Improvement of mode-Ⅱ interface mechanical properties of Al/GFRP composite laminates by VGCF

Vacuum resin infusion (VRI) is a promising technique for manufacturing complicated structural laminates. This high viscosity of nanofilled resin increases the filling time and leads to an incomplete mold filling. The mold filling time can be reduced either by making the fiber dimensions smaller than the mold (gaps around the fibers) or by adding ethanol to nanofilled epoxy. However, ethanol addition influences the mechanical properties of composite laminates. In this study, different amounts of ethanol (0.5 wt. % and 1 wt. %) were used as a diluent to both neat epoxy and epoxy filled with (0.25 wt. %) of titanium dioxide (TiO2) nanoparticles. From results, it was found that ethanol addition saves the time for neat and nanofilled epoxy by 47.1% and 24.1%, respectively. It was found that adding 0.5 wt. % of ethanol to 0.25wt. % of TiO2 nanoparticles (GT0.25E0.5) enhances the tensile and flexural strength by 30.8% and 55.9%, respectively compared with neat specimens. Furthermore, the tensile and flexural moduli increased by 62% and 72.3%, respectively. Furthermore, the mold filling time was investigated experimentally and validated numerically using ANSYS FLUENT software. The mold filling time prediction using ANSYS FLUENT can be used to avoid resin gelation before the incomplete mold filling and thus can be considered a cost-effective methodology. The results showed that the gaps around the fibers reduce the time by 178% without affecting the mechanical properties.

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Effect of fibre content on the mechanical properties of hemp fibre woven fabrics/polypropylene composite laminates

Polymers and Polymer Composites ◽

10.1177/09673911211023942 ◽

2021 ◽

pp. 096739112110239

Author(s):

Sheedev Antony ◽

Abel Cherouat ◽

Guillaume Montay

Keyword(s):

Mechanical Properties ◽

Polymer Matrix ◽

Composite Laminates ◽

Volume Fraction ◽

Fibre Volume Fraction ◽

Fibre Volume ◽

Woven Fabrics ◽

Fibre Content ◽

Viscoelastic Behaviour ◽

Hemp Fibre

Nowadays natural fibre composites have gained great significance as reinforcements in polymer matrix composites. Composite material based on a polymer matrix reinforced with natural fibres is extensively used in industry due to their biodegradability, recyclability, low density and high specific properties. A study has been carried out here to investigate the fibre volume fraction effect of hemp fibre woven fabrics/PolyPropylene (PP) composite laminates on the tensile properties and impact hammer impact test. Initially, composite sheets were fabricated by the thermal-compression process with desired number of fabric layers to obtain composite laminates with different fibre volume fraction. Uniaxial, shear and biaxial tensile tests were performed and mechanical properties were calculated. Impact hammer test was also carried out to estimate the frequency and damping parameters of stratified composite plates. Scanning Electron Microscope (SEM) analysis was performed to observe the matrix and fibre constituent defects. Hemp fabrics/PP composite laminates exhibits viscoelastic behaviour and as the fibre volume fraction increases, the viscoelastic behaviour decreases to elastic behaviour. Due to this, the tensile strength increases as the fibre content increases. On the other hand, the natural frequency increases and damping ratio decrease as the fibre volume fraction increases.

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Mechanical Properties in Notched AS-4/PEEK APC-2 Composite Laminates at Elevated Temperature

Journal of Composite Materials ◽

10.1177/0021998305056384 ◽

2005 ◽

Vol 40 (11) ◽

pp. 955-969 ◽

Cited By ~ 10

Author(s):

Ming-Hwa R. Jen ◽

Yu-Chung Tseng ◽

Shi-Chao Chang ◽

Ming Chen

Keyword(s):

Mechanical Properties ◽

Elevated Temperature ◽

Composite Laminates

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The Effect of High Glass Fiber Content and Reinforcement Combination on Pulse-Echo Ultrasonic Measurement of Composite Ship Structures

