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Highlights This study examines the mechanical properties of open‐hole unidirectional laminates by hybridizing jute and glass fabrics. Characterization involved microscopy, thickness variation, density measurements, tensile, and flexural tests. Numerical models were developed for each configuration, validated by experimental data, with a VUMAT subroutine implemented in ABAQUS/Explicit™ to simulate progressive damage using the 3D Hashin criteria. Results showed voids in the interphase regions of both jute‐based and hybrid laminates, indicating that jute fibers contribute to void formation. Thickness varied with the number of hybrid interfaces, with the glass laminate (G5) being thinnest, while jute and hybrid laminates (JGJGJ, JGGGJ and J5) were thicker. Density variation was influenced by the fiber types and their respective densities. Tensile tests revealed lower strength and modulus in jute laminates compared to glass. Open holes reduced tensile properties across laminates, except for G5. Numerical‐experimental tensile strength differences ranged from 0.5% to 6.1% (without hole) and 3.7% to 64.0% (with hole). Open‐hole laminates also showed reduced flexural strength but maintained a consistent flexural modulus. Numerical and experimental results for jute and hybrid laminates matched closely, with differences from 0.02% to 19.5%. Failure modes during tensile and flexural tests provided important insights into laminate behavior. Hybridization of jute and glass fibers led to void formation in interphase regions. Thickness variation in laminates influenced by the number of hybrid interfaces. Density variation primarily influenced by fiber types and their densities. Bi‐component jute laminates showed lower tensile properties compared to glass laminates. Open holes resulted in decreased tensile properties, except for G5‐H laminate. Failure modes during tensile testing provided valuable insights into laminate behavior. Open‐hole laminates exhibited reduced flexural strength with similar flexural modulus. [ABSTRACT FROM AUTHOR]

Highlights Fiber hybrid with bundle‐by‐bundle dispersion can achieve the high performance of composites, fully understand the hybrothermal resistance of hybrid composites is the key to prove the applications in engineering structures. In the present paper, the hygrothermal resistance performances of new type carbon and glass fiber reinforced epoxy based hybrid rod with bundle‐by‐bundle dispersion produced by pultrusion technology is investigated experimentally. The tests of water absorption and desorption, thermal and mechanical performances are performed to obtain the evolution rules of hygrothermal aging. As a result, the water absorption of hybrid rod confirms to the Fick's diffusion behavior, the serious relaxation of resin matrix and the interfacial debonding of fiber‐resin exposed at high temperature provide more diffusion space for water molecules. Long‐term hydrothermal aging results in the recoverable plasticization of resin matrix and irrecoverable interfacial debonding of fiber‐resin, which brings about the degradation of 6.7%–15.0% for short beam shear strength (SBSS) retention. In addition, the plasticization effect reduces the cross‐linking density of resin matrix, which leads to the degradation of 3.3%–15.6% for glass transition temperature (Tg) retention. The life prediction results show that degradation rate of SBSS is gradually slow down and reached to a stable retention of 85.5%. Relaxation of resin matrix and interfacial debonding accelerate the diffusion of water molecules. Plasticization and interfacial debonding lead to the degradation of short beam shear strength retention and glass transition temperature. Long‐term life prediction shows that short beam shear strength e retention is 85.5%. [ABSTRACT FROM AUTHOR]

This study investigates the residual tensile behaviour of hybrid Carbon Glass fibers reinforced thermoplastic PEEK laminates after they were exposed for 5 min to a hydrogen/oxygen flame. This flame results in a severe thermal aggression characterized by a wall temperature ranging from 900 to 1270 °C and with different heat fluxes (from 200 to 800 kW/m2). The thermally-induced damages were examined by means of microscopic observations and micro CT analyses. The results show that the mass loss linearly depends on the measured heat flux for a 5 min exposure. Depending on the fire testing conditions, the mechanical properties in tension (stiffness and strength) are totally degraded after exposure to the highest heat fluxes (600 and 800 kW/m2) but the retention of the tensile properties is moderate (about −35 to −60% decrease in strength and stiffness, respectively) after exposure to a 200 kW/m2 heat flux. The residual tensile properties of CG/PEEK laminates follow master curves representing the correlations between the mass loss and the changes in the tensile properties regardless the heat flux. These master curves provide a relevant design rule for composite parts to be used under critical service conditions (H 2 /O 2 flame exposure). • The influence of a H 2 /O 2 flame on the behaviour of composite materials was studied. • Wall temperature ranges from 900 to 1270 °C for heat fluxes from 200 to 800 kW/m2. • The mechanical properties are totally degraded after exposure to 600–800 kW/m2. • The changes in the tensile properties are correlated to the mass loss. • Master curves provide a criterion to design composite parts under H 2 /O 2 flame. [ABSTRACT FROM AUTHOR]

Sandwich panels with trapezoidal metal/glass fiber cores are increasingly popular due to their lightweight and energy-absorption properties. This study employs response surface methodology (RSM) and Box-Behnken design to investigate the effects of core angle, fiber orientation, and MCM-48 nanoparticles on the panels' energy absorption and peak force, developing regression models with high R2 values of 0.9027 and 0.9228, respectively. Experimental tests were conducted to validate these models, showing minimal deviation from predicted values. Results indicate that increasing the fiber orientation angle from 30° to 90° enhances energy absorption and peak force by 72.18 and 46.9%, respectively, and adding MCM-48 nanoparticles up to 0.25% weight improves energy absorption by 60.8%. A core angle of 52° balances energy absorption and peak force, while integrating a metal wire mesh within the panels significantly enhances energy absorption and reduces core brittleness. The optimal parameters for maximum energy absorption and minimum peak force include a core angle of 58°, fiber orientation of 73.5°, and no nanoparticles. These findings provide valuable insights into the design and optimization of sandwich panels for various applications. [ABSTRACT FROM AUTHOR]

In this study, a novel bionic periosteum (BP)‐bioactive glass fiber membrane (BGFM) is designed. The introduction of magnesium ion (Mg2+) and zinc ion (Zn2+) change the phase separation during the electrospinning (ES) jet stretching process. The fiber's pore structure transitions from connected to closed pores, resulting in a decrease in the rapid release of metal ions while also improving degradation via reducing filling quality. Additionally, the introduction of magnesium (Mg) and zinc (Zn) lead to the formation of negative charged tetrahedral units (MgO42− and ZnO42−) in the glass network. These units effectively trap positive charged metal ions, further inhibiting ion release. In vitro experiments reveal that the deigned bionic periosteum regulates the polarization of macrophages toward M2 type, thereby establishing a conducive immune environment for osteogenic differentiation. Bioinformatics analysis indicate that BP enhanced bone repair via the JAK‐STAT signaling pathway. The slow release of metal ions from the bionic periosteum can directly enhance osteogenic differentiation and vascularization, thereby accelerating bone regeneration. Finally, the bionic periosteum exhibits remarkable capabilities in angiogenesis and osteogenesis, demonstrating its potential for bone repair in a rat calvarial defect model. [ABSTRACT FROM AUTHOR]

Finfish aquaculture is one of the fastest-growing food production sectors in the world, and numerous infectious diseases are a constant challenge to the fish farming industry, causing decreased fish health and, consequently, economic losses. Specific and sensitive tools for pathogen detection are crucial for the surveillance of environmental samples to prevent the spread of fish pathogens in farms. Monitoring of waterborne pathogens through filtration of water and subsequent molecular detection of target-specific DNA or RNA sequence motifs is an animal-friendly method. This approach could reduce or even replace the sacrifice of fish for monitoring purposes in aquaculture and allow earlier implementation of disease control measures. Sampling methods might be a bottleneck, and there is a need for simple sampling methods that still ensure the best detection probability. In this study, we tested different filtration methods with spiked freshwater and seawater for a panel of fish pathogens to discern a suitable procedure that can be easily applied on-site by farm personnel without compromising detection probability. Specifically, we tested combinations of different filtration flow rates, lysis buffers, and filters for the detection of some of the pathogens relevant to the aquaculture industry. The results showed that a "sandwich" filtration method using two different filters and a flow rate of up to 4.0 L/min ensured good pathogen detection. The filters, consisting of a hydrophilic glass fibre filter with binder resin on the top and a hydrophilic mixed cellulose esters membrane at the bottom, achieved the best concentration and qPCR detection of both viral and bacterial fish pathogens. This up-and-coming tool allows the detection of very different fish pathogens during a single filtration step, and it can be combined with one single automated total nucleic acid extraction step for all the investigated pathogens, reducing both analysis costs and time. [ABSTRACT FROM AUTHOR]

