Papers by Keyword: Composite Material

Abstract: As part of a sustainable development approach, global energy consumption continues to rise, fueled by industrial development and rapid urbanization. This growth poses major challenges in terms of increased demand for buildings, which in turn leads to a significant increase in energy demand, making it essential to assess the consequences of this increased energy consumption on the climate and identify viable alternatives. Enhancing energy efficiency is crucial for minimizing our carbon footprint. By implementing measures to optimize the use of energy resources. Currently, the construction industry is seeking to reduce energy consumption by designing and manufacturing more environmentally-friendly and sustainable building materials. In this work we studied the thermal behavior of a building, in Atlantic climate, constructed with a composite material based on alfa fibers using TRNSYS software. The results show that the energy performance of the investigated building is improved by 17% for cooling and 23% for air-conditioning.

Abstract: Dedicated metal armor protection for land transport vehicles is an effective solution against blast threats. However, the added weight of these solutions can reduce the vehicle's maneuverability and, indirectly, its maximum payload capacity. To overcome this weight problem, the use of composite materials as additional armor for the vehicle can be an innovative and lightweight solution. In previous studies, different configurations have been subjected to the blast effect in order to analyze and understand their dynamic behavior. The first fiber reinforcements used for composite materials, based on stacked layers of E-glass fabric, were able to withstand dynamic blast loads. However, these reinforcements tend to have the same performance as the all-steel solution for the same areal weight. Therefore, the objective of this study is to investigate the use of 3D woven fiber reinforcements based on E-glass yarn in composite materials for better dynamic performance under blast loading. The fabricated targets were tested against the same blast threat in a free field configuration. The distance between the charge and the targets was kept constant (except for the full thickness 3D woven composite). During the blast, the dynamic deformation in the thickness direction was recorded and different targets were compared. According to the resulting dynamic deformation under the impact of the blast, a better performance of the full thickness 3D woven composite material matched with the protective steel plate was revealed.

Abstract: Marine soils containing shell fragments are typically found in coastal areas and pose a significant problem as they are highly compressible, have low shear strength and settle heavily, hindering infrastructure development. Conventional stabilization methods are often costly and pose a problem for the environment. Alternative solutions are therefore needed to improve the strength of marine soils by sustainable means. Hence, the main aim of this study is to investigate the effectiveness of cockle shell powder (CS) and nanosilica powder (NS) as sustainable stabilization materials to improve the strength properties of soft marine soils. To achieve this, multi-stage consolidated undrained (CU) triaxial tests were conducted on both untreated and treated soil samples, with 0.7% NS, 10% CS and a combined mixture of 10% CS and 0.7% NS. The tests were conducted under different pressure ratios to determine key strength parameters, including cohesion (c) and internal friction angle (φ). The results showed that the treated soils exhibited a significant increase in strength compared to the untreated samples, with improvements of up to more than 50%. The ANOVA results revealed that the inclusion of cockle shell powder and nanosilica powder had a statistically insignificant influence on the cohesions and friction angles of the treated soils due to the limited number of samples tested under each treatment condition. Furthermore, the multi-stage CU method proved to be efficient in estimating strength parameters while minimizing material consumption and testing time, promoting an environmentally friendly approach to soil improvement in marine environments.

Abstract: Natural fibre composites are gaining importance in engineering and automotive sectors due to their sustainability, lightweight nature, and cost-effectiveness. However, their flexural modulus and other mechanical properties require enhancement to meet industrial standards. This study aims to improve the performance of hybrid composites reinforced with hemp, jute, and coir fibres in an epoxy matrix. Specimens were fabricated using the hand lay-up technique followed by compression moulding and tested according to ASTM standards. Mechanical characterization included hardness, tensile, flexural, compressive, and impact tests, along with water absorption analysis. The results demonstrated significant improvements, with maximum hardness of 80 HRM, tensile strength of 16.95 N/mm², compressive strength of 5.268 N/mm², flexural strength of 95.96 N/mm², and impact resistance of 0.20 J. Water absorption varied between 11.6% and 25%, depending on resin-to-fibre ratios. One-way ANOVA confirmed statistically significant differences among formulations (p = 0.005), validating the effect of fibre–resin composition. The optimal formulation (75% epoxy with balanced fibre reinforcement) achieved superior mechanical performance, establishing hybrid natural fibre composites as a promising eco-friendly alternative to conventional materials.

Abstract: Aim: This research evaluates the strength and stability of hemp, kenaf, and coir fiber reinforced composites produced by compression molding for industrial applications. Materials and Methods: Hemp, kenaf, and coir fibers are blended with a polymer matrix and compression molded. Group 1 (Traditional) This article illustrates the effective fabrication of hybrid fiber. Ultimately stabilized to a medium percentage of resin (75%). Group 2 (Composite) hemp, kenaf & coir blended fiber source more tensile, compressive strength and minimum water absorption rate and wear behavior. Result: The best were the kenaf composites, then hemp water resistance, and they all possessed good thermal stability. Compression molding assisted in enhancing fiber bonding. Conclusion: Compression molding improved the adhesion of fiber and matrix. Kenaf composite exhibited maximum strength, hemp exhibited maximum water resistance, and all of them exhibited good thermal stability.

