Reinforced Polymer Composites Research Articles

Tensile strength study of mensiang (scirpuss grossus) fibre composites with unsaturated polyester resin matrix

The mensiang (scirpuss grossus) is a plant that grows on moist and watery land. Mensiang plants are commonly used by the society to produce mats or bags that have a strong and durable texture. This mensiang plant has fibres that can be used as reinforcement in polymer composites as a substitute for synthetic fibres. In composite manufacturing, one of the important factors in determining strength is the fraction between fibre and matrix. This study was conducted to determine the effect of different volume fractions of composites on the tensile strength of mensiang fibre reinforcement. Extraction of fibre from the stem of the mensiang plant was done manually by combing, so that the fibre was obtained. The fibres were then naturally dried by the sun for 2-3 days. The composite manufacturing process was carried out by using the hand lay-up method. Specimens and tensile testing procedures refer to the ASTM D638 standard. Several specimens were made by varying the fibre and matrix fractions. The test results showed that the 12.5% fibre volume fraction had the highest tensile strength. In this study there was no chemical treatment on the fibres before the lamination process, thus, this can be suggested for future researchers to study on the effect of chemical treatment on mensiang fibres on fibre bonding with the matrix.

Investigation of natural cellulosic fibers from banana for potential reinforcement in polymer composites

Investigation of natural cellulosic fibers from banana for potential reinforcement in polymer composites

A comprehensive study of ultrasonic detection and damage quantification of barely visible impact damages in a carbon fiber reinforced polymer composite material

AbstractThis work investigates detection and evaluation of barely visible impact damage (BVID) on a carbon fiber reinforced polymer composite using non‐destructive evaluation. Specifically, this paper presents a novel method to analyze full waveform from ultrasonic data captured from a new field portable inspection station. Forty‐eight samples are impacted between 8 and 16 J representing a spectrum of surface damage below the visual threshold to barely visible surface damage. The samples are conditioned at cold and dry (5°C and 10%RH) to hot and wet (50°C and 90%RH) environmental conditions prior to inspection. Data collection for ultrasonic inspection is performed on a novel portable inspection system outside of an immersion tank, and the captured full waveform data is analyzed. The waveforms are analyzed using a new automated analysis approach presented in the current manuscript, and the effective diameter of the subsurface damage as a function of depth is extracted from the data set. The extracted three‐dimensional damage zone from the analysis of the ultrasound data shows damage increasing from the surface that is at or below the visual inspection threshold to a circular like damage zone with an effective diameter subsurface that is more than 20 mm. These damage zones are compared to the analyzed μCT data sets, and the average error is nominally 1 mm in characterizing the effective diameter at any depth. There is little correlation between the error and the impact energy or the environmental conditions studied, with the error ranging from 4% to 6% over the samples investigated.Highlights Out of immersion tank, field‐portable ultrasound inspection station, to detect BVID. Automated procedure to characterize three dimensionally the damage from a barely visible impact damage event. Sensitivity to environmental conditioning is investigated for its impact on inspections. Results validated with x‐ray CT with a typical accuracy of 1.32 mm.

Enhancing thermo-mechanical properties of additively manufactured PLA using eggshell microparticle fillers

Polylactic acid (PLA) is a widely studied polymer for potential biomedical applications and is one of the most commonly used polymers for additive manufacturing or 3D printing. Additive manufacturing (AM) technology is a fast-rising method of fabrication of polymer parts compared to other traditional fabrication techniques. In recent years, natural plant-based and animal-based fibers have shown immense potential to be used as fillers or reinforcements for polymer composites. In this study, chicken eggshell particles (ESP) have been used as inorganic calcium carbonate fillers to enhance PLA's mechanical properties. Four different concentrations (0 wt%, 1 wt%, 3 wt%, and 5 wt%) of PLA/ESP composite filaments have been extruded using a single screw extruder. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses were used to determine the chemical composition of eggshell powder, showing peaks matching with that of calcium carbonate (CaCO3). Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis show the effect of the filler on the PLA composite's thermal stability, indicating that pristine PLA has the highest melting temperature of 152 °C while the 5 wt% has the lowest melting temperature of 147 °C. The addition of eggshell particles slightly enhanced the compressive strength and dynamical mechanical properties of the PLA/ESP composites. The eggshell powders enhanced the dynamic mechanical property of PLA, with the 3 wt% concentration having the highest storage modulus at room temperature, with 5.2 % and 3.6 % increase for the filament and 3D printed samples respectively. Finally, the eggshell particles did not have much effect on the tensile and flexural strength of the composite, however, it enhanced the compressive strength of PLA with the 5 wt% sample having an average strength of 66.50 MPa and modulus of 2.27 GPa, respectively.