Metallic glass fibers have high strength, poor plasticity and low Young's modulus. In this study, it was used as a reinforcement to prepare metallic glass fiber reinforced epoxy composites with different fiber volume contents (20%, 30%, 40%, and 50%). The effect of fiber volume contents on the tensile properties of the metallic glass fiber reinforced epoxy composites was studied by experiment and the finite element analysis method. The experiment and simulation results are in good agreement. The tensile strength and plasticity of the metallic glass fiber reinforced epoxy composites increase with the increase of fiber volume contents. When the fiber volume content is 40% or 50%, a sharply necking feature appeared on the fibers and exhibited improved plasticity, due to the formation of interacting and arresting events of shear bands occurring at the interface between the metallic glass fibers and the epoxy. In addition, the strain hardening due to plastic deformation of the metallic glass fibers further enhanced the tensile strength of the metallic glass fiber reinforced epoxy composites. This is a first step toward toughening the inherently brittle metallic glass fibers under tensile conditions. Highlights: A novel CoFeSiB metallic glass fiber reinforced epoxy resin compositeThe increase of fiber volume fraction improves the tensile strength and plasticity of fiber reinforced composites.The strain hardening due to plastic deformation of the metallic glass fibers further enhanced the tensile strength of the metallic glass fiber reinforced epoxy composites. [ABSTRACT FROM AUTHOR]

In this study, we investigate the relationship between structure and properties of fiber–matrix adhesion for material extrusion–based 3‐dimensional (3D) printed composites. We examine the influence of fiber length and fiber content on the tensile properties of glass, basalt, and carbon fiber–reinforced polylactic acid (PLA) composites. Short fiber–reinforced filaments were produced, then, simple micromechanical models were used to predict the in‐plane tensile properties. We found that interlayer tensile properties are strongly influenced by fiber–matrix adhesion. If adhesion is sufficient, the fibers and matrix deform together under tensile load. A second‐order relationship describes interlayer tensile strength in relation to fiber content between 5 and 25 w%, with a maximum at 15 w%, for carbon and basalt fiber–reinforced composites. If adhesion is weak, the crack propagates along the fiber–matrix interface, causing brittle fracture and low strength. This behavior was noted for the glass fiber composite, for which the calculated interface shear strength was the lowest (1.4 MPa). In this case, fiber content is inversely proportional to interlayer tensile strength. Our results show the role of fiber–matrix adhesion quality on tensile properties, which has a major impact on both the accuracy of predictions and the damage processes. Highlights: Critical fiber length determines accuracy of tensile property estimatesQuality of fiber–matrix adhesion governs interlayer damage processPoor adhesion causes brittle fracture and low strengthSecond‐order relationship of interlayer tensile strength and fiber contentLoss of interlayer tensile strength in composite due to fiber–matrix interface [ABSTRACT FROM AUTHOR]

This article aims to investigate the mechanical properties and substrate adhesion of the pull-off method in polymer mortars modified with styrene-butadiene resin polymer (SBR) containing glass powder and composite fiber-reinforced slag. Different mix designs were investigated with and without SBR, taking into account different amounts of glass powder and slag separately and in combination, along with the effect of glass, polypropylene, and steel fibers alone and in combination. The flexural performance and energy absorption of beams retrieved with these layers were also assessed. The results revealed significant differences and increases in the substrate adhesion of the restored modified polymer layers containing SBR compared to the polymer-free repair overlays. Furthermore, an improvement was observed in the adhesion performance of the repair overlay using a combination of slag and glass powder and the glass and polypropylene fiber composite. The highest adhesion was related to the modified polymer mortar design containing composite fibers of glass, polypropylene, and steel with 25% replacement of SBR polymer for 10% glass powder, 10% slag, and 5% slag with 5% glass powder. The adhesion was increased by about 3.74, 3.72, and 3.78 times compared to the repair overlay of the control design. Modified polymer mortars had a higher T 150 D toughness. Moreover, the energy absorption was significantly improved by the presence of SBR polymer. The highest toughness values were found in the beams restored with modified polymer mortars containing polypropylene, glass, and steel composite fibers with an increase of 48.51%-66.42% compared to the samples without polymer as a result of the pozzolans used in this mix. [ABSTRACT FROM AUTHOR]

The rampant dendrites growth caused by uncontrolled deposition of Zn2+ ions at Zn metal anode poses a significant obstacle to the practical applications of aqueous zinc‐ion batteries (ZIBs). Herein, an ultrathin (5 µm) aramid nanofiber (ANF) separator is reported to enhance the Zn anode stability and the ZIB energy density. Through systematic experimental studies and DFT simulations, it is demonstrated that the ANF separator with unique surface polarity can modify the solvation configuration, facilitate desolvation, and regulate the deposition orientation of Zn2+ ions. Consequently, the Zn anode with the ANF separator demonstrates an 85‐fold increase in running time beyond 850 h compared with the conventional glass fiber separator at 5 mA cm−2/2.5 mAh cm−2. Even under the harsh depth of discharge conditions of 50% and 80%, the Zn anodes still sustain extended cycling periods of over 475 and 200 h, respectively. As pairing this ANF separator with thin Zn anode and high‐areal‐capacity Mn2.5V10O24∙5.9H2O cathode in a low negative capacity/positive capacity ratio (2.64) full cell, superior gravimetric/volumetric energy density (129.2 Wh kg−1/142.5 Wh L−1) is achieved, far surpassing majority of the ZIB counterparts reported in the literature. This work offers a promising ultrathin separator for promoting the utilization of energy‐dense aqueous ZIBs. [ABSTRACT FROM AUTHOR]

Highlights Recently, thermosetting epoxy resin is expected to be substituted by thermoplastic featured from green circular economy. Poly(methyl methacrylate) (PMMA) has been well known as one promising thermoplastic resin, although its mechanical property needs to be further investigated. In this paper, the free radical polymerization of methyl methacrylate (MMA) was initiated by lauroyl peroxide/N,N‐dimethylaniline (LPO/DMA) and lauroyl peroxide/N,N‐dimethyl‐p‐toluidine (LPO/DMT) redox system at room temperature, respectively. The PMMA (n(MMA:LPO:DMA) = 200:1.2:1) exhibited excellent mechanical properties, and the tensile strength was 66.5 MPa, the bending strength was 118.0 MPa. The tensile strength increased to 78.9 MPa at −40°C, which suggested a promising application at low temperature. The resin was applied to fabricate continuous glass fiber reinforced PMMA (GF/PMMA) composites by vacuum‐assisted resin infusion. The 0° tensile strength and modulus were 1.17 and 43.7 GPa and 90° tensile strength and modulus were 48.3 MPa and 13.2 GPa, respectively. The mechanical properties of GF/PMMA composites are higher than GF/epoxy. Moreover, PMMA resin and glass fiber can be recycled from GF/PMMA composites by MMA as solvent, which is more energy‐efficient and environment‐friendly. This work is of great significance for preparing sustainable resin and composites. GF/PMMA composites were fabricated by vacuum perfusion. GF/PMMA composites showed higher mechanical properties than GF/epoxy. GF/PMMA composite was recycled with MMA and closed‐loop recovery was achieved. [ABSTRACT FROM AUTHOR]

