Fiber-reinforced Polymer Research Articles

Physico-mechanical characterization and DFT studies of benzoyl peroxide treated water hyacinth reinforced polypropylene composites

The use of eco-friendly natural fiber-reinforced polymer composites is rapidly expanding across diverse sectors. The rapid spread of water hyacinth disrupts aquatic ecosystems by modifying the pH of water and salinity in Bangladesh. This work investigated on the impact of incorporating both untreated and chemically treated water hyacinth fibers into polypropylene (PP). Untreated water hyacinth (UWH) powder was treated with an alkaline solution, producing mercerized water hyacinth (MWH). MWH was further oxidized to yield oxidized water hyacinth (OWH). Analysis of attenuated total reflection-fourier transform infrared (ATR-FTIR) spectra of UWH, MWH and OWH confirmed cellulose modification. The UWH and OWH were taken in varying contents (1, 2.5, 5, 7.5, and 10 wt%) and added to PP to make UWH-PP and OWH-PP composites using compression molding technique. The 1% fiber content OWH-PP composites exhibited enhanced tensile strength, elongation, and impact strength compared to UWH-PP composites. Enhanced mechanical properties in OWH-PP composites suggested that benzoyl peroxide treatment improves interfacial adhesion. Morphological analysis of the OWH-PP composite showed better interfacial bonding between water hyacinth and PP than that of the UWH-PP composite. Thermogravimetric analysis (TGA) depicted the thermal stability of the UWH-PP and OWH-PP composites. The chemical reaction of cellulose monomer was further studied with DFT/B3LYP level of theory using two different basis sets 6-31+G(d, p) and cc-pVTZ. The calculated vibrational spectra of the untreated, mercerized and oxidized cellulose monomer agree well with the ATR-FTIR spectra, confirming chemical modification. DFT calculations of thermodynamic properties revealed the feasibility of the reactions. Electronic property (NBO charge) indicated charge transfer and structural changes during chemical modification.

Fabrication and mechanical performance investigation of jute/glass fiber hybridized polymer composites: Effect of stacking sequences

The green, biodegradable, and cost-effective properties of natural fiber-reinforced polymer composite materials have attracted significant interest when compared to synthetic polymer composites. Jute is a naturally occurring bast fiber that is inexpensive, durable, and often utilized. In contrast, glass is a composite material that is frequently used in various applications, despite its high cost and potential environmental risks. Owing to jute's superior mechanical properties, there is a great deal of potential for combining it with glass, which would lower the amount of glass used and the composite's overall cost. This study employed bleached jute fabric and non-woven glass fabric to develop neat jute, neat glass, and hybrid composites by using different stacking sequences. The composites were fabricated utilizing a thermoset polymer matrix by following the hand layup process. Subsequently, an investigation was carried out to examine the mechanical, physical, thermal, and morphological properties of these composites. Out of the developed samples, the neat jute presents the least tensile and bending strength at 31.35 MPa and 41.138 MPa respectively, whereas the neat glass composite demonstrates exceptional tensile and bending strengths at 132.03 MPa and 184.86 MPa respectively. In the case of hybrid samples, they exhibited mechanical capabilities that fell between neat jute and neat glass, which was attributed to the combination of glass with jute fabric and the placement of glass as the outer layer. Apart from that, we observed that the moisture take-up% and thermal conductivity of hybrids composite were within 4–4.3% and 0.28–0.32 Wm−1 K-1 respectively. Moreover, thermogravimetric analysis and morphological behavior were also assessed. However, this study suggested that jute and nonwoven glass fabric with different stacking sequences may be combined to create a reinforced hybrid composite that may have potential use in furniture, interior design, and inner sections of cars.

