PSI - Issue 48

Muhammad Rizky Arga Wijaya et al. / Procedia Structural Integrity 48 (2023) 41–49 Wijaya et al. / Structural Integrity Procedia 00 (2019) 000–000

47 7

and glass laminate. Bamboo and wood veneer laminate exhibited better strength, fatigue life, and fracture resistance than birch laminate, and the characteristics were on par with glass-reinforced polymer laminate. Banga et al. (2015) demonstrated that 30% of bamboo in the laminate exhibited optimal mechanical properties and observed that particulate-filled bamboo-reinforced polymer had less water absorption than unfilled bamboo-reinforced polymer. Qin et al. (2009) studied the properties of bamboo material and experimented with life cycle analysis to compare the performance between bamboo turbine blades and glass fibre turbine blades. The results concluded bamboo material fulfilled the requirement of a wind turbine blade.

Table 6. Properties HDPE and green bamboo.

Young`s Modulus (GPa)

Ultimate Tensile Strength (MPa)

Fracture Toughness (MPa)

Percentage Elongation (%)

Material

Green Bamboo Recycled HDPE

1.2±0 .065

100.3 ± 11.28 16.80 ± 0.26

1.438×10 9

-

-

322.68 ± 33.4

0.0663 ± 0.010

Numerous types of research suggest that bamboo fibre composite has comparable properties to polymer composites. This study focuses on developing a composite material from bamboo fibre and recycled high-density polyethylene matrix for wind turbine blade fabrication—the material properties as shown in Table 6. Based on the depicted data in Table 7, the yield strength and the ultimate tensile strength of the tensile test experiment varies directly with the increasing percentage of fibre content in the composite. Recycled HDPE has stronger tensile strength than the remaining specimens, with a 25% bamboo fibre composition and 75% HDPE. It can then be concluded that the bamboo fibre and recycled HDPE composite possess desirable mechanical properties to be considered as material for wind turbine blade fabrication (Andoh et al., 2021).

Table 7. Range of modulus of elasticity, yield strength, and ultimate tensile strength for the samples.

Material

Modulus of Elasticity (MPa)

Yield Strength (MPa)

Ultimate Tensile Strength (MPa)

5.28±0.88

26.44 ± 0.56

25 % Green Bamboo + 75%

0.40±0.00

7. Natural composites: potential for wind turbine blades Natural fibres have the potential to be used to manufacture wind turbine blades, and the advantages of natural fibres are availability and environmental friendliness (Mishnaevsky et al., 2017). Bakri et al. (2016) examined the mechanical properties (tensile, impact, shear, flexural, and compression strength) of coir fibre composite; results concluded that its properties are similar to wood properties but inferior to glass fibre composite. Carbon/wood hybrids also offer unique material characteristics suitable for large turbine blades. The disadvantages are the raw fibres' quality variations, high moisture uptake, and low thermal stability. Holmes et al. (2019) tested a novel bamboo-poplar epoxy laminate for wind turbine blades. They demonstrated that this material has high strength and stiffness and can be used in wind blades instead of standard composites. Several potential materials are summarized in Table 8. To be conveniently used in industrial and mass-production scale, failure criteria, such as previously studied by Prabowo et al. (2020) and Carvalho et al. (2023) are highly recommended to be quantified and characterized.

Table 8. Properties of selected natural fibres.

Tensile Strength (MPa)

Elastic Modulus (GPa)

Status/Reference

fibre

Density (g/cc)

Elongation (%)

Ramie fibre Fique fibres Coir fibres

1.5

3.6–3.8 4.8–10.6

400–938 132–262

61.4–128

Potentially to be applied Potentially to be applied Potentially to be applied

1.47

3.9–7.9

1.2

30

593

4–6