Highlights Two‐phase hybrid modification has been used as an advanced method to improve the strength and toughness of composite. An interfacial modification strategy for simultaneous strengthening, toughening, and damage monitoring of glass fiber (GF)/epoxy composite is proposed by coating rigid multi‐walled carbon nanotubes (MWCNT) and flexible thermoplastic polyurethane (TPU) on the glass fiber surface. The fiber pull‐out and out‐of‐plane experiments were performed to investigate the interfacial modification effect of rigid/flexible hybrid modifier. The results show that the hybrid modifier with a MWCNT/TPU mass ratio of 3:1 (MT@GF‐3/epoxy composite) realizes the most significant enhancement. Specifically, in comparison to GF/epoxy composites, MT@GF‐3/epoxy composite has an increment of 36.52%, 60.96%, 29.56%, and 80.36% in interfacial shear strength (IFSS), transverse fiber bundle test (TFBT) strength, interlaminar shear strength (ILSS) and interlaminar fracture toughness (GIC), respectively, and a significant enhancement in impact resistance. The enhanced interfacial strength and toughness are attributed to the mechanical interlocking, deflection of cracks, and plastic stretching generated by MWCNT and TPU. Results show that the two modifiers interact in a mutually reinforcing way with regard to the strengthening/toughening effects. In addition, multiple mechanical tests confirm the MT@GF/epoxy composites have an excellent damage monitoring ability by recording the resistance change based on the MWCNT's conductive characteristics. This strategy for interfacial modification coating a rigid‐flexible MWCNT/TPU hybrid modifier would offer valuable guidance for improving the strength and toughness of glass fiber/epoxy composites, as well as monitoring and locating the damage. A rigid/flexible hybrid modifier is proposed for modifying the GF/EP composites. The modifier achieves the greatest enhancement at a 3:1 mass ratio of MWCNT/TPU. The mutual reinforcing mechanism between the rigid/flexible phases is analyzed. Damage monitoring is realized for the modified GF/EP composites. [ABSTRACT FROM AUTHOR]

Highlights A detailed investigation was employed on the manufacturing process of Glass Fiber (GF) reinforced poly‐L‐lactide (PLLA) composites (GFRP) during in‐situ PLLA polymerization using Resin Transfer Molding (RTM). The lower viscosity of lactide, in comparison to PLLA, led to a strong interaction between PLLA and GF as a result of improved penetration into the fiber matrix, resulting in a high conversion rate of 100% for GFRP and 91.9% for PLLA. GF incorporation into the composite material resulted in an improved crystallinity of 55.65% for GFRP, where PLLA showed crystallinity of 36.5%. A GFRP composite with exceptional mechanical properties, including 122.3 MPa tensile strength and 4.485 GPa modulus, was achieved. Both surface and bulk erosion were seen during the breakdown of these composites. These composites seem to be a viable substitute for metallic implants in biological applications. In situ, resin transfer molding of poly‐l‐lactide and GF composite. Higher volume fraction such as 40% w/v loading of GF into composites. 1% conversion of GFRP is achieved. GFRP shows the machinal strength of 122 MPa and harness of 4.2 GPa. Biocompatibility of GFRP composites in body stimulated conditions. [ABSTRACT FROM AUTHOR]

AbstractIn order to study the mechanical properties of seawater sea sand concrete and the durability damage law of seawater sea sand concrete under the action of seawater erosion, corresponding specimens were prepared and subjected to cube compressive strength, flexural strength, and dry-wet cycle tests by taking the volume dosage of glass fibers and polyvinyl alcohol fibers as variables. The test combined SEM scanning and EDS to analyze the microstructure of fiber-reinforced seawater sand concrete, and established a model based on the two-parameter Weibull probability distribution. The results show that the fiber has a significant effect on improving the mechanical properties and erosion resistance of seawater sand concrete. When the total volume content is 0.3% and the mixing ratio is 1:1, the improvement effect is the best. The maximum increase in cubic compressive strength was 24.2%; the maximum increase in flexural strength was 38.8%. After the specimens were subjected to wet and dry cycles for 360d, the maximum reduction in mass loss rate was 41.23%; the maximum reduction in strength loss rate was 27.55%. As observed from the microscopic images, the main disadvantage of SSC is that the salt crystallization and swelling matter produced by the erosion ions will weaken the bond between aggregate and mortar, resulting in defects in the interfacial transition zone (ITZ). Under the action of dry-wet cycles, the alternating dry-wet forces, the expansion pressure generated by expansive substances and the crystallization pressure generated by salt crystallization will change the microstructure, and therefore the damage of the specimen will deepen with the extension of erosion time. The microscopic images also show that the doping fibers can improve the internal integrity and compactness of the matrix, thus significantly improving the mechanical properties and durability of seawater sea sand concrete. In this test, a damage model was established based on the two-parameter Weibull distribution model, and the damage law between strength loss and dry-wet cycles was fitted, which provides a favorable basis to study the damage of seawater sea sand concrete under wet-dry cycling. [ABSTRACT FROM AUTHOR]

The commercialization of sodium batteries faces many challenges, one of which is the lack of suitable high-quality separators. Herein, we presented a novel natural silkworm cocoon-derived separator (SCS) obtained from the cocoon inner membrane after a simple degumming process. A Na||Na symmetric cell assembled with this separator can be stably cycled for over 400 h under test conditions of 0.5 mA cm−2–0.5 mAh cm−2. Moreover, the Na||SCS||Na3V2(PO4)3 full cell exhibits an initial capacity of 79.3 mAh g−1 at 10 C and a capacity retention of 93.6% after 1000 cycles, which far exceeded the 57.5 mAh g−1 and 42.1% of the full cell using a commercial glass fiber separator (GFS). The structural origin of this excellent electrochemical performance lies in the fact that cationic functional groups (such as amino groups) on silkworm proteins can de-solvate Na-ions by anchoring the ClO4− solvent sheath, thereby enhancing the transference number, transport kinetics and deposition/dissolution properties of Na-ions. In addition, the SCS has significantly better mechanical properties and thinness indexes than the commercial GFS, and, coupled with the advantages of being natural, cheap, non-polluting and degradable, it is expected to be used as a commercialized sodium battery separator material. [ABSTRACT FROM AUTHOR]

The injection molding process is one of the most widely used methods for polymer processing in mass production. Three critical factors in this process include the type of polymer, injection molding machines, and processing molds. Polypropylene (PP) is a widely used semi-crystalline polymer due to its favorable flow characteristics, including a high melt flow index and the absence of a need for a mold temperature controller. Additionally, PP exhibits good elongation and toughness, making it suitable for applications such as box hinges. However, its tensile strength is a limitation; thus, glass fiber is added to enhance this property. It is important to note that the incorporation of glass fiber increases the viscosity of PP. Multi-cavity molds are commonly employed to achieve cost-effective and efficient mass production. The filling challenges associated with geometrically balanced layouts are well documented in the literature. These issues arise due to the varying shear rates of the melt in the runner. High shear rate melts lead to high melt temperatures, which decrease melt viscosity and facilitate easier flow. Consequently, this results in an imbalanced filling phenomenon. This study examines the impact of runner size, gate size, polymer viscosity, and molding process on the filling imbalanced problem in multi-cavity injection molds. Tensile bar injection molding was performed using conventional injection molding (CIM) and microcellular injection molding (MIM) techniques. The tensile properties of the imbalanced multi-cavity molds were analyzed. Flow length within the cavity served as an indicator of the filling imbalance. Additionally, computer simulations were conducted to assess the shear rate's effect on the runner's melt temperature. The results indicated that small runner and gate sizes exacerbate the filling imbalance. Conversely, glass fiber-filled polymer composites also contribute to increased filling imbalance. However, foamed polymers can mitigate the filling imbalance phenomenon. [ABSTRACT FROM AUTHOR]

Bismuth (Bi) and Germanium (Ge) co‐doped silica glass and fiber, as advanced gain media with broadband near‐infrared (NIR) emission and amplification, have promise for extending communication bandwidth. However, efficiently modulating the NIR emissions of bismuth to cover the C+L communication bands remain a significant challenge. In the study, a high‐temperature and high‐pressure reduction treatment on Bi/Ge co‐doped silica glass is employed to tailor the coordination environment around bismuth active center. This method facilitated the creation of new bismuth NIR luminescence centers, resulting in the luminescence spectrum with a peak position at 1550 nm and a FWHM exceeding 350 nm. The changes in the bismuth coordination environment are elucidated using HRTEM, photoluminescence decay, temperature‐dependent emission, EXAFS and CW‐EPR. Furthermore, the feasibility of this method in Bi/Ge co‐doped silica fiber is validated, and obtained >5 dB amplification in the range of 1400–1700 nm. This coordination engineering method holds significant potential for widespread application in Bi/Ge co‐doped silica glass and optical fiber is believed. It presents a promising prospect for expanding communication bandwidth by effectively modulating the NIR emissions of bismuth to cover the S to U communication band. [ABSTRACT FROM AUTHOR]