Impact of drilling parameters on the surface roughness of egg shell filled glass fibre/polyester composites

Abstract Glass fiber-reinforced polymers (GFRPs) are widely used in domestic applications such as doors, windows, and furniture, where drilling is a common machining process. The surface roughness of drilled hole walls is a critical factor, particularly in fastening applications, where smooth finishes are essential. This study explores the influence of drilling parameters on the surface roughness of GFRPs reinforced with different types of eggshell fillers viz.,un-carbonized, carbonized, and hybrid along with an unfilled variant. The research employs a Central Composite Design within the Response Surface Methodology (RSM) framework to investigate the effects of material type, spindle speed, feed rate, and point angle on surface roughness. Material type and point angle were treated as categorical variables, while spindle speed and feed rate were continuous, each with four levels, resulting in 16 experimental runs. The results showed that surface roughness values varied from 3.04 to 4.99μm, depending on the specific combination of drilling parameters. Statistical analysis using Analysis of Variance (ANOVA) confirmed that spindle speed and feed rate significantly impact surface roughness, with roughness increasing at higher speeds and feeds. Notably, the carbonized eggshell-filled GFRP variant achieved the lowest surface roughness. The study also developed a highly accurate regression model, validated through experimental data. The novel use of different variants of eggshell fillers in GFRPs provides a sustainable and effective way to enhance material properties. Further, conducting the drilling studies to observe the outcomes, offers potential industrial applications in the production of high-quality, durable composite materials.

Dynamics of non-Newtonian fluid–fiber interactions and void formation mechanism based on fused filament fabrication

Due to the presence of internal defects such as voids in the composites manufactured by material extrusion additive manufacturing (MEX AM), the mechanical properties of the composites are significantly below the theoretical optimum. Under this circumstance, this paper is intended to investigate the effects of nozzle feeding angles and to analyze the void formation and evolution of multiphase flow, in which systematic computational fluid dynamics numerical simulations are conducted. The volume of fluid model and overset grid method are used to simulate the extrusion deposition process of carbon fiber-reinforced polymer composites, and the Carreau model is used to represent the shear-thinning behavior of molten polymer. The numerical method is validated against previously experimental and numerical simulation data. The numerical results show that the key factor leading to void formation is the vortices caused by fiber oscillation. The intense vortex at the front end of the fibers disrupts the interface between molten polymer and air, creating a beneficial condition for air to enter. Nozzle tilting can effectively reduce the probability of void formation by decreasing the fiber oscillation velocity. The results of the present study provide insights into the development and optimization of printer nozzles to enable the printing of longer fibers with less probability of potential void formation.

Durability of Implant Restorations with a Fiber-Reinforced Polymer Framework

Durability of Implant Restorations with a Fiber-Reinforced Polymer Framework

Heat partition evaluation during dry drilling of thick CFRP laminates with polycrystalline diamond drills

Since various material properties of carbon fiber-reinforced polymer (CFRP) are temperature dependent, dry drilling of CFRP is a delicate process. Thermal damage can be caused by a rise in temperature during drilling due to a large portion of heat being transferred into the material. Heat partition is used to quantify this, which represents the percentage of total heat being dissipated into the constituent objects during a machining operation. Drill margin and contact conditions at the tool-workpiece interface significantly affect the drilling of CFRP material. Drilling experiments were performed to measure thrust force, torque, and temperatures for five different sets of feed rates and rotational speeds. This study proposes a method for calculating heat partition values during CFRP drilling by developing a finite element-based thermal model. The FE model employs a Gaussian distributed ring-type heat flux that is a function of the equivalent contact length at the interface between the drill and the material surface and the geometry of the workpiece which operates as a moving heat source, emulating the progress of the drill through the CFRP laminate. The tool implements heat fluxes that use characteristic time-point-based step functions to represent the temperature on the drill as it advances through the workpiece during machining. The temperature profiles obtained from the FE analysis and the experiments for the workpiece and tool were subsequently matched iteratively to determine the corresponding heat partition value.

