Performance Evaluation of Jute/Glass-Fiber-Reinforced Polybutylene Succinate (PBS) Hybrid Composites with Different Layering Configurations

Review and Assessment of Material, Method, and Predictive Modeling for Fiber-Reinforced Polymer (FRP) Partially Confined Concrete Columns

The repairing and strengthening of concrete structures using external and internal partial confinements are inevitable in the construction industry due to the new standards and rapid developments. The conventional materials and methods of confinement are unable to meet modern safety and functional standards. The fiber-reinforced polymer (FRP) enhances the strength and ductility of deteriorating and new concrete columns by reducing lateral confinement pressure and resistance against seismic shocks. The precise methods of partial confinement are inevitable for effective FRP-concrete bonding, durability, and cost-effectiveness under different loading conditions and to cope with external environmental factors. Predictive modeling and simulation techniques are pivotal for the optimization of confinement materials and methods by investigating the FRP-concrete novel confinement configurations, stress-strain responses, and failure modes. The novel materials and methods for concrete columns' partial confinement lack high compressive strength, ductility, chemical attack resistivity, and different fiber orientation impacts. This review provides an overview of recent confinement materials, novel methods, and advanced modeling and simulation techniques with a critical analysis of the research gaps for partial FRP confinement of concrete columns. The current challenges and future prospects are also presented.

Fatigue and Impact Properties of Kenaf/Glass-Reinforced Hybrid Pultruded Composites for Structural Applications

To address the weight, cost, and sustainability associated with fibreglass application in structural composites, plant fibres serve as an alternative to reduce and replace the usage of glass fibres. However, there remains a gap in the comprehensive research on plant fibre composites, particularly in their durability for viable structural applications. This research investigates the fatigue and impact properties of pultruded kenaf/glass-reinforced hybrid polyester composites tailored for structural applications. Utilising kenaf fibres in mat form, unidirectional E-glass fibre direct roving yarns, and unsaturated polyester resin as key constituents, pultruded kenaf/glass hybrid profiles were fabricated. The study reveals that pultruded WK/UG alternate specimens exhibit commendable fatigue properties (18,630 cycles at 60% ultimate tensile strength, UTS) and fracture energy (261.3 kJ/m2), showcasing promise for moderate load structural applications. Notably, the pultruded 3 WK/UG/3WK variant emerges as a viable contender for low-load structural tasks recorded satisfactory fatigue properties (10,730 cycles at 60% UTS) and fracture energy (167.09 kJ/m2). Fatigue failure modes indicate that the stress applied is evenly distributed. Ductile failures and delaminations during impact test can be attributed to damping and energy absorbing properties of kenaf fibres. Moreover, incorporating kenaf as a hybrid alternative demonstrates substantial reductions in cost (35.7-50%) and weight (9.6-19.1%). This research establishes a foundation for advancing sustainable and efficient structural materials and highlights the significant role of materials design in shaping the future of engineering applications.

Mechanical Performance of Glass/Epoxy Composites Loaded with Silane-Treated Aluminum Hydroxide Fillers

This study investigates the influence of silane-treated aluminum hydroxide on the mechanical performance of flame-retardant composites. These composites have potential applications for luggage bags, as a replacement for conventional plastics, offering more durability and lighter weight. Glass fabric was used as the reinforcement, while epoxy was used as the matrix material. To impart flame retardancy, aluminum hydroxide nanoparticles were used as fillers in different weight % age (5%, 10% and 15%). As these are inorganic particles and have compatibility issues with the matrix material, silane-coupling agents (Dynasylan® 6490 and Dynasylan Glymo) were used to treat these filler particles. Both the silane-coupling agents fraction used for treatment and the fillers fraction added to the composites were varied to determine the most optimum combination. The mechanical properties of the developed composites such as tensile, flexural, and short beam shear strength were investigated. The best results were exhibited by 10% aluminum hydroxide fillers treated with 1% (by weight) coupling agent (Dynasylan Glymo).

An Experimental Investigation into Mechanical and Thermal Properties of Hybrid Woven Rattan/Glass-Fiber-Reinforced Epoxy Composites

The investigation of hybrid, woven, natural fiber-reinforced polymer composites as a substitute reinforcement for fiber polymer composites has recently caught the interest of academics, industry, and researchers. Woven, natural fiber composites have been implemented in many different applications, including parts for automobiles, household items, flooring, aerospace, and ballistic materials. Therefore, this research seeks to establish the thermal and mechanical characteristics of composites made from rattan strips (RS) and glass fiber (GF)-reinforced epoxy resin (ER). Other than that, the impact of layering configurations with respect to the thermal and mechanical characteristics of the RS and GF will be determined. Hand lay-up and a hydraulic press machine produce hybrid, woven RS and GF laminates. The hybrid composite's mechanical properties will be investigated using impact, tensile, and flexural tests. The hybrid woven of the GF/RS/RS/RS/GF composite sequence demonstrated the highest mechanical properties in comparison to other sequences. The increase from one to three layers of RS in the core layer of GF hybrid composites enhanced the flexural, impact, and tensile properties. In addition, the hybridization of rattan and GF is more thermally stable, as recorded by the high decomposition temperature. As a finding of the research, the woven RS and GF hybrid is a potential material for automotive applications such as car bumpers, for example.