Titanium dioxide-enriched phosphate glasses are esteemed for their applicability in the biomaterial area, yet the investigation into the influence of TiO 2 on the crystallization dynamics of glass melts and the spinnability of sodium-calcium-magnesium phosphate glasses remains unclear. To elucidate these effects, sodium-calcium-magnesium phosphate glasses with 0, 5, and 10 mol% of TiO 2 have been prepared using the melt-quenching method, and glass fibers were drawn from the correspondent glass melts. FTIR and Raman spectroscopy have disclosed that the introduction of TiO 2 induces a depolymerization in phosphate network, causing a transition from Q2 species to Q1 units, and reduction in both the theoretical network connectivity (NC theor) and the average chain length (n theor). Meanwhile, the interposition of TiO 2 also gives rise to the replacement of P–O–P linkages with P–O–Ti bonds, along with the formation of [TiO 5 ] groups. This structural transformation resulted in the increase in molar volume and the coefficient of thermal expansion (CTE), concurrently lowering the glass transition and softening points. Evidently, the TiO 2 -free glass exhibited crystallization across a temperature range spanning from its transition to the liquidus temperature. However, the introduction of TiO 2 and the subsequent formation of P–O–Ti bonds effectively inhibited crystallization, which is favorable for drawing glass fibers. Analyses of viscosity-temperature relationships using various rheological models suggested that TiO 2 raises fragility for all glasses, suggesting a more "open" structure in the glass melts, which can be supported by the increment in free volume. The m-D diagram failed to describe the enhancement in spinnability imparted from TiO 2. While, the quantitative fiber spinnability index (K fib) increases with higher TiO 2 content, as a successful indicative of an improved ability to form fibers. [ABSTRACT FROM AUTHOR]

Glass-based sealing materials exhibit significant potential for utilization in solid oxide fuel cells (SOFCs). We conducted a study on the impact of mullite fibers with varying particle sizes on glass composite sealing materials. We evaluated and discussed properties such as coefficient of thermal expansion (CTE), softening temperature (Ts), gastightness, interfacial compatibility, and flexural strength of the sealing materials with different ranges of fiber particle sizes. Our findings indicate that the three different particle sizes of mullite fiber-glass composite sealing materials met the required coefficients of thermal expansion, displayed good interfacial compatibility, and exhibited gastightness lower than 0.0016 sccm cm−1. Notably, the mullite fiber-reinforced sealing material that underwent ball-milling for 1 h outperformed the other two variants. It demonstrated fewer defects, a 57.1 % increase in flexural strength, and a 117.4 % higher maximum strain value. [ABSTRACT FROM AUTHOR]

Highlights In this study, the axial crushing response and energy‐absorbing mechanisms of circular composite tubes, which were reinforced by carbon fiber (C10) and carbon/glass hybrids (C3G4C3), were investigated experimentally and numerically. Both samples exhibited similar crushing responses comprising delamination and intralayer shear failure. The impact kinetic energy is primarily converted into frictional and composite damage energies. C3G4C3 had poorer crashworthiness with a mean crushing force and specific energy absorption of 313.3 kN and 58.0 kJ/kg, which are by 39.3% and 30.8% less, respectively, than those of C10. The influence of glass fiber reinforced polymers (GFRP) content (hybrid ratio) and stacking sequence on tubal crashworthiness was investigated numerically. For composite tubes with a hybrid ratio of 40%, the central distribution of GFRP (C3G4C3) achieved optimal energy absorption performance. Additionally, when GFRP layers were centralized stacked, a reduction of the hybrid ratio from 60% (G3C4G3) to 20% (GC8G) helped improve the crashworthiness of the hybrid tubes, where the mean crushing force increased by 23%. Impact responses of composite tubes reinforced by carbon fiber and carbon/glass hybrids were investigated experimentally and numerically. Carbon/glass hybrid tubes exhibited lower crashworthiness. The effects of stacking sequence and hybrid ratio on the energy absorption performance were studied. [ABSTRACT FROM AUTHOR]

Highlights Present study comprehensively explores the phenomenon of in‐plane fiber waviness in glass/epoxy fiber reinforced polymer (GFRP) composites. Utilizing a pioneering technique that employs a semi‐circular bar to induce controlled fiber waviness, coupled with image processing using OpenCV library in Python coding for precise measurement and analysis of in‐plane fiber waviness. This defect is commonly found in components fabricated with fiber‐reinforced composites. During the process of manufacturing fibers may deviate from their intended orientation due to process variables or resin flow dynamics. Understanding in‐plane fiber waviness is crucial due to its impact on mechanical properties of composites. It is essential for optimizing manufacturing processes and ensuring enhanced structural performance in diverse engineering applications through analysis of strength and failure mechanism. A novel study was conducted by introducing a circular cutout within the fiber waviness region to investigate the combined effect of multiple defects. The experimental tensile test reveals that as waviness ratio (WR) increases a significant decrease in its tensile strength and vice versa. The study incorporates scanning electron microscopy (SEM) image analysis to examine composite failure. By advancing the understanding of in‐plane fiber waviness and its implications, this research significantly contributes to ongoing efforts in composite design and optimization. Adopting a cutting‐edge method to create controlled fiber waviness that makes use of a semi‐circular bar. Image processing with Python code that makes use of the OpenCV package to precisely measure and analyze in‐plane fiber waviness. A new investigation was carried out to examine the combined effect of multiple flaws by creating a circular cutout within the fiber waviness zone. [ABSTRACT FROM AUTHOR]

(1) Background: The main aim of this study was to investigate the effects of different cements (Panavia V5, RelyX U200) and placement techniques (indirect ultrasonic vibration and manual method) on the bond strength of glass fiber posts in teeth with different post space preparation methods and to evaluate the failure types. (2) Methods: A total of 120 human upper central teeth were collected for the study. One week after root canal treatment, 10 mm long post space preparation was performed using post drills. Post spaces were irrigated in three different ways, namely NaOCl, NaOCl + EDTA solutions, and passive ultrasonic irrigation of NaOCl and EDTA solutions. Glass fiber posts were divided into two groups for resin cement systems, namely RelyX U200 (3M ESPE) or Panavia V5 (Kuraray Medical). Two different methods, namely the indirect ultrasonic vibration and the manual method, were applied for post placement. Then, 1.2 mm sections were taken from the middle and coronal regions of the inserted fiber posts for a push-out test. (3) Results: the Irrigation × Cement (p = 0.002), Cement × Section (p = 0.043) and Placement × Section (p = 0.049) pairwise interactions were statistically significant. (4) Conclusions: in our study, the effects of different post cavity preparations, different cement types, and different placement techniques on the bond strength of the fiber post were observed. [ABSTRACT FROM AUTHOR]

Although numerous investigations study the improvement of flame retardancy of epoxy resins using additives, maintaining the flame retardant (FRs) modes of action present in the resins upon transfer to composites is challenging. In this study, ammonium polyphosphate (APP) and inorganic silicate (InSi) are loaded at 10%, 30%, and 50% by weight, in a diglycidyl ether of bisphenol A (DGEBA) resin cured with dicyandiamide and transferred to bidirectional (BD) glass fiber (GF) composites. Although a 50% loading of the FRs impacts the curing kinetics of the resin system, the effect on the glass transition temperature of the resin system remains negligible compared to reactive FRs in the state of the art integrated into the resin's chemical structure. Increasing the FR content improved the heat release characteristics in both the resins and composites. However, the charring mode of action is completely suppressed in the formulation with 10% APP + InSi. A 30% concentration of the FRs restored the charring action in the composite and the GFs provide increased protective layer action upon transfer to the composites. This study highlights the importance of accounting for the changing dynamics related to processing and flame retardancy upon transferring FRs from resins to composites. [ABSTRACT FROM AUTHOR]