Evaluation of Static Behavior in Glass Fiber Reinforced Polymer Composites Cured with Hot Air and Infrared Radiation

Evaluation of Static Behavior in Glass Fiber Reinforced Polymer Composites Cured with Hot Air and Infrared Radiation

Physical and Mechanical Properties of Abaca Fiber Reinforced Polymer Composites for Sustainable Structural Application

This study evaluates the physical and mechanical properties of Abaca Fiber Reinforced Polymer (AbFRP) laminates for sustainable structural application. The research examines the impact of alkali treatment on the weight and diameter of the abaca fibers, as well as the tensile strength of both individual fibers and AbFRP laminates. The results indicate that the application of 0.5 wt% NaOH treatment reduced the weight and diameter of abaca fibers by 5.7% and 4.2%, respectively. Alkali treatment enhanced the tensile strength of single fibers, increasing it from 977.8 MPa to 1978.6 MPa, while the tensile strength of AbFRP laminates decreased from 78.1 MPa to 67.3 MPa. In terms of elastic modulus, the untreated and treated AbFRP laminates exhibited values of 14.9 GPa and 18.5 GPa, respectively. These findings demonstrate that AbFRP laminates possess notable mechanical characteristics, making them suitable for implementation for structural application.

Development and validation of modified constitutive model for carbon fiber reinforced polymer composites under impact loading

Development and validation of modified constitutive model for carbon fiber reinforced polymer composites under impact loading

Environmental Impact Assessment of Natural Vs Synthetic Fiber Reinforcement in Polymer Composites

Environmental Impact Assessment of Natural Vs Synthetic Fiber Reinforcement in Polymer Composites

Optimization of Fiber-Polymer Ratios for Enhanced Mechanical Properties in 3D-Printed Composites

The ratio of fiber to polymer is significant for improving the mechanical properties of fibrous polymers that are used for 3D printers’ applications in aerospace, automobile and Biomedical industries. This research on the behavior of fiber reinforced polymer composite material compares the impact of different fiber content on tensile strength, flexural strength, and impact resistance of 3D printed fiber reinforced polymer composites. From a range of fiber contents of 10%, 20%, and 30%, efficiency rises progressively with increasing fiber ratios, with the composite’s maximum tensile strength and flexural strength reached 60 and 55 MPa, respectively at the 30% fiber ratio. Nevertheless, if a structure exceeds the maximum of averaged values, one can meet more severe problems that have been described as brittleness and limited versatility in this study, which means that an optimal use of composites should imply a subtle balance between these parameters. Fiber-matrix adhesion is also a significant factor discussed in the study, which is a key parameter that defines the ultimate strength and life of the developed composites. These results do not only contribute to the knowledge of using 3D-printed composite materials but also provides benefits for proposing specific ideas in industries which attempt to introduce lightweight and high strength parts in their production lines. Some areas for further investigation are the effect of using other fiber orientation and the use of the hybrid fiber-polymer composites to achieve better mechanical properties and overcome problems arising from high fiber content. More specifically, this work helps to enrich the existing knowledge on the nutritional values of fibers and polymers with the aim of achieving optimal fiber-polymer ratios for enhancing the technique of three-dimensional printed composites

Experimental Evaluation of Thermal Conductivity in Glass Fiber Reinforced Polymer Composites for Aerospace Applications