Assessment of recycling and repair methods for discontinuous glass fiber reinforced vitrimer composites with reclaimed parts

In the context of fiber-reinforced polymer composites, the pursuit of sustainability is of paramount importance to promote environmentally responsible practices. Vitrimer materials have recently gained significant attention for their potential to enable repair and recycling, rendering them an attractive choice for manufacturing eco-friendly composites while maintaining mechanical strength akin to a thermoset resin like epoxy. This study specifically focuses on glass fibers, and delves into the examination of mechanical properties using both chemical and mechanical recycling methods for quasi-isotropic, randomly dispersed discontinuous glass fiber-reinforced vitrimer composites. It places specific emphasis on the optimization of factors to promote sustainable production. The findings indicate that chemical recycling methods are remarkably effective, resulting in the almost complete restoration of mechanical properties when appropriately selected process parameters are applied. Additionally, this study investigates diverse repair techniques, with the overlap repair method exhibiting the highest degree of recovery. These findings underscore the remarkable potential of glass fiber reinforced vitrimer composites, characterized by their high mechanical properties, for applications in various industries, particularly in structural contexts. Overall, this study highlights the significant reduction in composite waste achievable through recycling and repair strategies, aligning with the broader goal of advancing sustainability within the domain of engineering and manufacturing.

Experimental study to unraveling the seismic behavior of CFRP retrofitting composite coupled shear walls for enhanced resilience

This study focuses on the empirical examination of the nonlinear seismic performance of carbon fiber-reinforced polymer (CFRP)-strengthened composite coupled reinforced concrete (RC) shear walls. The experimental setup involves testing the structure in two distinct states, wherein CFRP sheets are utilized for retrofitting and reinforcement. In the initial phase, three samples undergo reinforcement utilizing distinct patterns of CFRP sheets. In the subsequent stage, an additional trio of specimens is fabricated and tested without the application of CFRP sheets. Subsequently, all structures are exposed to a load equivalent to 60 % of their flexural capacity. Following this, the tested specimens undergo retrofitting with CFRP sheets, utilizing the same patterns as in the initial phase. The retrofitted composite coupled shear walls are then subjected to retesting. The principal aim of CFRP retrofitting is to amplify the flexural and shear capacities of the specimens, empowering them to endure heightened seismic loads in comparison to their original configurations. This research contributes by evaluating ductility, ultimate strength, energy dissipation, and construction costs associated with composite coupled steel plate-concrete shear walls. All specimens underwent cyclic loading in accordance with the ATC-24 guidelines [1], which provide standard protocols for testing the cyclic performance of structural components. These guidelines, outline procedures for simulating seismic loading conditions in laboratory settings to evaluate the performance of structural systems under cyclic loading. Finally, a parametric study explores the impact of CFRP sheets and their adhesion patterns on the seismic behavior of composite coupled shear walls. The selection of the optimal retrofitting scheme considers the construction cost of each specimen based on the total area of CFRP sheets utilized.

Investigating the role of fibre-matrix interfacial degradation on the ageing process of carbon fibre-reinforced polymer under hydrothermal conditions

The aqueous environment can deteriorate the fibre-matrix interface of carbon fibre-reinforced polymer (CFRP), significantly impairing the non-fibre-dominated mechanical properties. Thus, this study aimed to quantitatively analyse the impact of interfacial degradation on the hydrothermal ageing mechanism and process of the CFRP. Firstly, entire water absorption process of the CFRP under hydrothermal conditions was divided into three stages according to experimental measurement of its water content. Based on this division of stages, a novel water diffusion model was established for the hydrothermally aged CFRP. To measure the mechanical degradation, tensile tests were conducted on unaged, aged, and redried neat epoxy and transversely positioned unidirectional (UD) CFRP specimens. It was found that the transverse tensile strength degradation of UD CFRP was irreversible due to the permanent interfacial debonding between the fibres and matrix, in contrast to the reversible ageing of the epoxy matrix. To further quantify the fibre-matrix interfacial ageing, physically-based models were established for the degraded interfacial strength of CFRP subjected to hydrothermal conditions. After the characterization of the modelling coefficients, the physically-based models can be employed to predict interfacial strength inside the aged CFRP for various ageing durations. The prediction error was only 4.57% for the transverse tensile strength of degraded UD CFRP with various ageing durations from the representative volume element (RVE) simulation with its interfacial strength provided by the physically-based models, validating the effectiveness of the proposed physically-based models for degraded fibre-matrix interface under various ageing conditions.