Journal of Marine Science and Engineering ◽

10.3390/jmse9040379 ◽

2021 ◽

Vol 9 (4) ◽

pp. 379

Author(s):

Sang-Gyu Lee ◽

Daekyun Oh ◽

Jong Hun Woo

Keyword(s):

Glass Fiber ◽

Composite Laminates ◽

Composite Structures ◽

Ultrasonic Waves ◽

Ship Structures ◽

Glass Fiber Reinforced ◽

Gfrp Composite ◽

Chopped Strand Mat ◽

Composite Ship ◽

Pulse Echo

Ship structures made of glass fiber-reinforced polymer (GFRP) composite laminates are considerably thicker than aircraft and automobile structures and more likely to contain voids. The production characteristics of such composite laminates were investigated in this study by ultrasonic nondestructive evaluation (NDE). The laminate samples were produced from E-glass chopped strand mat (CSM) and woven roving (WR) fabrics with different glass fiber contents of 30–70%. Approximately 300 pulse-echo ultrasonic A-scans were performed on each sample. The laminate samples produced from only CSM tended to contain more voids compared with those produced from a combination of CSM and WR, resulting in the relative density of the former being lower than the design value, particularly for high glass fiber contents of ≥50%. The velocity of the ultrasonic waves through the CSM-only laminates was also lower for higher glass fiber contents, whereas it steadily increased for combined CSM–WR laminates. Burn-off tests of the laminates further revealed that the fabric configuration of the combined CSM–WR laminates was of higher quality, prevented the formation of voids, and improved inter-layer bonding. These findings indicate that combined CSM–WR laminates should be used to achieve more accurate ultrasonic NDE of GFRP composite structures.

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Experimental and theoretical investigations into the mechanical properties of thermoplastic titanium-FRP hybrid composite laminates

10.14711/thesis-991012889468203412 ◽

2020 ◽

Author(s):

MohammadErfan Kazemi

Keyword(s):

Mechanical Properties ◽

Hybrid Composite ◽

Composite Laminates ◽

Theoretical Investigations

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Designing Composites for Graceful Failure

Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications ◽

10.1115/imece2020-23039 ◽

2020 ◽

Author(s):

Amany Micheal ◽

Yehia Bahei-El-Din ◽

Mahmoud E. Abd El-Latief

Keyword(s):

Mechanical Properties ◽

Energy Dissipation ◽

Composite Laminates ◽

Ultimate Load ◽

Low Cost ◽

Cost Effective ◽

Carbon Composite ◽

Three Point Bending ◽

Glass Carbon ◽

Effective Product

Abstract When inevitable, failure in composite laminates is preferred to occur gracefully to avoid loss of property and possibly life. While the inherent inhomogeneity leads to slow dissipation of damage-related energy, overall failure is fiber-dominated and occurs in a rather brittle manner. Multidirectional plies usually give a more ductile response. Additionally, stiffness and strength as well as cost are important factors to consider in designing composite laminates. It is hence desirable to optimize for high mechanical properties and low cost while keeping graceful failure. Designing composite laminates with hybrid systems and layups, which permit gradual damage energy dissipation, are two ways proposed in this work to optimize for mechanical properties while avoiding catastrophic failure. In the hybrid system design, combining the less expensive glass reinforced plies with carbon reinforced plies offers a cost-effective product, marginal mechanical properties change and ductile profile upon failure. Hybrid glass/carbon composite laminates subjected to three-point bending showed strain to failure which is double that measured for carbon composite specimens, without affecting the ultimate load. Energy dissipation mechanisms were also created by building laminates which were intentionally made discontinuous by introducing cuts in the fibers of the interior plies. This created a longer path for damage before cutting through the next ply resulting in double failure strain with marginal reduction in load. The effect of fiber discontinuity in terms of spacing and distribution are among the factors considered.

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