Abstract: This paper aims to study the thermal conductivity properties of GFRP composites and their prospect in aerospace sectors. GFRP composites are gradually becoming the material of choice in aerospace, given the properties of low density, high strength, and high durability. However, it is critical to comprehend their thermal properties for efficiency in habitats characteristic of aeronautical environments. The work will seek to assess and quantify the thermal conductivity of the GFRP composites and establish the influence of fiber orientation, volume fraction and temperature in the thermal properties of the composites. Composite samples were prepared from E-glass and epoxy-amine prepreg’s with controlled layup and post curing. Some important measures in this work were thermal conductivity, which was tested by a laser flash method, and depend on conditions, offering valid information. In general, findings show that fiber orientation plays a major role in determining the thermal conductivity of the samples examined, where the highest conductivity is recorded on the samples where the fiber orientation is parallel to the direction of heat transfer. Higher fiber volume fraction was also found to improve thermal conductivity. Moreover, the temperature dependence analysis showed a fly increase of thermal conductivity at high temperatures that suggests that the material is capable of handling temperatures stress. The results indicate that GFRP composites have the right thermal characteristic appropriate for aerospace application, especially where thermal management is crucial for a particular part. Thus, more research is advised that particularly emphasizes the use of different types of fiber, various types of polymer matrices as well as different hybrid composites suited for high stress conditions. This research provides important information concerning the application of GFRP composites in the aerospace sector, including the ongoing development of lightweight, insulating materials suitable for this sector.

Investigation of physico-mechanical properties of Mimosa pudica micro-fibrils as an effective reinforcement in polymer composite

Investigation of physico-mechanical properties of <i>Mimosa pudica</i> micro-fibrils as an effective reinforcement in polymer composite

Enhancing the mechanical properties of flax fiber-reinforced epoxy composites through cellulose nanofiber incorporation

Cellulose nanofibers (CNFs) have attracted significant attention as effective reinforcements for polymer composites because of their outstanding mechanical and structural properties. This study explored the incorporation of CNFs into flax fiber reinforced epoxy composites to enhance their overall performance. To overcome the challenges of CNFs dispersion, an innovative approach was developed in which CNFs were preloaded onto flax fabrics before resin infusion using vacuum assisted resin transfer molding (VARTM) method. The morphological, mechanical, structural and thermal properties of the composites were comprehensively evaluated for various CNFs loadings (0.1, 0.3, and 0.5 wt%). Remarkably, a 0.3 wt% CNFs loading was found to significantly optimize the composite's Young's modulus, achieving a notable improvement of 204.02 %. This study underscores the potential of CNFs enhanced flax fabric composites for developing high-performance sustainable materials suitable for wide range of technical applications.

Characterization and modelling of the microstructural and mechanical properties of additively manufactured continuous fiber polymer composites

The additive manufacturing of continuous fiber reinforced polymer composites is a technology showing great potential for the production of end-use functional and structural components. The reasons for its still limited use are primarily related to an insufficient knowledge of the mechanical behavior of these composites, especially when considering the features that distinguish the printed components from conventional composite parts. Among these peculiar features, their bead-based architecture has been experimentally and analytically investigated in this study. Following an analysis of the process-morphology correlation, carbon fiber (CF)/polyamide 12 (PA12) specimens were tested to characterize the in-plane quasi-static material properties. Then, a modelling framework has been proposed for assessing the composite elastic properties and average bead stresses. This framework holds the potential to scale up to a structural level, accommodating various fiber trajectories.

Fabrication and property evaluation of waste glass dust filled epoxy‐hemp and epoxy‐flax hybrid composites

AbstractGlass dust particles, generated in glass cutting industries as a process waste possess health risk and serious environmental issues. This paper essentially reports on exploring the possibility of using this waste glass dust as particulate filler in two different natural fibers (hemp/flax) reinforced polymer composites. Such composites are prepared by hand lay‐up route, varying weight percentages of waste glass dust from 0 to 20. The physical and mechanical characterizations are evaluated experimentally. X‐ray diffractogram analysis reveals the degree of crystallinity of the composites and the phases present in the raw filler. With the incorporation of waste glass dust, the flexural strength, inter‐laminar shear stress and micro‐hardness of the composites are improved up to about 52 %, 44 % and 20 % respectively. On the contrary, tensile and impact strengths tend to decrease about 32 % and 17 % with filler content. Using scanning electron microscopy, the possible mechanisms such as fiber‐matrix de‐bonding, fiber‐pullout, matrix crack and rupture etc. are identified for failures of the composites under tensile, flexural and impact loadings. With low crystallinity and fairly good mechanical properties, these hybrid composites can have potential use in thermal insulations and low‐load engineering applications.