Polymer matrix composites are extensively used in numerous industrial and engineering applications, and utilization of these materials has been extended to different and novel areas where it is essential to study and improve their mechanical properties. In this paper, the hand layup technique is used to prepare composites from a vinyl ester resin matrix filled with 4 wt.% chopped glass fiber and different silicon nitride particle contents with concentrations of 1.5, 2, 2.5, 3, 3.5, and 4 wt.% are used to study erosive wear, flexural, compression, and hardness tests. The air-jet-type test rig is used to measure erosive wear rate under four factors: weight fraction of both glass fiber and silicon nitride particles, impingement angles 30°, 45°, 60°, and 90°, size sand particles 250, 450, 650, and 850 μm, and standoff distance 18, 20, 22, and 24 cm at constant 15 hours. MINITAB (L16) is utilized for erosive wear parameter analysis. It is observed that the specimens (vinyl ester–4% chopped glass fiber–4% silicon nitride) have better erosive resistance properties as compared to other specimens. Moreover, the addition of 4 wt.% silicon nitride particles in the vinyl ester resin filled with chopped glass fiber improved the values of flexural strength, compressive strength, and hardness shore D significantly. The signal-to-noise results showed that the 4% weight ratio of silicon nitride particles, 90° impingement angles, 250 μm sand size, and 22 cm standoff distance gave the best erosive resistance. The analysis of variance showed that specimens (A), size of sand particles (C), and standoff distance (D) are the most important factor affecting the erosive rate, while the angle (B) factor has less effect on the erosive rate. Also, the interaction plot for all control parameters showed an important effect on erosive wear. It is observed that the properties of vinyl ester resin have improved after being strengthened with chopped glass fibers and silicon nitride particles, which can proposed for specific applications such as sewage pipes, helicopter fan blades, and desert structures. [ABSTRACT FROM AUTHOR]

In this study, the post‐buckling damage behavior of cylindrical composite tubes was examined experimentally. The samples were reinforced with glass, carbon, and kevlar fibers to obtain glass‐reinforced fiber polymer (GRFP), carbon‐reinforced fiber polymer (CRFP), and Kevlar‐reinforced fiber polymer (KRFP) cylindrical tubes. The samples were produced using 4 stacking layers with filament winding technology. In producing all composite tubes, the outer diameter was kept constant at 17 mm, and two inner diameters of 12 and 13 mm, two wall thicknesses, 5 winding angles, and two lengths were used as parameters. The load was applied to the samples until completely damaged, and the maximum post‐buckling load values obtained were measured on the testing device. The effect of different reinforcement materials, winding angle, wall thickness, and length on the load‐carrying capacity was analyzed and it was understood that they had a significant effect. It was observed that the load‐carrying capacity of GFRP samples was the highest compared to the others, followed by CFRP and KFRP samples, respectively. In all samples, it was observed that a 0.5 mm wall thickness increase increased the load‐carrying capacity, while a 50 mm length increase decreased it. The energy absorption (EA) values of GFRP, CFRP, and KFRP samples were 46.99, 25.22, and 15.48 Joules, respectively. It was understood that the energy absorption of GFRP samples was 1.86 times better than CFRP and 3 times better than KFRP. Highlights: The samples were produced using the fiber winding method, which is one of the most common production methods in the manufacture of tubes.Three different polymer reinforcement materials were used in the production of the samples.The effects of polymer reinforcement material, winding angle, length, and wall thickness on the maximum post‐buckling load were investigated.Wall thickness was found to have a significant effect on the maximum post‐buckling load.It was observed that GFRP samples had the highest energy absorption feature. [ABSTRACT FROM AUTHOR]

This research aimed to understand how the incorporation of nanocarbon powder (NCP) influences the crashworthiness performance of glass fiber‐reinforced epoxy (GFRE) tubular components, potentially offering insights into improving the safety and resilience of structures or vehicles. Consequently, the crashworthiness behaviors of circular tubes made of GFRE with varying amounts of NCP was studied. Utilizing wet‐wrapping through hand lay‐up technique, GFRE tubes were fabricated with various weight percentages of NCP, that is, 0, 0.25, 0.50, 1, 2, 3, and 4 wt.%. Following that, the crashing load, total absorbed energy against displacement responses, and deformation histories of these tubes under quasi‐static axial loading conditions were calculated and tracked. As part of the crashworthiness analysis, critical indicators were evaluated, including initial peak load (Fip), total absorbed energy (U), mean crash force (Fm), crash force efficiency (CFE), and specific energy absorption (SEA). The findings reveal that the maximum Fip, U, Fm, and SEA were noted at 0.5 wt.% of NCP, with increasing percent's of 30.80, 12.17, 12.16, and 7.50, respectively, compared to the unfilled tube. While, the CFE was recorded by 3 wt.% of NCP with an enhancement of 16.67%. It is worth to note that, the findings reveal that the inclusion of NCP increases crashworthiness metrics up, that is, Fip, U, Fm, and SEA to a concentration of 0.50 wt.% NCP. However, beyond this point, there's a notable decline in performance. Highlights: The GFRE tubes were filled with various wt.% of NCP.The planned tubes were made using hand lay‐up methods.The tubes were subjected to axial compression loads to examine their crashing behavior.The crashing load and absorbed energy versus displacement responses for tubes were exposed.The experimental results were analyzed and discussed. [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach to enhance the absorption capabilities of skin‐core dual‐domain structure radar‐absorbing materials (SDSRAM) composed of thin‐ply laminates and honeycomb. The upper skin laminates consist of transmissive skin and impedance matching layer. The impedance matching layer was hot‐pressed using functionalized absorbed thin‐ply glass fibers prepregs, flaked carbonyl iron powder (FCIP) and multi‐walled carbon nanotubes (MWCNTs) as the absorber. The lower skin was manufactured using carbon fiber‐plated nickel. The core is prepared by honeycomb modified (HCM). The permittivity and permeability of the skin laminates and the HCM were measured by wave‐guide method. The impact of FCIP/MWCNT on the electromagnetic (EM) parameters of the thin‐ply laminates and the influence of MWCNTs on the permittivity of the honeycomb were investigated. Microwave absorption properties of SDSRAM were assessed through the measurement of reflection loss (RL) using the arch method and simulated using the microwave simulation software CST studio suite 2020. Experimental verification was conducted to confirm the absorbing performance. The results show that the effective absorption bandwidth (RL < 10 dB) of SDSRAM covers the frequency range of 2.2–18 GHz, with a maximum absorption intensity of −42.5 dB. The introduction of the thin‐ply laminates caused a shift in the peak of the reflectance curve toward lower frequencies. Highlights: Functionalized absorbed glass fibers were prepared using fiber spreading functional sizing integrated process.A new skin‐core dual‐domain synergistic modulation absorbed structure was developed with thin‐ply laminates and modified honeycomb. Its broadband absorption mechanism was discussed.Desired broadband absorption performance was acquired with thin thickness. [ABSTRACT FROM AUTHOR]