Abstract: The PTO (Power-take-off) shaft is an essential rotatory component in agricultural tractor, used for transmitting power to shaft-driven implements such as rotary tiller, thresher, PTO driven pump, etc. During field operations, the PTO is subjected to uneven vibrational loads, which often lead to premature failure. These failures pose significant challenges pertinent to structural integrity, product quality as well as customer satisfaction. The current study conducts static and harmonic analysis to observe failure characteristics of conventional medium-carbon steel shaft under torsional loading. This study also explores the utilization of synthetic, natural, and hybrid-based fiber-based polymer composite to optimize overall weight and evaluate the impact of fiber orientation on stress and deformation behavior. The shaft was made up of unidirectional hemp and carbon-bamboo fiber reinforced epoxy, assuming isotropic characteristics for the fibers and polymer. A Representative Volume Element with a hexagonal array of circular fibers was developed using ANSYS Material Designer, maintaining a fiber volume fraction of 0.3 within the matrix. Laminated composites were then modeled using ANSYS Pre-Post Module with varying ply orientation to obtain an optimum configuration. Compared to the results of baseline steel shaft, Carbon fiber, Hemp fiber and Carbon-Bamboo fiber configurations demonstrated a mass reduction of 75.71%, 80% and 77.5%, respectively. These findings highlight the potential of composite PTO shaft as more economical, biodegradable, sustainable and light weight alternatives to steel in modern agricultural applications.

Abstract: Fused Deposition Modeling (FDM) is widely used in additive manufacturing. The main limitations of 3-Dimentisonal (3D) printing are the expansive cost of the material and its low strength as compared to the traditional molding process. The supported material was more expensive because of the extrusion process. The high surface roughness in the nature of 3D printed objects is the principal reason for mechanical property weakness. To eliminate such problems, a pellet-based 3D printer coupled with the layup fiber technique was introduced in this preliminary study. The obtained result indicated that the sample produced by the pellet-based printer had the highest mechanical strength in the machine direction. A reduction in tensile strength was found at another raster angle. After considering the differences between carbon fiber (CF) formats, it was found that chopped fiber was ineffective in terms of printed strength. At the same time, the layup fabric type and continuous fiber could promote better mechanical properties. When analyzing the ratio of maximum strength/fiber weight, it should be noted that continuous fiber presented the highest reinforced efficiency.

Abstract: The study used KH560 coupling agent to modify chopped glass fibers for reinforcing glass fiber/epoxy resin composites. As the glass fiber mass fraction increased, tensile, bending, and impact strength initially rose and then declined. Optimal mechanical reinforcement occurred at a 10% fiber mass fraction. SEM analysis revealed a well-integrated interface between glass fibers and the resin matrix, facilitating stress transfer and crack resistance. However, excessive fiber content led to diminished mechanical properties due to poor dispersion. Short-term UV aging significantly altered the composite's color, attributed to UV-induced photooxidation, though glass fibers' chemical stability mitigated deeper oxidation. Water exposure induced resin hydrolysis over time, further reducing mechanical properties. This research provides foundational insights for developing high-performance glass fiber reinforced epoxy resins as alternatives to metal power fittings.

Abstract: Methods of laser treatment and oxygen plasma treatment for the anti-reflective coatings on the basis of composite materials filled by epoxy polymer with multi-walled carbon nanotubes are demonstrated. The influence of structuring the surface of composite materials by different methods on the reflectivity in the UV, visible, near and middle IR wavelength ranges has been investigated. The possibility of creating composite structures with low reflectance in the range of 0.2 - 25 µm, corresponding to the requirements for anti-reflection coatings of optical and optoelectronic systems of spacecraft and ground-based systems, has been demonstrated.

Abstract: Almost no product is made today without the use of composite materials, which have demonstrated their value over time in a variety of applications. Examples include household products, automobiles, oil and gas stations and spacecraft. Instead of using timber, leaves will be used to create a solid material. The goal of this study is to identify the distinguishing features of composite materials made from dates palm waste, as well as the overall effects on the properties when changing the mixture's proportions and the amount to which those materials are vulnerable to outside influences. It also aims to identify the best material that can be produced and used in home furnishings, manufacturing, architectural design, practical applications, and other science-related fields. This project will address the use of natural fibers from dates palm waste and some other materials to convert them into a strong, lightweight, low-cost composite material to replace wood, aluminum, synthetic fibers, and other materials in industries and uses. It will also explore the manufacturing processes, testing methods, and the outcomes of comparing it with other materials. The UHU (adhesive) matrix has the lowest hardness value compared to others. Structure tests show composites' internal composition; it plays an important role in understanding the properties of composites. The water absorption test demonstrates the duration required for composites to become saturated with water, with optimal results falling within the range of 13 to 24 hours for saturation.