Search Results (185)

In recent times, fiber reinforced polymer composite materials have become more popular due to their remarkable features such as high specific strength, high stiffness and durability. Particularly, Carbon Fiber Reinforced Polymer (CFRP) composites are one of the most prominent materials used in the field of transportation and building engineering, replacing conventional materials due to their attractive properties as mentioned. In this work, a CFRP laminate is fabricated with carbon fiber mats and epoxy by a hand layup technique. Alumina (Al₂O₃) micro particles are used as a filler material, mixed with epoxy at different weight fractions of 0% to 4% during the fabrication of CFRP laminates. The important objective of the study is to investigate the influence of alumina micro particles on the mechanical performance of the laminates through characterization for various physical and mechanical properties. It is revealed from the results of study that the mass density of the laminates steadily increased with the quantity of alumina micro particles added and subsequently, the porosity of the laminates is reduced significantly. The SEM micrograph confirmed the constituents of the laminate and uniform distribution of Al₂O₃ micro particles with no significant agglomeration. The hardness of the CFRP laminates increased significantly for about 60% with an increase in weight % of Al₂O₃ from 0% to 4%, whereas the water gain % gradually drops from 0 to 2%, after which a substantial rise is observed for 3 to 4%. The improved interlocking due to the addition of filler material reduced the voids in the interfaces and thereby resist the absorption of water and in turn reduced the plasticity of the resin too. Tensile, flexural and inter-laminar shear strengths of the CFRP laminate were improved appreciably with the addition of alumina particles through extended grain boundary and enhanced interfacial bonding between the fibers, epoxy and alumina particles, except at 1 and 3 wt.% of Al₂O₃, which may be due to the pooling of alumina particles within the matrix. Inclusion of hard alumina particles resulted in a significant drop in impact strength due to appreciable reduction in softness of the core region of the laminates. Full article

To develop cement-based composite materials with exceptional impact resistance, this study investigates the impact resistance performance of steel fiber- and glass fiber-reinforced specimens, as well as steel fiber and glass fiber textile-reinforced specimens, through drop weight impact tests. The results showed that the impact resistance of specimens increases with the number of glass fiber textile layers, glass fiber volume fractions, and glass fiber lengths, with 36GF1.5SF1.0 exhibitinh ultra-high impact resistance with a failure impact energy of 114 kJ. Compared to the specimens reinforced with glass textiles, the specimens with glass fiber showed better impact resistance at the same volume fraction. The failure mode of unreinforced specimens is divided into several pieces, while fiber-reinforced specimens have local punching shear failure at the impact site, maintaining better integrity. An impact damage evolution equation and life prediction model based on a two-parameter Weibull distribution are developed. The research results will provide a reference for the selection of fibers for engineering applications. Full article

This study investigates the effect of fiber weight fraction on the tribomechanical behavior of basalt fiber-reinforced polymer (BFRP) composites under dry sliding conditions. Composite specimens with 50%, 65%, and 70% basalt fiber contents were manufactured and tested through tensile, flexural, and pin-on-disc tribological evaluations. Key tribological parameters, including the coefficient of friction (COF), specific wear rate (K), and contact temperature, were measured under various applied loads and sliding speeds. Statistical analysis was performed using a generalized linear model (GLM) to identify significant factors and their interactions. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses indicated that abrasive wear, matrix cracking, and fiber–matrix interfacial failure were the dominant wear mechanisms. The experimental results revealed that the fiber weight fraction had the most significant influence on COF (42.78%), while the sliding speed had the predominant effect on the specific wear rate (77.69%) and contact temperature (32.79%). These findings highlight the potential of BFRP composites for applications requiring enhanced wear resistance and mechanical stability under varying loading conditions. Full article