Biological structures achieve remarkable material performance owing to naturally assembled structures that extend from the molecular to macro‐scale. Synergy among constituents of various length scales yields lightweight, hierarchically structured materials with properties superior to those of individual components. To replicate nature's ingenuity, this work emulates the cylindrical core‐shell structure found in osteons and bamboo, utilizing Halloysite Nanotubes (HNTs) and Glass Fibers (GFs) in a semi‐crystalline polymer matrix. HNTs are environmentally friendly, naturally occurring tubular aluminosilicates with high aspect ratios, large lumen volumes, and low cost, and are readily dispersible in polymer matrices. Here, hierarchical reinforcement is achieved through controlled electrostatic assembly of HNTs onto GFs and subsequent trans‐crystallization‐encapsulation. This cylindrical core‐shell architecture yields composites with exceptional mechanical performance, superior thermal management (insulation/stability), improved industrial processability, and reduced flame propagation speed. Compared to the current industrial composite substitute for metallic structural components, the hybrid composites exhibit a remarkable 84% increase in impact strength, 27% increase in specific tensile strength, 56% increase in tensile toughness, and 30% in specific flexural strength, accompanied by a 20% weight reduction and a 255% increase in processability (melt‐flow index). This scalable assembly strategy marks a cornerstone in lightweight multifunctional materials development, to conquer future sustainability targets. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Material and Methods Results Conclusion To evaluate the plant‐derived compound lignin (LIG) as a pretreatment of intraradicular dentin in combination with EDTA on push‐out bond strength (PBS) and nanoleakage of the glass fiber posts (GFPs) cemented using adhesive resin cement.Twenty‐eight human incisor roots were prepared for GFP cementation and divided based on dentin pretreatment: (1) CONTROL: no pretreatment, (2) EDTA: 17% EDTA for 3 min, (3) EDTA‐LIG: 17% EDTA and 2% lignin for 3 min, (4) EDTA‐PAC: 17% EDTA and 2% lignin for 3 min. The GFPs were cemented using the self‐adhesive resin cement Multilink Speed. The roots (n = 7) were sectioned into 1 mm‐thick discs and subjected to PBS testing after 1 week or 6 months. Nanoleakage was analyzed by SEM. Statistical analysis was performed using two‐factor ANOVA and Tukey's test (p < 0.05).Higher PBS was identified for the CONTROL group (p < 0.001). After 6 months, the EDTA‐LIG maintained the bond strength with a predominance of mixed failures, while the EDTA‐PAC, EDTA, and CONTROL groups showed reduction of bond strength, with a predominance of adhesive failures along with severe silver infiltration in the interface.LIG associated with EDTA as a pretreatment for intraradicular dentin shows significant potential for attaining stable bond strength and interfacial integrity of self‐adhesive resin cement to intraradicular dentin. [ABSTRACT FROM AUTHOR]

Kevlar, Carbon and fiber glass are widely used in various kind of industries because of their superior properties like; great stiffness, high strength, wear resistance and low density those benefits contributed to increase their usage in different fields like electronics, automobile, aerospace and civil engineer. This study is carried out to improve the creep behavior of epoxy composite materials by incorporating two type of fiber for reinforcement using Hand-layup techniques. Sika epoxy resin is mixed once with Kevlar fibers, and once with Carbon fiber to produce a composite material. Experimental and numerical simulation are carried out to provide an extensive knowledge of the creep behavior of epoxy composite materials at various weight ratio. Visco-elastic materials creep strain and stress relaxation are analyzed utilizing Prony and Burger models. Based on the results, the addition of Carbon and Kevlar fibers to Sika epoxy composite increase its mechanical characteristics compare to pure epoxy. Carbon fiber possesses lowest creep strain and low stress level than Kevlar fibers. Sika epoxy composite containing 5% weight fraction of Carbon fiber has the highest resistance to creep, up to 80% more, compared with Sika epoxy; followed by Kevlar fiber which is up to 75% more, compared with Sika epoxy. The use of Carbon/Sika epoxy composite results in higher creep compliance and modulus of elasticity compared with Kevlar/Sika epoxy composite. [ABSTRACT FROM AUTHOR]

This study aimed to enhance the structural performance of a drift joint with a slotted-in steel plate using laminated timber made from small- to medium-diameter timbers. An analysis was conducted to compare and evaluate the structural performance and seismic behavior of laminated timber portal frames reinforced with fiber-reinforced plastic (FRP) laminates, such as glass fiber cloth (GFC), glass fiber reinforced plastic sheet (GS), and carbon-reinforced plastic sheet (CS), under low amplitude cyclic lateral loads, in comparison to unreinforced portal frames (UR). The reinforced portal frame, strengthened by FRP laminates, exhibited higher resistance to strength and stiffness strength degradation due to cyclic loading-induced degradation at low drift angles compared to the unreinforced frame affected by heterogeneous timber. The reinforced portal frame, particularly the GFC and GS, exhibited energy dissipation rates 32% and 17% higher than UR, respectively, making them the most effective in vibration damping. FRP laminates mitigated fiber direction cleavage from drift pin holes. The average maximum moment and average yield moment of the reinforced portal frame increased by 18% and 21%, respectively, due to the alleviation of joint failure. Finally, CS significantly affected the maximum moment, while GFC significantly influenced the yield moment. [ABSTRACT FROM AUTHOR]

Introduction: There is much debate over the best choice of restorative material and the placement method for the most successful treatment. Many teeth that have undergone endodontic treatment may not have enough structure to support a restoration or crown. To improve retention for the restorative material, ferrule may be used. Adhesive techniques have transformed the way we restore teeth after root canal treatment, starting with the shift from using cast post-and-core to using fibre post. The use of fibre-reinforced posts has been found to prevent irreparable root fractures thereby improving the longevity of the treatment. Aim: To compare two different types of aesthetic fibre posts for 12 months. Materials and Methods: A prospective interventional study was carried out in the Department of Prosthodontics, Manav Rachna Dental College (Faridabad) for a period of 12 months from Nov 2022-Oct 2023. Forty participants with single rooted, endodontically treated, maxillary anterior teeth in the age bracket of 15-55 years, both males and females of the north Indian population were included in the study. Teeth were selected where a post-retained crown was indicated and post space was prepared using a piezo reamer drill at 5000 rpm. At least 4 mm of obturation is left in the canal to maintain the apical seal. Furthermore, Zircon-enriched silicon fibre and glass fibrereinforced posts were cemented into the prepared post space. Metal-ceramic crowns were cemented and baseline periapical radiographs were obtained. At the interval of one month, three months, six months and one year, the patients were evaluated. The Fischer's exact test was utilised to establish the association between categorical variables and the level of significance (p-value <0.05). Results: One year follow-up revealed no failures in crown movement when evaluated under finger pressure, recurrent caries, or root fractures. One case of glass fibre-reinforced post showed a fracture of the post and another case of glass fibre post showed periapical radiolucency at 6-month intervals on clinical and radiographical examination which was significant when compared to Zircon-enriched silicon fibre post group (p-value=0.02). Conclusion: Both aesthetic fibre-reinforced post systems used in single-rooted upper anterior teeth demonstrated similar success rates in restoring root canal treated teeth. [ABSTRACT FROM AUTHOR]

This study investigated the influence of moisture absorption on the electromagnetic (EM) wave absorption performance and mechanical strength of a radar-absorbing structure (RAS) with nickel-coated pristine glass fibers and polyamide 6. To construct the RAS, nickel was deposited on pristine glass fibers via electroless plating, and the RAS was fabricated using a hot-press process. An environmental test was conducted under a high humidity of 85%, and the EM wave absorption capacity of the RAS was measured at 2-week intervals. Moreover, compressive and interlaminar shear tests were conducted to verify the degradation of mechanical strength and the effect of the nickel coating on moisture absorption resistance. The test results revealed that immersion in moisture degraded the EM absorption capacity of the RAS. Nevertheless, an improvement in the mechanical strength of the RAS after saturation was observed due to the nickel coating. [ABSTRACT FROM AUTHOR]

In this study, high loadings of boron nitride (BN) nanoplatelets were added to silica fiber-reinforced phenolic composites to study the multifunctional impact of BN loading and manufacturing processing on the subsequent mechanical, thermal, and thermomechanical properties. A series of high-quality laminates were made with various loadings of BN using compression-molded out-of-autoclave processing. Three-point bend and short beam shear testing determined the relationship between BN loading and mechanical performance. The fracture properties were analyzed using optical and scanning electron microscopy. The thermal conductivity performance was increased up to a 93% improvement, indicating the thermal management multifunctionality of the modified composites without changing the crosslinking ability or glass transition temperature significantly. The modified performance of hybrid silica/phenolic/BN composites is demonstrated through micromechanical multiscale modeling, where BN loading and particle stress concentrations impact the modulus and strength of the composite. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-objective optimization method for injection molding, combining the random forest (RF) model optimized using the light spectrum optimizer (LSO) with the non-dominated sorting whale optimization algorithm (NSWOA), to tackle the quality defects of warpage deformation and volume shrinkage commonly observed for the glass fiber injection molded product. Based on the simulation results of central composite face centered design (CCF), the model for control of injection molding quality defects using LSO-RF is constructed. NSWOA is used for multi-objective optimization to obtain the Pareto solutions, and the critic method is employed to determine the optimal process parameter scheme. Then, the optimal process parameter scheme is inputted to Moldflow for simulation verification. The validation results demonstrate that the LSO-RF model achieves prediction errors within 3 % for warpage deformation and volume shrinkage, indicating good predictive accuracy. The optimized warpage deformation and volume shrinkage are 0.3519 mm and 7.0930 %, respectively. Compared to the pre-optimized state, the warpage deformation decreased by 32.57 % and the volume shrinkage decreased by 15.93 %, indicating a significant improvement in molding quality for the glass fiber injection molded product. [ABSTRACT FROM AUTHOR]