Shear capacity prediction of carbon-fibre-reinforced polymer mesh fabric (CFRP-MF) stirrups reinforced concrete beams

Fibre-reinforced polymer mesh fabric (FRP-MF) is an effective substitute for normal steel stirrups in concrete to prevent steel corrosion in reinforced concrete (RC) structures. Nevertheless, methods for calculating the shear resistance of RC members rehabilitated in shear with FRP-MF configurations are lacking. Moreover, the methods for quantitative analysis of the shear contribution caused by the cracking control effect produced by CFRP-MF longitudinal FRP strips are unclear. In this paper, a mechanics-based segmental model is presented based on partial interaction analysis considering both transverse FRP strips and longitudinal reinforcements. By incorporating the carbon-fibre-reinforced polymer mesh fabric (CFRP-MF) stirrups into this model, a shear strength model was proposed and extended for design purposes in a closed form. In addition, the modified compression field theory (MCFT) model considering the shear strength of concrete in compression and the shear friction model (SFM) in the literature were appropriately modified and used for comparison with the segmental model. It should be noted that if the tensile strength of the longitudinal strips was added into the corresponding calculation formulas, it would cause the difference between the proposed novel models with the previous models. Finally, the shear strength of 14 CFRP-MF reinforced concrete beams were evaluated using these three models. The average ratios of the experimental values of the CFRP-MF RC beams to the shear capacity predicted by the modified segmental model, MCFT with the shear contribution of compressed concrete and SFM were 1.30, 1.19 and 1.19, respectively. It turns out that the modified mechanics-based segmental model yields the minimum discreteness based on the experiment results. This study can provide shear capacity calculation and design reference of RC beams with longitudinal FRP strip reinforcements for researchers and engineers.

Evaluation of glass fiber-reinforced polymer bars for application in sections of reinforced concrete

In order to evaluate the effectiveness and acceptability of glass fiber reinforced polymer (GFRP) bars as a substitute for conventional steel reinforcement, this study looks into their use in reinforced concrete sections. To assess the mechanical qualities of GFRP bars, the research includes mix design, casting, and extensive testing, such as flexural and tensile tests. Furthermore, a comprehensive study of GFRP-integrated reinforced concrete building sections is carried out, looking at factors like primary stresses, bending stresses, shear stresses, and deflection. Additionally, using ANSYS software, a comparative study of beam-column junctions using GFRP and RCC sections is conducted to evaluate structural performance under various loading circumstances. The results demonstrate how GFRP bars can improve building projects' structural integrity, toughness, and sustainability

Physical, Mechanical and Thermal Characterization of Areca, Pineapple and Glass Fiber Reinforced Polymer Composites for Aerospace Applications

In the current scenario, the focus on applying natural fiber-reinforced polymer composites in aerospace applications has increased tremendously due to their attractive characteristics such as lightweight, higher strength-to-weight ratio, good thermal stability at environmental temperatures, resistance to corrosion, sound absorbing capability and increased fuel efficiency. Further, studies on Bi-directionally oriented fiber composites have more advantages than the random or unidirectional orientation, such as uniform stress distribution and improved bonding at the interface. So, the present work focuses on using the Areca, Pineapple Leaf Fiber (PALF) and Glass fiber as the bi-directional fiber mat for reinforcing it into Epoxy polymer. The three different materials were fabricated by changing the fiber type with constant volume fraction and orientation. The martial characterization was done on the fabricated composites in order to evaluate their orientation effectiveness through density, moisture absorption, tensile, impact, hardness and thermal degradation. The bonding relationship was analyzed through a Scanning Electron Microscope. The results showed that the properties obtained were higher for the PALF composite than the areca composites due to the fact that the higher surface area of PALF fibers is confirmed through SEM analysis.

