working capacity of 7.50 J following the ASTM D6110 recommendation.