The additive manufacturing sector is rapidly developing, providing alternatives for mass production in the polymer composite industry. Due to the direction-dependent mechanical properties and high cost of fiber-reinforced polymeric materials, it is necessary to take advantage of alternative multi-materials and production technologies. In this study, a special geometric-shaped knitting technique was investigated using two different materials. The main material was polyamide 6 (PA6), and the inner or second material was PA6 with a 30 wt.% glass fiber addition by weight (PA6GF30). The special geometric shape, layer thickness, nozzle temperature, and post-heat treatment time were measured as process parameters in the production of the PA6/PA6GF30 composites with the fused deposition modeling (FDM) technique. The Taguchi design method and L9 fractional experiment were used in the experimental study. The mechanical behaviors of the PA6/PA6GF30 samples were obtained using tensile and impact tests. In addition, scanning electron microscopy (SEM) analyses were performed on the fracture lines of the PA6/PA6GF30 samples, and damage analyses were carried out in more detail. The experimental results were sorted using grey relational analysis (GRA). Moreover, the optimal experimental conditions and their related plots were obtained. As a result, the highest tensile strength of the PA6GF30 composite was 89.89 MPa with the addition of a special geometric shape. In addition, the maximum impact resistance value of the PA6/PA6GF30 composite was 83 kJ/m². Hence, the developed knitting method presented many advantages when using the FDM technique, and both were successfully used to produce the PA6/PA6GF30 composites. Full article

Laminate plate and shell structures with symmetric cross-ply configurations are widely used due to their high stiffness-to-weight ratio. However, conventional lamination theories rely on simplifying assumptions that may introduce inaccuracies. This study evaluates the predictive capability of such theories by integrating multiple micromechanics models with First-Order Shear Deformation Theory (FSDT), and comparing the results against voxel-based finite element modeling (VB-FEM), which serves as a high-fidelity numerical reference. A range of models—including Voigt–Reuss, Chamis, Halpin–Tsai, Bridging, and two iterative isotropized formulations—are assessed for unidirectional laminae with fiber volume fractions from 40% to 73%. Quantitative comparison reveals that while all models predict the longitudinal modulus accurately, significant deviations arise in predicting transverse and shear properties. The Bridging Model consistently yields the closest agreement with VB-FEM across all five elastic constants, maintaining accuracy even at high volume fractions where the modified Halpin–Tsai model begins to fail. Discrepancies in micromechanics-based lamina properties propagate to laminate-level stiffness predictions, highlighting the critical role of model selection. These findings establish VB-FEM as a valuable tool for validating analytical models and guide improved modeling strategies for laminated composite design. Full article

Diabetic nephropathy (DN) represents a severe microvascular complication of diabetes mellitus with limited therapeutic options, many of which are accompanied by considerable adverse effects. Opuntia ficus-indica (OFI) fruit, rich in vitamins, dietary fiber, and fatty acids, contains numerous bioactive compounds, including phytosterols, polysaccharides, and flavonoids that demonstrate significant potential in diabetes management. The flavonoid fraction derived from OFI fruit (OFI-F) has exhibited pronounced anti-inflammatory, antioxidant, and gut microbiota modulatory properties. However, the efficacy of OFI-F in ameliorating DN and its underlying mechanisms remain inadequately elucidated. This investigation examined the therapeutic potential of OFI-F in DN and explored its mechanistic pathways. Our findings demonstrate that OFI-F administration significantly attenuated renal injury and intestinal barrier dysfunction in the DN murine model. OFI-F intervention resulted in multiple beneficial outcomes in DN mice, including the mitigation of weight loss, reduction in hyperglycemia, decrease in renal coefficient index, and the attenuation of renal injury. An analysis of gut microbiota composition revealed that OFI-F administration favorably modulated the intestinal microbial community by enhancing the abundance of beneficial bacteria while concomitantly reducing populations of potentially pathogenic bacteria. Additionally, OFI-F treatment promoted the production of short-chain fatty acids (SCFAs), which contributed substantially to renoprotection and inflammatory resolution. Antibiotic intervention studies further confirmed the indispensable role of gut microbiota in mediating the renoprotective effects of OFI-F. In conclusion, this study provides compelling evidence supporting the therapeutic potential of OFI-F in DN management through the concurrent modulation of gut microbiota and renal function, offering a promising nutraceutical approach for alleviating renal injury in DN. Full article