Short-fiber reinforcement is a potent approach to improving the material properties of injection-molded parts. The main consideration in such reinforced materials is to preserve the fiber length, as this is the major influence on the properties of a given composite. The aim of this work was to investigate the different influencing parameters in injection molding processing on the properties of short carbon and glass fiber-reinforced polypropylene. We investigated parameters like melt temperature and back pressure, but also machine size and pre-heating regarding their influence on the tensile properties. We found that adjustments of melt temperature and back pressure only yield small improvements in the fiber length and the tensile properties, also depending on machine size, but a pre-heating step of the granules can significantly improve the properties. [ABSTRACT FROM AUTHOR]

Thermoplastic fiberglass was compression molded in the form of thick panels with a nominal thickness of 10 mm and a size of 300 × 300 mm2. A simplified procedure was adopted to speed up the lamination procedure and adapt it to the aim of recycling waste, glass fibers, fabrics, and thermoplastic films. Low density polyethylene was used as a matrix to simplify the laboratory process, but the same procedure can be extended to other thermoplastic film, such as polyamide. The final thermoplastic composite shows unique properties in terms of its repairability, and its performance was improved by increasing the number of repairing repetitions. For this aim, a repairability test was designed in the bending configuration, and three consecutive cycles of bending/repairing/bending were carried out. The static mechanical properties of the final thermoplastic composite were, conversely, low in comparison with traditional fiberglass because of the choice of a polyethylene matrix. The bending tests showed that the maximum strength was lower than 10 MPa and the elastic modulus was less than 1 GPa. Nevertheless, the toughness of the thermoplastic composite was high, and the samples continued to deform under bending without splitting into two halves. [ABSTRACT FROM AUTHOR]

This study investigates the repair of damaged curved glass/epoxy composite laminates through various adhesive reinforcements and adhesively bonded external patches. The experimental procedures involve fabricating laminates, conducting four-point bending tests, quasi-static indentation tests, and optimizing damaged areas. Results demonstrate the influence of repairs on curved beam strength and interlaminar tensile strength. Adhesive repairs with chopped fiber reinforcement outperform plain epoxy and particle fiber-reinforced repairs, preserving 51.28% of curved beam strength. Adhesively bonded external patches, both single and double, with chopped fiber reinforcement exhibit significant strength recovery 72.08% and 80.78% compared to virgin samples. The study emphasizes the effectiveness of adhesively bonded external patches, particularly those with chopped glass fiber reinforcement, in enhancing curved beam strength and interlaminar tensile strength. This research provides valuable insights for repairing angled structures, such as those in airplane components, showcasing potential applications of these techniques for structural maintenance. HIGHLIGHTS: Investigated adhesive reinforcements and bonded external patches for curved composites. Laminates fabricated, tested for bending, indentation, and optimized in damaged region Chopped fiber adhesive repairs preserve significant 51.28% strength. Adhesively bonded patches exhibit 72.08% and 80.78% strength recovery. [ABSTRACT FROM AUTHOR]

In the automotive industry, short glass fiber-reinforced thermoplastics are widely used under the hood and subjected to dynamic vibrations of the engine in multiple directions resulting in fatigue failure. Under fatigue loading, a significant portion of the strain energy is stored within the material, while the remaining portion is lost due to internal frictions and the damage occurrence. Internal friction results in heat generation, which in turn causes an increase in external temperature. This increase in temperature leads to thermal degradation of the polymer. Investigations on the cause of the stiffness drop are not widely available in the literature. Therefore, this study explores the source of the stiffness drop under biaxial fatigue loading of a polyamide 6,6 reinforced with 30 wt. % short glass fibers (PA66GF30) and distinguishes the contributions of thermal degradation and damage accumulation. The thermal evolution of the specimens was captured by means of thermography. In addition, the digital image correlation (DIC) technique was used to measure the in situ strain field during the fatigue. Despite the temperature stabilization being observed around the 10,000th cycle, the reduction in the stiffness continued until failure which was attributed to the mechanical damage accumulation and cyclic creep during the fatigue tests. Dynamic mechanical analyses (DMA) were carried out to quantify the stiffness drop with the varying temperature. From the results, it is seen that the damage accumulation and cyclic creep during the fatigue tests were responsible for the major part of the stiffness drop. Finally, scanning electron microscopy (SEM) inspection of the fracture surface was performed to identify fatigue damage mechanisms. Four unique features associated with the fatigue damage were identified: (1) debonding of fibers from the matrix, (2) polymer matrix crazing, and (3) cavitation and porosities, (4) pull out fiber ends and break on the fiber. [ABSTRACT FROM AUTHOR]

Users of the microbond test assume that a microbond resin droplet's properties are equivalent to a macroscale specimen. However, there is currently no standardised methodology for determining the cure state of droplet specimens used in the microbond test. In this paper, we present a technique for microbond test users to better understand the properties of thermoset droplet specimens. Utilising a conventional benchtop spectrometer, a novel sample preparation technique involving curing epoxy droplets on thin-steel filaments allowed for high-throughput determination of the microbond droplet cure state. The parity between steel filament and glass fibre microbond samples was confirmed by infrared microspectroscopy. It is shown that cure schedules used in manufacturing composite parts produced microbond droplets with degrees of cure lower than that of bulk matrix specimens subjected to an identical thermal history. Testable microbond droplets could only be prepared for commercial resin systems when introducing a room temperature pre-curing time of at least 2 h. It is concluded that microbond testing should be supported by some droplet cure state characterisation methods to ensure that interfacial effects are not artefacts of droplet sample preparation. [ABSTRACT FROM AUTHOR]

To evaluate the effect of different ratios of Bis-EMA/Bis-GMA resin mixtures on the inherent viscosity and curing-related properties: including degree of cure (DC%), shrinkage strain, Knoop micro-hardness (KH) and flexural strength of resin-impregnated fiber-bundles. Bis-EMA/Bis-GMA monomers were mixed (by weight) in the following ratios: M1 = 30 %/70 %, M2 = 50 %/50 %, M3 = 70 %/30 %, and M4 = 100 %/0 %. Standard measurements were made of refractive index, viscosity, degree of conversion, shrinkage strain and Knoop hardness (KHN). For 60 % glass fiber-bundles impregnated with 40 % resin, three-point bending test for flexural strength and shrinkage strain were measured. Data were analyzed by One-way ANOVA and Bonferroni post-hoc tests (α = 0.05). For resin mixtures, increasing Bis-EMA proportion decreased refractive index (p < 0.05), and viscosity (p < 0.05), and increased monomer conversion (DC%), shrinkage strain and KHN (p < 0.05). DC% increased after 1 h for all resin mixtures. The shrinkage strain and flexural strength of resin-impregnated fiber-bundles reduced with increased Bis-EMA. Monomeric mixtures with highest amounts of Bis-EMA showed enhancement in several clinically-relevant properties and polymerization of respective resin-impregnated glass fibers. This makes them potential candidates for impregnating glass fibers in fiber-reinforced restorations. [ABSTRACT FROM AUTHOR]