The impact of using prestressed CFRP bars on the development of flexural strength

Abstract The load-carrying capacity and ductility of conventional steel reinforcement may be greatly increased by using ordinary and prestressed carbon fiber-reinforced polymer (CFRP) bars, resulting in reinforced concrete structures with greater sturdiness. This research investigates the flexural behavior of CFRP-prestressed beams with bonded tendons as opposed to conventional steel-prestressed beams. This article examines a less explored topic that often fails because post-tensioned beams with unbonded CFRP tendons are crushed by concrete. The linear-elastic behavior of CFRP accounts for much of the experimentally observed considerable variations in flexural characteristics between CFRP and steel-prestressed beams. Compared to unbonded CFRP specimens, bonded CFRP specimens are much stronger. Our knowledge of CFRP reinforcement in concrete infrastructure is advanced by this work, which highlights the need for better design techniques to increase strength and ductility. It is recommended that CFRP bars be bonded with epoxy resin to restrict fast energy dissipation and avoid concrete failure. As a result, CFRP-reinforced concrete beams will react less linearly and more ductilely. CFRP may improve prestressed concrete beam performance and lifespan in a number of scenarios, as shown by comparative research with traditional steel reinforcement. Six 1,800–mm-long RC beams with a 200 × 300 mm cross-section were examined and divided into three groups, analyzing important loading phases (i.e., cracked, ultimate, and mid-span deflection) using CFRP bars as prestressed tendons to replace the bottom steel rebars. The load-carrying capabilities and ductility of CFRP-reinforced beams were much greater than those of the reference beam. A single beam using normal CFRP bars for reinforcement showed a 21.2 mm mid-span deflection and an ultimate load of 157.2 kN, with a 57.7-kN fractured load. Another beam with normal CFRP bars also showed enhanced performance, with a mid-span deflection of 21.2 mm, an ultimate load of 160.6 kN, and a cracking load of 57.5 kN.

GFRP-Reinforced Concrete Columns: State-of-the-Art, Behavior, and Research Needs

This comprehensive review paper delves into the utilization of Glass Fiber-Reinforced Polymer (GFRP) composites within the realm of concrete column reinforcement, spotlighting the surge in structural engineering applications that leverage GFRP instead of traditional steel to circumvent the latter’s corrosion issues. Despite a significant corpus of research on GFRP-reinforced structural members, questions about their compression behavior persist, making it a focal area of this review. This study evaluates the properties of GFRP bars and their impact on the structural behavior of concrete columns, addressing variables such as concrete type and strength, cross-sectional geometry, slenderness ratio, and reinforcement specifics under varied loading protocols. With a dataset spanning over 250 publications from 1988 to 2024, our findings reveal a marked increase in research interest, particularly in regions like China, Canada, and the United States, highlighting GFRP’s potential as a cost-effective and durable alternative to steel. However, gaps in current knowledge, especially concerning Ultra-High-Performance Concrete (UHPC) reinforced with GFRP, underscore the necessity for targeted research. Additionally, the contribution of GFRP rebars to compressive column capacity ranges from 5% to 40%, but current design codes and standards underestimate this, necessitating new models and design provisions that accurately reflect GFRP’s compressive behavior. Moreover, this review identifies other critical areas for future exploration, including the influence of cross-sectional geometry on structural behavior, the application of GFRP in seismic resistance, and the evaluation of the size effect on column strength. Furthermore, the paper calls for advanced studies on the long-term durability of GFRP-reinforced structures under various environmental conditions, environmental and economic impacts of GFRP usage, and the potential of Artificial Intelligence (AI) and Machine Learning (ML) in predicting the performance of GFRP-reinforced columns. Addressing these research gaps is crucial for developing more resilient and sustainable concrete structures, particularly in seismic zones and harsh environmental conditions, and fostering advancements in structural engineering through the adoption of innovative, efficient construction practices.