Feeding accounts for approximately 70% of total costs in livestock production, underscoring the need for cost-effective and high-quality alternative feed sources. Almond hulls (AHs), a byproduct of the almond processing industry, represent a promising option due to their availability and potential nutritional value. Moreover, their inclusion in animal diets contributes to a reduction in environmental waste associated with their disposal. This study examined the effects of incorporating 4% sodium hydroxide (NaOH)-treated AHs into the diets of Assaf sheep (rams, ewes, and growing lambs) on feed utilization and animal performance. The experiment evaluated the chemical composition of AHs, nutrient digestibility, sexual behavior and semen quality in rams, milk composition in ewes, and the performance of growing lambs fed diets with increasing levels of inclusion of AHs. A total of 60 ewes and 21 rams were randomly assigned to one of three treatment groups, receiving diets containing 0%, 20%, or 40% AHs. NaOH treatment reduced the concentrations of organic matter and fiber fractions, while increasing the crude protein concentration of AHs (p < 0.01). Diets containing AHs did not affect nutrient digestibility (p > 0.05). Feeding a diet with 40% Na-OH-treated AHs significantly improved the daily weight gain (p = 0.002) of growing lambs up to 70 days after birth, and enhanced (p < 0.05) the libido, scrotal circumference, and semen quality of mature rams. In addition, ewes fed a diet containing 40% AHs showed (p < 0.05) improved fertility, prolificacy, and milk quality. NaOH-treated AHs are a cost-effective and sustainable feed ingredient that can improve reproductive performance and milk production, thereby increasing overall livestock productivity. The 40% inclusion level yielded the most favorable outcomes across all performance parameters evaluated in rams, ewes, and lambs. Full article

To address the issues of significant brittleness in self-compacting concrete (SCC), limited parameter ranges in existing steel fiber reinforcement studies, and incomplete performance evaluation systems, this study conducted mechanical performance tests on steel fiber-reinforced SCC (SFRSCC) with a wide range of volume fractions (1–3%) and multiple aspect ratios. A multi-indicator comprehensive evaluation model of compressive strength, flexural strength, and elastic modulus was established using an improved entropy-weighted TOPSIS method. Gray relational analysis was integrated to reveal nonlinear correlation patterns between fiber parameters (the volume fraction and aspect ratio) and mechanical responses. The experimental results demonstrated the following: (1) At a 3% fiber content, compressive and flexural strengths increased by 25.7% and 280%, respectively, compared to the control group; (2) the elastic modulus peaked at 2% fiber content, with excessive content (3%) causing an uneven fiber dispersion and diminishing performance gains; (3) short fibers (6 mm) achieved optimal compressive strength at 3% content and medium-length fibers (13 mm) significantly enhanced flexural strength, while long fibers (25 mm) maximized the elastic modulus at 2% content. The combined application of the improved entropy-weighted TOPSIS method and gray relational analysis identified that the high fiber content (3%) paired with medium-length fibers (13 mm) optimally balanced flexural strength and toughness, providing theoretical guidance for the application of SFRSCC in tensile- and crack-resistant engineering projects. Full article

Recycling of carbon fibers enables a sustainable feedstock for industrial applications of high-performance composite materials. This allows light weighting with recycled carbon fibers due to their superior mechanical properties while reducing the high embodied energy and cost of virgin carbon fiber composites. This study optimizes a pyrolysis cycle for fiber recovery of an aerospace-grade thermoset prepreg and a cleaning (oxidation) step to minimize fiber degradation and left-over resin residue, enabling dispersion and alignment of the recycled, discontinuous fibers in the Tailorable Universal Feedstock for Forming alignment process. The study balances the influence of the optimized thermal cycle (pyrolysis + oxidation step) on recycled carbon fiber strength retention with the ability to disperse at the filament level to create aligned, recycled carbon fiber composite samples with high fiber volume fraction. The optimized thermal cycle for efficient fiber recovery applied a pyrolysis step at 500 °C for 4 h in an inert gas environment and an additional oxidation step at the same temperature for 100 min. This resulted in ~20% strength degradation of the fiber compared to the virgin fiber. The processed recycled composite achieved 44% fiber volume fraction with full modulus translation (~128 GPa) compared to the virgin continuous composite with strength translation (~870 MPa), reaching ~50%. Full article