Effect of hygrothermal ageing on the mechanical properties of glass fiber reinforced polymer composite: Experimental and numerical approaches

This paper studied the effect of hygrothermal ageing on the mechanical performance of glass fiber-reinforced polymer composites (GFRPCs), a crucial material for marine applications due to its lightweight and superior resistance to environmental chemicals. However, prolonged exposure to moisture and temperature can degrade its properties, impacting structural integrity. The influence of moisture diffusion in GFRP composite laminates was evaluated by accelerated ageing tests, which involved submerging the composite laminate in seawater at 75°C until it reached full saturation. The composite laminates were fabricated with weight fractions of glass fiber reinforcements 55 %, 60 %, and 65 %. After two months of submersion, mechanical characteristics, namely tensile strength, modulus of elasticity, and interlaminar shear strength (ILSS) were investigated. A computational model was developed using COMSOL Multiphysics to analyse the coupled interfaces of moisture diffusion and heat. The failure mechanism of the GFRP composites was analysed using a scanning electron microscope (SEM). After two months of submersion, the moisture uptake data for the tension test samples showed a maximum saturation of 3.45 % for the 55 % fiber weight fraction, leading to a reduction in tensile strength from 269 MPa to 171 MPa and in modulus of elasticity from 24 GPa to 21 GPa. For the ILSS test samples, the maximum moisture saturation was 2.95 % for the 55 % fiber weight fraction, with a corresponding decrease in ILSS from 24 MPa to 21 MPa. However, increasing the glass fiber weight fraction from 55 % to 65 % resulted in improved tensile strength, modulus of elasticity, and ILSS in both as-manufactured and aged samples. The results of simulations and experiments showed that hygrothermal ageing causes the fiber surface to debond and causes matrix cracking, which in turn creates an uneven internal stress field.

Synergistic effect of alkali treatment and graphene filler on the mechanical characteristics of nettle fiber reinforced polymer composite

This study examines the synergistic effects of alkali treatment and the addition of graphene fillers to nettle fiber-reinforced polymer (NFRP) composites. NFRP composites were fabricated using NaOH-treated nettle fibers at concentrations of 3%, 5%, and 7%. Gr-NFRP composites were produced by varying the graphene content (1wt%, 2wt%, and 3wt%) in the epoxy resin that impregnated 5% NaOH-treated nettle fibers. The composites were prepared using a hand layup combined with a compression molding technique. A comprehensive analysis of the physical, mechanical, and wear properties of the treated NFRP composites was performed. FTIR analysis confirmed the effect of alkali surface treatment on the nettle fibers, whereas SEM was employed to examine the morphology of the fractured specimens. The experimental results revealed that a 5% NaOH solution was the optimal concentration for improving the characteristics of nettle fibers within the polymer composite. Moreover, the inclusion of 2wt% graphene noticeably enhanced the mechanical properties of the NFRP composites, resulting in increases of 21%, 17%, 65%, and 10% in the tensile strength, flexural strength, impact strength, and Shore D hardness, respectively. The wear resistance improved by 38%, and the water absorption decreased by 32%. SEM images revealed that a balanced contribution between fiber breakage and pullout was the primary failure mechanism in the Gr-NFRP composites. The NFRP composite containing 2wt% graphene demonstrated significant improvements in both mechanical and wear properties, along with reduced water absorption, making it a highly promising material for structural applications.

