Drying performance, as well as physical and flexural properties of oil palm wood dried via the super-fast drying method

Effects of incising parameters were studied relative to the drying performance and properties of super–fast dried oil palm wood. Different incising depths (1/3, 1/2, 2/3, and 100% of the total thickness) and distance (38 mm and 50 mm) were made on the oil palm wood boards prior to the super-fast drying procedure. All the boards achieved the desired moisture content after drying. Drying defects were minimal, as only two boards indicated end checks and surface checks defects. The board density ranged from 0.44 g/m3 to 0.60 g/m3, and the thickness swelling and water absorption of the boards ranged from 8.3% to 12.5% and 45% to 67%, respectively. The specific modulus of rupture and elasticty ranged from 0.35 N m3/kg mm2 to 0.77 N m3/kg mm2 and from 77.64 N m3/kg mm2 to 118.40 N m3/kg mm2, respectively. It can be concluded that the hole distances did not exert significant effect on the properties, with exception of specific modulus of elasticity. A hole depth of 1/3 mm was preferable, since the surface looked like no incision had been made and the sample had good physical and flexural properties.

Multiscale Evaluation of The Elastic Behavior for The Metal-Coated Lattice Structures

Well-developed Additive Manufacturing leads to a variety of material and structure design. With the combination of 3D printing and plating technique, metal-coated resin lattice is investigated to achieve a light weight design with minimal economic cost and admirable material properties. In this paper, numerical approaches integrated with classical homogenization theory is adopted to study the effective mechanical characterizations of the BCC (Body-Centered-Cubic) metal-coated lattices. The selection of RVE (Representative Volume Element) is discussed for obtaining objective effective properties. Moreover, the impact of unit cell rod diameter and coating film thickness are investigated. A sensitivity analysis of these two parameters is conducted based on the advanced hypercube sampling methods. The results reveal that multiple-unit-cells lead to more stable homogenized properties than single unit cell. The Increase of volume fraction may improve the elastic modulus and specific modulus remarkably. However, the increase of thickness of coating film only leads to monotonously increased elastic modulus. For this reason, there exists an optimal coating film thickness for the specific modulus of the lattice structure.

Co-gel strategy for preparing hierarchically porous silica/polyimide nanocomposite aerogel with thermal insulation and flame retardancy

Co-gel strategy for preparing hierarchically porous silica/polyimide aerogel with low density, high specific modulus, hydrophobicity, flame retardancy, and thermal insulation.

Consequence of cenosphere loading on hygrothermal, thermal, and mechanical properties of epoxy syntactic foams

Epoxy syntactic foams with different compositions of cenosphere were fabricated and characterised. The effect of loading cenosphere in epoxy syntactic foams was analysed. Good thermal stability of cenosphere–epoxy syntactic foams was established from the thermogravimetric analysis results. The completion of cure reaction at ambient temperature conditions was ascertained from differential scanning calorimetry results. Dynamic mechanical analysis revealed 114°C as the glass transition temperatures ( Tg) for neat epoxy sample, which increased to 132°C with 50% loading of cenosphere. Cenosphere-filled epoxy syntactic foams had low density and low water absorption values when compared to the neat epoxy sample. Homogeneous distribution of the cenosphere particles was confirmed using scanning electron microscopy. The compression studies confirmed brittle failure of the syntactic foams. This was also supported by the scanning electron microscopic images. The incorporation of hollow cenosphere particles led to a decrease in the flexural strength. Syntactic foams with 30% loading of cenosphere exhibited best specific modulus and specific strength. The specific strength increased by 24% for T30 sample and specific modulus increased by 36% for T30 samples when compared to the neat epoxy sample. As the need for strong but lightweight thermally stable products is continually increasing, there is a great possibility for the utilisation of these cenosphere–epoxy syntactic foams as lightweight core for sandwich composites.

Mechanical Properties of Natural Bamboo due to Tensile and Compression Loadings

This paper deals with mechanical properties of natural bamboo (Gigantochloa pseudoarundinacea and Gigantochloa apus). Tensile and compression tests were done on these bamboo. It shows that Gigantochloa pseudoarundinacea is better in the field of strength and modulus compared with Gigantochloa apus. Further analysis shows that the specific modulus and strength of these bamboo are better compared the data available in the literature, and even better compared with traditional engineering materials, such as mild steel, polyester resin or Glass Reinforced Plastics. Two parameter Weibull analysis were used to analysis the experimental data.

Green Composites for Potential Substitution of E-Glass Composites and Plastics

This chapter provides a comparative study of the mechanical properties for different natural fiber composites. These composites consist of natural fiber 8-harness stain weave fabric reinforcing an epoxy matrix. The analytical model discussed in Chapter 5 is used to evaluate the elastic and ultimate strengths properties. The comparison is made according to the calculated specific modulus and specific strength. The Natural Fiber Reinforced Polymer (NFRP) composites are compared together according to their categories and yet compared to a similar E-glass/epoxy composite. In addition, a polypropylene and a thermoplastic composite are used also as reference materials. It is shown that some NFRP especially those belonging to the Bast and Leaf categories provide better properties than the plastics and also the E-glass/epoxy composite. Overall the Flax/epoxy composite could be considered the optimum choice in terms of properties since it has high specific modulus and strength.