This study examined the effects of dietary crude protein (CP: 18%, 15%) and crude fat (EE: 8%, 4%) levels, and their interactions, on growth performance, nutrient digestibility, serum indices, and rectal fecal microbiota in sika deer fawns during early wintering. A two-month 2 × 2 factorial experiment was conducted using 32 healthy five-month-old male fawns randomly assigned to four groups: P18E8 (18% CP, 8% EE), P18E4 (18% CP, 4% EE), P15E8 (15% CP, 8% EE), and P15E4 (15% CP, 4% EE). The P18E4 group showed the highest total weight gain and average daily gain (p < 0.05), along with greater apparent digestibility of dry matter, crude protein, calcium, and fiber fractions (p < 0.05). Serum urea content was significantly lower in this group, indicating improved nitrogen utilization (p < 0.05). Dominant fecal microbiota at the phylum level across all groups included Firmicutes_A and Bacteroidota, with the P18E4 group showing a unique genus composition within Bacteroidota, known for enhancing fiber digestion. In summary, a diet with 18% CP and 4% EE optimized growth performance, nutrient digestibility, and gut microbiota composition, providing a strategy for improving the health and productivity of sika deer fawns during overwintering. Full article

The tribological performance of Glass Fiber Reinforced Polymer (GFRP) composites is essential for applications in automotive, aerospace, and industrial sectors. This study investigates the effect of fiber weight fraction ratio (wf.) (50%, 65%, and 70%), applied load, and sliding speed on the tribological behavior of twill-woven GFRP using a pin-on-disc tribometer. Experimental trials were carried out to assess the impact of control factors on the coefficient of friction, specific wear rate, and contact temperature. Statistical analyses based on generalized linear models (GLM) method or multi-factor ANOVA, identified the most significant factors and their contributions. Results indicate that sliding speed contributes the highest to COF (46.51%), while fiber wf. primarily influences wear rate (34.15%). The applied load was found to have the strongest impact on contact temperature (39.08%). Furthermore, SEM and EDS analyses reveal dominant wear mechanisms, including abrasive wear and transfer layer formation. This study introduces the novelty of using statistical modeling to optimize GFRP for high-performance tribological applications, providing a more precise and efficient approach to enhancing their properties. Full article

This study explores the combined effects of nanosilica (NS) and basalt fibers (BF) on the mechanical and microstructural properties of superabsorbent polymer (SAP)-modified concrete. NS (0–1.5% replaced by cement weight) and BF (0–1.2% by volume fraction) were incorporated to optimize compressive, flexural, and split-tensile strengths using response surface methodology. Digital Image Correlation (DIC) was employed to analyze failure mechanisms. Results show that while SAP alone reduced strength, the addition of NS and BF mitigated this loss through synergistic microstructure enhancement and crack-bridging reinforcement. The optimal mix (0.9% NS and 1.2% BF) increased compressive, flexural, and split-tensile strengths by 15.3%, 10.0%, and 14.0%, respectively. SEM analysis revealed that NS filled SAP-induced pores, while BF limited crack propagation, contributing to improved mechanical strength of SAP-modified concrete. This hybrid approach offers a promising solution for durable and sustainable concrete pavements. Full article