Shape parameter of Weibull size statistics is a potential indicator of filler geometry in SiO2 reinforced polymer composites

In a previous study [Physica A, 625 (2023), 129026], a relationship between the filler size distribution and the filler geometry of SiO2 particle reinforced polymer composites has been reported. It has been experimentally demonstrated that the size of hollow and solid SiO2 particles disperse in polymer matrix follows Weibull statistics with shape parameter at 2 and 3, respectively. This mechanism has not yet been verified in the one-dimensional (1D) case. In this paper, we study the length distribution of glass fibers in polymer composites. Our results show that the previous theory still holds for the 1D case. Thus, shape parameter of Weibull size statistics could be a potential indicator of filler geometry in SiO2 reinforced polymer composites. This interesting mechanism can be explained by the scaling nature behind the Weibull statistics. Our study has thus shed new light on the evolution of filler geometry during the fabrication process of polymer composites, and should be useful for the related fields.

Effects of Absorption on the Tribological Properties of Carbon Fiber Reinforced Polyamide-6 Composites Manufactured by Fused Deposition Modeling

Abstract The present work studied the water absorption behavior of polymeric composite materials fabricated using 3D printing technology, as well as its effect on their tribological properties. Polyamide-6 was selected as the base matrix material. Short and continuous carbon fibers are used as the reinforced material. The results showed that the moisture absorption would impair the mechanical properties of polymer matrix and interface bonding between the fiber and the matrix. As a result, the tensile strength of the fiber reinforced polymer composites (FRPCs) decreases with water absorption. Nevertheless, the effects of moisture absorption on the wear properties of FRPCs are more complicated, which are depending on the fiber length and sliding conditions. With the short fiber reinforcements, moisture absorption deteriorated the wear resistance under all the testing conditions. With the increase of moisture level, more severe fiber damage/removal was observed, associated with the higher wear loss. With a relative high volume fracture of continuous carbon fiber (∼35 vol%), however, the wear resistance of the FRPC increased with moisture level, especially under a relatively low load. Based on microscopic observations, it was proposed that water inside FRPC specimens is able to provide the lubricating and cleaning effects, which contribute to a lower friction and smooth worn surfaces. The work provides new insights into designing and selecting printed polymer materials, subjected to different loading conditions.

Non-Circular Cross-Section Fibres for Composite Reinforcement—A Review with a Focus on Flat Glass Fibres

Glass fibre reinforcements form the backbone of the composites industry. Today, glass fibre products account for more than 95% of the fibre reinforcements used in the composites industry. Since the first commercialisation of glass fibres for composite reinforcement in the 1930s, the cross-sectional shape of glass fibres has remained exclusively circular. However, many of the other types of fibre reinforcement have a non-circular cross section (NCCS). This paper reviews the available knowledge on the production of NCCS glass fibres and some of the possibilities that such fibres offer to enhance the performance of glass reinforced polymer composites. The three parts of the review focus on early research work on different shapes of glass fibre, the developments leading to industrial-level production of NCCS glass fibres, and the more recent data available on the influence of the available commercially produced NCCS flat glass fibres on composite performance. It Is concluded that the continued development of NCCS glass fibres may offer interesting potential to generate composites with increased performance and may also enable further tailoring of composite performance to enable new applications to be developed.

Investigation of cutting forces of glass sphere reinforced polymer composites

AbstractIn this study, the effects of reinforcement ratio, drill bit material, and drilling process parameters on the cutting forces generated during the drilling of glass sphere‐reinforced polypropylene composites were investigated experimentally. Test specimens were produced by conventional injection‐moulding of glass sphere reinforced polypropylene composite materials at 5 %, 10 % and 20 % wt. ratios. High speed steel, titanium‐coated high‐speed steel, and carbide drill bits with 4 mm diameter were preferred for drilling. In addition, the drilling process was carried out on a 3‐axis computer numeric control milling machine. Three different feed rates of 0.05 mm/rev, 0.10 mm/rev, and 0.15 mm/rev and cutting speeds of 12 m⋅min−1, 16 m⋅min−1, and 20 m⋅min−1 were determined for the drilling process. In addition, Taguchi experimental optimization method, analysis of variance and scanning electron microscopy were used to investigate the morphology of the drilled surface and the wear mechanisms occurring on the drill bit due to the drilling process. The test findings showed that the maximum torque value was 54.64 N⋅mm and the maximum thrust force was 100.43 N. The optimum test parameter for cutting forces was observed as C1D3FR1CS3. Drill parameter had an effect of 40.96 % on thrust force and 36.11 % on torque.