A simplified load-slip model for composite FRP-to-concrete tie with anchors for lateral performance prediction of strengthened squat RCSWs

This study addresses the critical need to enhance the lateral performance of existing reinforced concrete shear walls (RCSWs) that have become vulnerable to lateral loads due to outdated design codes and seismic activities. The paper introduces a novel tri-linear constitutive model for composite fiber-reinforced polymer (FRP)-to-concrete ties to predict the lateral behavior of RCSWs subjected to lateral loads. A simplified strut-and-tie model (STM) was employed, integrating a novel tri-linear model for FRP-to-concrete ties with the bond-slip and anchorage effects. Non-linear pushover analysis was conducted to simulate the lateral performance of FRP-strengthened RCSWs. The conducted STM was validated through experimental and numerical data from existing studies to assess its accuracy. The tri-linear constitutive model effectively predicted the lateral load and displacement capacities of FRP-strengthened RCSWs, accurately simulating both diagonal shear and flexure failure modes. Moreover, this model is applicable to both cracked concrete substrates and full-scale walls, accommodating various types of FRP composites, and different anchoring configurations, offering a robust tool for the seismic assessment of existing structures. The model was also applied to multi-story buildings, proving robust in handling complex geometry and offering enhanced computational efficiency compared to finite element (FE) analysis. This study confirms the applicability of the proposed model for practical use in assessing and designing FRP-strengthened RCSWs, offering a faster alternative to complex finite element analysis without sacrificing accuracy.

Thermal insulation and fire protection plaster for FRP systems incorporating aerogel nanoparticles and phyllosilicates

Fiber Reinforced Polymers (FRP) Systems are the most advanced systems in structural repair and strengthening field for their minimal time of application, limited space needed, and high durability. However, FRP systems still have a major drawback that limits their utilization in many projects, namely low fire-resistance. A novel material that was introduced lately with a substantial thermal performance is Aerogel, which has been widely utilized in other fields. This study attempted to develop fire-protective plaster incorporating nano silica-aerogel particles and phyllosilicates. During the experimental process, different surfactants were assessed as wetting agents, and their impact on both cement and mineral matrices. Finally, the selected plaster was evaluated under fire conditions. The results reveal that aerogel incorporation in mineral (gypsum) matrix was successfully achieved using various types of surfactants. The mechanical and thermal performance of the developed plasters were promising, with a fire-rating performance reaching 82 minutes for FRP system.

Chemical characterization of hibiscus rosa-sinensis plant fibers facilitated through design of experiments and artificial neural network hybrid approach

The integration of natural fibers into Fiber Reinforced Polymers (FRPs) has emerged as a promising avenue for sustainable and high-performance composite materials. Natural fibers, derived from plants, offer notable advantages such as renewability, low cost, and environmental friendliness. Among these natural fibers, Hibiscus Rosa-Sinensis (HRS) plant fibers have gained significant attention owing to their widespread availability and unique mechanical properties. In this study, HRS fibers were chemically treated using Sodium Hydroxide (NaOH), Potassium Permanganate (KMnO4), and Acetic Acid (CH3COOH) at different weight percentages (3, 4, 5 Wt.%) and solutionizing times (1, 2, 3 h) based on Taguchi’s L27 orthogonal array. The fibers, extracted from epidermis of the stems, underwent cleaning and chemical treatment after water retting. The crystallinity index, determined via X-ray Diffraction (XRD), indicated a maximum value of 65.77%. Thermo-gravimetric analysis (TGA) exhibited a degradation temperature of 365.24 °C and a material loss of 63.11%. Potassium Permanganate treatment at 4 Wt.% and 3 h of solutionizing time has yielded the best results. Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) has been successfully applied to accurately predict the output physical characteristics of chemically treated HRS fibers using experimental data. The results are in close alignment with the literature. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) analyses have provided valuable insights into the microstructure and constituents of the chemically treated HRS fibers. This research emphasises on the effectiveness of the chemical treatment process in enhancing the properties of HRS plant fibers for potential composite applications.