TiNbZr-(Ti,Nb)B composites were produced by vacuum arc melting; the weights of TiB₂ in the charge mixture were 0.7 wt. % (Alloy A) and 4.0 wt. % (Alloy B). In addition, unreinforced TiNbZr alloy specimens were fabricated without the addition of TiB₂. The microstructure of the TiNbZr-(Ti,Nb)B composites consisted of the TiNbZr β matrix and (Ti,Nb)B fibers. The (Ti,Nb)B fibers had a needle-like shape with an average diameter of ~0.4 and ~2.0 µm for Alloys A and B, respectively. The volume fraction of borides was found to be ~2.5 and ~12.4% for Alloys A and B, respectively. The presence of 12.4 vol.% of (Ti,Nb)B reduced the corrosion resistance of Alloy B in comparison with that of the TiNbZr alloy and Alloy A, which showed rather similar values of corrosion resistance. It was found that the addition of the TiB₂ to the TiNbZr alloy led to a decrease in the friction coefficient; when adding 0.7% TiB₂ to the alloy (Alloy A), the friction coefficient decreased from 1.15 to 1.13, and when the percentage of TiB₂ in the alloy increased to 4% (Alloy B), the friction coefficient decreased by ~2 times from 1.15 to 0.58. The full biocompatibility of TiNbZr-(Ti,Nb)B composites was demonstrated; no significant differences from the unreinforced state and alloy were found. Full article

The use of lightweight components in automobiles started a new chapter in the automotive sector due to the renewable energy and sustainability increasing the overall efficiency of vehicles. As vehicle weight is directly linked to energy consumption, reducing mass through advanced materials can significantly decrease energy usage and emissions over the vehicle’s lifetime. This present study aims to conduct a preliminary life cycle assessment (LCA) of a prototype battery pack manufactured using pultruded composite materials with a volume fraction of 50% glass fibers and a volume fraction of 50% nylon 6 (PA6) matrix by quantifying the CO₂ emissions and cumulative energy demand (CED) associated with each stage of the battery pack’s life cycle, encompassing production, usage, and end-of-life recycling. The results of the EuCia Eco Impact Calculator and from the literature reveal that the raw materials extraction and use phases are the most energy-intensive and contribute mainly to the environmental footprint of the battery pack. For a single battery pack for EV, the CED is 13,629.9 MJ, and the CO₂ eq emissions during production are 1323.9 kg. These results highlight the need for innovations in material sourcing and design strategies to mitigate these impacts. Moreover, the variations in recycling methods were assessed using a sensitivity analysis to understand how they affect the overall environmental impact of the system. Specifically, shifting from mechanical recycling to pyrolysis results in an increase of 4% to 19% of the total CO₂ emissions (kg CO₂). Future goals include building a laboratory-scale model based on the prototype described in this paper to compare the environmental impacts considering equal mechanical properties with alternatives currently used in the automotive industry, such as aluminum and steel alloys. Full article

With 3D printing technology, fiber-reinforced polymer composites can be printed with radical shapes and properties, resulting in varied mechanical performances. Their high strength, light weight, and corrosion resistance are already advantages that make them viable for physical civil infrastructure. It is important to understand these composites’ behavior when used in concrete, as their association can impact debonding failures and overall structural performance. In this study, the flexural behavior of two designs for 3D-printed glass fiber composites is investigated in both Portland cement concrete and polymer concrete and compared to conventional fiber-reinforced polymer composites manufactured using a wet layup method. Thermogravimetric analysis, volume fraction calculations, and tensile tests were performed to characterize the properties of the fiber-reinforced polymer composites. Flexural testing was conducted by a three-point bending setup, and post-failure analysis was performed using microscopic images. Compared to concretes with no FRP reinforcement, the incorporation of 3D-printed glass-fiber-reinforced polymer composites in cementitious concrete showed a 16.8% increase in load-carrying capacity, and incorporation in polymer concrete showed a 90% increase in flexural capacity. In addition, this study also provides key insights into the capabilities of polymer concrete to penetrate layers of at least 90 microns in 3D-printed composites, providing fiber bridging capabilities and better engagement resulting in improved bond strength that is reflected in mechanical performance. The polymer material has a much lower viscosity of 8 cps compared to the 40 cps viscosity of the cement slurry. This lower viscosity results in improved penetration, increasing contact surface area, with the reinforcement consequently improving bond strength. Overall, this work demonstrates that 3D-printed fiber-reinforced polymer composites are suitable for construction and may lead to the development of advanced concrete-based reinforced composites that can be 3D-printed with tailored mechanical properties and performance. Full article