Geopolymer lightweight cellular concrete (GLCC) combines the advantages of geopolymer and LCC but also suffers from the inherent deficiency of low strength, which can be improved by introducing suitable reinforcing materials such as fibers. This paper investigated the mechanical properties and microstructure of fly ash-slag-based GLCC reinforced with glass fibers (GLCCRGF), aiming to reveal the strengthening mechanism of glass fibers. The effects of different fiber contents (0.0, 0.3, 0.6, 0.9, and 1.2%), fiber lengths (3, 6, 9, 12, and 15 mm), and fiber-blending methods (G-R, G-W, and G-S) on the mechanical properties of GLCCRGF were analyzed. The results showed that the fiber incorporation had no significant or even negative effect on the compressive strength but significantly improved the splitting tensile strength. The optimal results of fiber content, fiber length, and fiber-blending method are 0.6%, 9 mm, and G-R, respectively. From the microstructure perspective, optical tests were conducted to explore the evolution rules of pore size, pore shape factor, and fractal dimension of pore distribution of GLCCRGF. The results showed that the incorporation of glass fibers (0.6%, 9 mm, and G-R) improved the pore characteristics and contributed to more uniform pore distribution. Furthermore, scanning electron microscopy (SEM) was employed to observe the micromorphology of the skeleton structure of GLCCRGF. The SEM results showed excellent interfacial bonding between glass fibers and the geopolymer matrix. Due to good bonding quality and crack-bridging effect, the presence of glass fibers enhanced the strength and crack resistance of the matrix. [ABSTRACT FROM AUTHOR]

To effectively manage turbine blade weight and blade deflection under severe weather conditions, longer and stiffer blades are required, fiber glass producers have devoted significant efforts to developing and commercializing high‐modulus (HM) glass fiber products of the first generation. The current focuses aim at the commercialization of the second generation and the development of the third‐generation products. This article briefly reviews four key areas: (a) the benefit of longer blades on wind energy generation, (b) characteristics of HM glass fibers of various generations, (c) fundamental science and understanding behind HM glass fiber development, and (d) finally statistically based composition (C)–property (P) and structure (S)–property (P) modeling approaches in new glass design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Swelling-assisted pyrolysis was proposed for the recovery of glass fibers from WTBs. • Resin decomposition ratio reached 76.8 % at 350 °C in swelling-assisted pyrolysis. • The swelling treatment physically disrupted the cross-linked structure of the WTBs. • The oxidation duration was reduced owing to the less content of pyrolysis char. • Tensile strength of fibers from swollen-WTB was higher than that from original-WTB. The recycling of end-of-life wind turbine blades has become a global environmental challenge driven by the rapid growth of wind power. Pyrolysis is a promising method for recovering glass fibers from these discarded blades, but traditional pyrolysis is often operated at high temperatures, which degrades the mechanical properties of recovered fibers. To address this issue, a swelling-assisted pyrolysis method was proposed to recover high-quality glass fibers from end-of-life wind turbine blades at low temperatures. The results confirmed that the decomposition of the resin matrix within the blade was significantly promoted at low temperatures in the swelling-assisted pyrolysis process, achieving a resin decomposition ratio of 76.8 % at 350 °C. This improvement was attributed to enhanced heat transfer and co-pyrolysis with acetic acid. Swelling could physically disrupt the cross-linked structure of the blade, creating a more porous and layered structure, thereby enhancing heat transfer during the pyrolysis process. Simultaneously, the co-pyrolysis with acetic acid could generate hydrogen radicals, which promoted the cracking of macromolecular oligomers into lighter products or gaseous alkanes. Consequently, the formation of pyrolysis char within the solid pyrolysis product was reduced, shortening the oxidation duration to 30 min. In comparison to traditional pyrolysis, the swelling-assisted pyrolysis process effectively suppressed the diffusion of surface defects over the recovered fibers, leading to promising improvements in their flexibility, elasticity, and mechanical properties, with tensile strength notably increased by 27.5 %. These findings provided valuable insights into recovering high-quality glass fibers from end-of-life wind turbine blades. [ABSTRACT FROM AUTHOR]

The paper deals with the influence of the brittleness of glass fibers on the selected performance properties of the fibrous polymer composite. Understanding the fatigue behavior of fiber-reinforced plastics is desirable for exploiting their features in safe, durable, and reliable industrial components. Based on the proposed methodology, it is possible to assess the impact of material reuse on selected mechanical and rheological properties. To verify the methodology by experimental analysis, homopolymer PP reinforced with chemically grafted glass fiber (30 wt%) was selected. The proposed methodology was subsequently verified by experimental analysis and evaluated statistically. The morphology of the fracture surfaces was evaluated, and the fiber-polymer matrix adhesion was monitored at the interface of the fracture surfaces. Based on the measured and evaluated values and fracture surfaces, we can say that the brittleness of the fibers significantly affects the performance properties of the tested polymer composite. [ABSTRACT FROM AUTHOR]

In the plastic design and development of PLC controllers, the key is to control the flatness and deviation of the installation hole axis. The article uses simulation technology to calculate the flatness and axis deviation of the PLC controller after injection molding, and designs orthogonal tests to explore the influence of process parameters and optimization schemes. The orthogonal test results indicate that the maximum values of the flatness and axis deviation of the PLC controller under different combinations of process parameters are 2.5 times and 1.8 times of the minimum values, respectively, indicating that the influence of process parameters is significant. Taking into account the flatness or axis deviation, the optimal process parameter is A2B2C3D1. The simulation results of the optimized process show that the shrinkage estimation and gas cavity on the main appearance surface meet the requirements, and the injection pressure and clamping force are also within the normal range, verifying the feasibility of the optimized process. [ABSTRACT FROM AUTHOR]

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Most asbestos-related studies have focused on asbestos exposure risks, their associated health implications, and waste management issues. Our research introduced a unique perspective that has rarely been explored: the impact of environmental factors on asbestos cement products. The novelty of the study is that, in contrast to previous research, in addition to determining the material quality of asbestos, it analyses the trace materials, additives and the emissive nature of chrysotile fibers. This study aims to identify the chrysotile-asbestos content in three common asbestos cement products found in Hungary, with regard to the release of their fibers upon exposure to the environment and to identify trace elements that could be used to identify the origin and function of each of these products. Our analyses revealed the presence of chrysotile in each tested sample, with spectral matches ranging from 59.6% to 86.7%. Asbestos cement products exposed to various environmental influences for long periods showed a greater chrysotile emission capacity than those unexposed or hermetically sealed ones. Additionally, we established that all asbestos cement products contained glass fibers, with an average spectral match of 62.1%. We further identified polysilicate in the materials with an average spectral match of 66.0%, as it was included in asbestos cement products to enhance their heat resistance. Our results pave the way for a new methodology for assessing asbestos cement products with regard to the implementation of their trace element level assessments. [ABSTRACT FROM AUTHOR]

The incorporation of filler materials to enhance the properties of fibre-reinforced plastics is a prevalent practise in materials science. Calcium carbonate is a commonly used inorganic filler in composite fabrication. Eggshell, a rich source of calcium carbonate, offers an organic alternative to conventional inorganic fillers. This study investigates the efficacy of different types of eggshells as filler materials. Three variants, viz., unhatched raw eggshell, unhatched boiled eggshell, and post-hatched eggshell, were used to fabricate composite variants, which were then subjected to mechanical characterization and compared with unfilled composites. The results indicated that composites filled with unhatched eggshells outperformed those with post-hatched eggshells. Tensile testing revealed a significant enhancement in the tensile properties of all eggshell-filled composites in comparison to the unfilled ones. The composite variant filled with unhatched raw eggshell filler showcased the utmost tensile modulus and strength, with a notable 36% improvement in comparison with the unfilled variant. Similarly, flexural tests demonstrated a 53% increase in flexural strength for unhatched raw eggshell-filled composites over unfilled composites. SEM imaging confirmed these findings by showing crack arrests, deviations, particle distribution, and strong interfacial bonding in the eggshell-filled composites. [ABSTRACT FROM AUTHOR]

This study investigated the manufacturing processes for structural supercapacitors (SSCs) using smear molding (RS), resin transfer molding (RTM), and vacuum-assisted resin transfer molding (VARTM). Woven carbon fibers were used as the electrode, woven glass fibers as an insulating layer, and an alkaline/epoxy compound as the electrolyte. In the RTM process, due to the vacuum and the high-pressure injection of the electrolyte, the electrochemical and mechanical properties of the SSC can be greatly improved, and the void contents in the SSC can be reduced. The balanced electrochemical performance and mechanical properties of SSCs were observed in the range of epoxy content from 15 wt% to 30 wt%. This study contributes to the development of SSCs through the establishment of the fabrication process for improvements in part quality. The fabrication method demonstrated here can be directly applied by industries to produce even larger-scale SSCs, opening up new possibilities for practical implementation and scalability. [ABSTRACT FROM AUTHOR]