Novel 3D FRP system used for more effectively and readily strengthening of precast concrete elements

The burgeoning precast concrete market necessitates innovative strengthening solutions to ensure the durability and safety of precast elements. This study presents a 3D Fiber Reinforced Polymer (FRP) system designed to reinforce precast concrete elements, providing a more effective and efficient method compared to traditional Externally Bonded (EB) and Near Surface Mounted (NSM) FRP techniques. The system utilizes extended FRP strips that function as bent anchorages, U-wraps for anchorage protection, and additional FRP patches to prevent anchorage cutoff at bent corners. A comprehensive experimental campaign involving 33 specimens assessed the system's performance, demonstrating significant improvements in flexural and shear capacities with minimal surface preparation requirements. The experiments included varying strip widths and anchorage configurations to optimize the system's effectiveness. Numerical models were developed to simulate the flexural behavior of the 3D FRP reinforced elements, accurately predicting load-deflection responses and failure modes. Both experimental and numerical results suggest that the 3D FRP system not only enhances the load capacity and structural integrity of precast concrete elements but also simplifies the installation process, offering a promising solution for the construction industry. The findings also offer practical guidelines for the design and fabrication of 3D FRP reinforced concrete elements, contributing to a more sustainable and economical construction approach.

EARTHQUAKE-RESISTANT BUILDING DESIGN: INNOVATIONS AND CHALLENGES

This study provides a comprehensive systematic review of innovations in earthquake-resistant building design, focusing on advancements in materials, technologies, and methodologies aimed at enhancing structural resilience. A total of 32 peer-reviewed articles were analyzed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The findings highlight the critical role of advanced materials such as fiber-reinforced polymers (FRPs) and shape memory alloys (SMAs) in improving seismic performance, particularly through enhanced energy dissipation and structural flexibility. Technological integrations like Building Information Modeling (BIM), artificial intelligence (AI), and structural health monitoring (SHM) systems were identified as transformative tools that optimize design processes, predict structural vulnerabilities, and enable real-time risk management. Advanced simulation techniques, including finite element analysis (FEA) and computational fluid dynamics (CFD), were shown to significantly improve the accuracy and efficiency of seismic design. Despite these innovations, challenges related to cost, regulatory inconsistencies, and limited access to cutting-edge technologies persist, particularly in developing regions. The study concludes that while these advancements have revolutionized earthquake-resistant design, further efforts are needed to address these barriers and promote global resilience to seismic hazards.

Enhancing flame retardancy and mechanical strength of glass fiber-reinforced biomass polyamide composites with surface-functionalized black phosphorus

Fiber-reinforced polyamide exhibits exceptional mechanical properties and durability; however, its widespread application is impeded by potential fire hazards. In this study, a hybrid material consisting of black phosphorus (BP) and polyhedral oligomeric silsesquioxane (POSS) was synthesized, denoted as BP-CO-POSS. The fire safety of fiber-reinforced polyamide demonstrated significant enhancement upon the incorporation of aluminum diethyl phosphinate (Alpi) and BP-CO-POSS. This enhancement was evident in various aspects, including the suppression of heat release behaviors, reduction in the emission of toxic gases, and an increase in the UL-94 rating. Notably, with the additional inclusion of 0.5 wt% BP-CO-POSS, a substantial decrease in both heat release rate (31.15 %) and total heat release (37.59 %) was observed when compared to the application of Alpi and BP alone, thus affirming the existence of a synergistic effect. This observation was substantiated through a comprehensive analysis of results obtained from both gas and condensed phases. This study offers a practical methodology for the widespread utilization of phosphorus-rich advanced materials, thereby further enhancing the fire safety of fiber-reinforced polymers.