Recent Progress on Natural Fibers Mixed with CFRP and GFRP: Properties, Characteristics, and Failure Behaviour

Research on natural-fiber-reinforced polymer composite is continuously developing. Natural fibers from flora have received considerable attention from researchers because their use in biobased composites is safe and sustainable for the environment. Natural fibers that mixed with Carbon Fiber and or Glass Fiber are low-cost, lightweight, and biodegradable and have lower environmental influences than metal-based materials. This study highlights and comprehensively reviews the natural fibers utilized as reinforcements in polyester composites, including jute, bamboo, sisal, kenaf, flax, and banana. The properties of composite materials consisting of natural and synthetic fibers, such as tensile strength, flexural strength, fatigue, and hardness, are investigated in this study. This paper aims to summarize, classify, and collect studies related to the latest composite hybrid science consisting of natural and synthetic fibers and their applications. Furthermore, this paper includes but is not limited to preparation, mechanism, characterization, and evaluation of hybrid composite laminates in different methods and modes. In general, natural fiber composites produce a larger volume of composite, but their strength is weaker than GFRP/CFRP even with the same number of layers. The use of synthetic fibers combined with natural fibers can provide better strength of hybrid composite.

On the Numerical Modeling of Flax/PLA Bumper Beams

Significant progress has been made in green composites developing fully biodegradable composites made of microbially degradable polymers reinforced with natural fibers. However, an improvement in the development of numerical models to predict the damage of green composites is necessary to extend their use in industrial applications of structural responsibility. This paper is focused on developing a numerical model that can predict the failure modes of four types of bumper beams made of flax/PLA green composites with different cross sections. The predictions regarding energy absorption, contact force history, and extension of delamination were compared with experimental results to validate the FEM model, and both results revealed a good agreement. Finally, the FEM model was used to analyze the failure modes of the bumper beams as a function of the impact energy and cross-section roundness. The impact energy threshold defined as the maximum absorbed-energy capability of the beam match with the impact energy that produces delaminations extended through all the cross sections. Experimental and numerical results revealed that the threshold energy, where the maximum energy-absorption capability is reached, for Type A is over 60 J; for Type B and C is around 60 J; and for Type D is at 50 J. Since delamination is concentrated at the cross-section corners, the threshold energy decreases with the cross-section roundness because the higher the roundness ratio, the wider the delamination extension.

A Review on the Effect of Fabric Reinforcement on Strength Enhancement of Natural Fiber Composites

The main objective of this study is to examine the impact of reinforcements on the strength of natural fiber composites. Recent advancements in natural fiber composites have minimized the usage of man-made fibers, especially in the field of structural applications such as aircraft stiffeners and rotor blades. However, large variations in the strength and modulus of natural fiber degrade the properties of the composites and lower the safety level of the structures under dynamic load. Without compromising the safety of the composite structure, it is significant to enrich the strength and modulus of natural fiber reinforcement for real-time applications. The strength and durability of natural fiber can be enriched by reinforcing natural fiber. The reinforcement effect on natural fiber in their woven, braided, and knit forms enhances their structural properties. It improves the properties of natural fiber composites related to reinforcement with short and random-orientation fibers. The article also reviews the effect of the hybridization of natural fiber with cellulosic fiber, synthetic fiber, and intra-ply hybridization on its mechanical properties, dynamic mechanical properties, and free vibration characteristics, which are important for predicting the life and performance of natural fiber composites for weight-sensitive applications under dynamic load.

Non-Isothermal Crystallization of Titanium-Dioxide-Incorporated Rice Straw Fiber/Poly(butylene succinate) Biocomposites

In this work, titanium dioxide (TiO2)-incorporated rice straw fiber (RS)/poly(butylene succinate) (PBS) biocomposites were prepared by injection molding with different TiO2 powder loadings. The RS/PBS with 1 wt% TiO2 demonstrated the best mechanical properties, where the flexural strength and modulus increased by 30.34% and 28.39%, respectively, compared with RS/PBS. The non-isothermal crystallization of neat PBS, RS/PBS composites, and titanium-dioxide-incorporated RS/PBS composites was investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The non-isothermal crystallization data were analyzed using several theoretical models. The Avrami and Mo kinetic models described the non-isothermal crystallization behavior of neat PBS and the composites; however, the Ozawa model was inapplicable. The crystallization temperature (Tc), half-time of crystallization (t1/2), and kinetic parameters (FT) showed that the crystallizability followed the order: TiO2-incorporated RS/PBS composites > RS/PBS > PBS. The RS/PBS with 1 wt% TiO2 showed the best crystallization properties. The Friedman model was used to evaluate the effective activation energy of the non-isothermal crystallization of PBS and its composites. Rice straw fiber and TiO2 acted as nucleating agents for PBS. The XRD results showed that the addition of rice straw fiber and TiO2 did not substantially affect the crystal parameters of the PBS matrix. Overall, this study shows that RS and TiO2 can significantly improve the crystallization and mechanical properties of PBS composites.

Physical, Mechanical and Perforation Resistance of Natural-Synthetic Fiber Interply Laminate Hybrid Composites

Natural and synthetic fibres have emerged in high demand due to their excellent properties. Natural fibres have good mechanical properties and are less expensive, making them a viable substitute for synthetic fibers. Owing to certain drawbacks such as their inconsistent quality and hydrophilic nature, researchers focused on incorporating these two fibres as an alternative to improve the limitations of the single fibre. This review focused on the interply hybridisation of natural and synthetic fibres into composites. Natural fibres and their classifications are discussed. The physical and mechanical properties of these hybrid composites have also been included. A full discussion of the mechanical properties of natural/synthetic fibre hybrid composites such as tensile, flexural, impact, and perforation resistance, as well as their failure modes, is highlighted. Furthermore, the applications and future directions of hybrid composites have been described in details.