Unidirectional Fiber Research Articles

Mathematical simulation of transverse cut in the fiber of a composite reinforced with unidirectional fibers with linear cohesion cracks

In the reviewed paper, the case of a transverse displacement plane with two pairs of biperiodic (corresponding to the X and Y axes) cohesive cracks of unequal size, weakened by biperiodic circular holes, is considered. The circular holes are filled with reinforcing fibers and the surface is covered with a thin homogeneous non-metallic material of the same thickness. In this case, boundary issues between filler and coating, coating and matrix, and boundary issues along cohesion cracks are determined. For both cases, the solution to the problem is sought in the form of an analytical function with complex variables. According to the boundary conditions of the case, a system of unequal algebraic equations is found along the holes, and singular integral equations are constructed along the cohesion cracks. Currently, the singular integral equations are brought to the system of finite linear algebraic equations with the help of mathematical transformations. Both systems are solved together using the Gaussian method and the crack growth is determined using the stress intensity factor formulas at the crack tips. During the solution of the problem, the stress intensity coefficients at the end are found by the variation of the length of the cracks based on the radius of the circular holes.

Dynamic compressive properties of 2D-aligned steel fiber reinforced cement-based composites

Dynamic compression may happen in some protective cement-based composite structures. Cement-based composites are compressed at loading direction when subjected to dynamic compression, however expansion occurs in the direction perpendicular to the loading. As a quasi-brittle material, the expansion of the cement-based composites may result in the disintegration and hence the failure of the material. Incorporating steel fibers is a valid solution of reinforce the composites to resist dynamic compression. Usually, steel fibers are randomly dispersed throughout the composites. Actually, steel fibers with the same direction of the dynamic loading are ineffective. Only steel fibers perpendicular to the orientation of the dynamic compression load can they effectively restrict the expansion of the composites and enhance its dynamic compressive properties. So, cylindrical specimens using two-dimensionally aligned steel fiber reinforced cement-based composites (2D-SFRC) were prepared and tested. In specimens all steel fibers are perpendicular to the dynamic compression load, which limits the circumferential expansion and deformation of the specimens when subjected to dynamic compression and significantly enhances its performance resisting dynamic compression. When preparing 2D-SFRC specimens, the magnetic field was used to align steel fibers to achieve the two-dimensionally aligned steel fiber in specimens. Then, 2D-SFRC specimens were tested for their dynamic compressive properties. The results indicate that the dynamic compressive strength and toughness of 2D-SFRC specimens are significantly increased compared with unidirectional and random steel fiber distribution specimens. By analyzing the stress distribution and tensile force of steel fibers, the reinforcing mechanism of two-dimensionally aligned steel fibers was revealed. The two-dimensional alignment of steel fibers increased the number and the tensile force of fibers, which effectively restrained the circumferential expansion of the cylinder specimens.

Micromechanical modeling for longitudinal tensile property of unidirectional CFRP considering dispersion of fiber properties

Longitudinal tensile failure prediction has always been the focus of research on unidirectional (UD) Carbon Fiber Reinforced Polymer (CFRP). In this paper, the longitudinal tensile tests of unidirectional T800 grade carbon fiber reinforced epoxy resin composite were carried out first. The experimental stress–strain curves show that there are obvious progressive damages before the final failures of the specimens. However, this phenomenon is usually neglected in most of the existing investigations and tests to only obtain elastic modulus and ultimate strength. Thus, a Representative Volume Element (RVE) model based on micromechanics was established using finite element method, considering the randomness of fiber spatial distribution and fiber strength. The tensile strength of fiber monofilaments was assumed to follow a statistical two-parameter Weibull distribution. The failure process of UD composite under longitudinal tensile load was simulated by explicit finite element method. The stress–strain curves obtained by simulation are in good agreement with the experimental results. Finally, the influence of different boundary conditions on the calculation of the RVE was studied. It is found that the final failure strengths of the RVE with uniform displacement boundary conditions are similar to the case of periodic boundary conditions, while the former has higher computational efficiency.

Effect of Fiber Orientation and Volume Fraction on Young's Modulus for Unidirectional Carbon Fiber Reinforced Composites: A Numerical Investigation

The modulus of elasticity of unidirectional fiber-reinforced composites greatly depends on the fiber orientation and the fiber volume fraction. This paper investigates the effects of fiber orientation and fiber volume fraction using the commercially available Finite Element Analysis (FEA) software Abaqus. Carbon fiber is the reinforcing material, while epoxy is used as the matrix. Representative Volume Element (RVE) of the unidirectional carbon fiber reinforced composites are modeled in Abaqus, and the unidirectional tensile test is simulated to determine the modulus of elasticity for different fiber orientations and fiber volume fractions. The numerical results are verified by previously published results and by experimental results. It is found that the modulus of elasticity of the composite is maximum when the fiber inclination angle is 0°, i.e., the fibers are placed along the loading direction. As the fiber orientation angle increases, the modulus of elasticity also decreases and is almost constant after 45°. A linear increase in modulus of elasticity is observed for an increase in fiber volume fraction. This model will help the researcher to select the appropriate fiber orientation and volume fraction for a specific application.

Artificial neural network prediction of transverse modulus in humid conditions for randomly distributed unidirectional fibre reinforced composites: A micromechanics approach

This paper proposes an innovative micromechanics-based artificial neural network (ANN) method to efficiently investigate the transverse modulus of unidirectional fibre/epoxy composites under humid conditions. In this research, a novel approach is developed to establish relations between the geometrical, mechanical, and environmental properties of the microstructure and the material’s performance under transverse tension. A framework is developed to artificially generate periodic representative volume elements (RVEs) while taking into account the interphase region between fibre and matrix. The RVEs are analysed by the finite element method to obtain the transverse moduli of composites. Two-point correlation functions and principal component analysis techniques are applied to extract and compress statistical information from microstructure images. A database establishment framework is developed to create three batches of data with 1000, 2000, and 3000 sizes. An ANN-based prediction framework is developed by integrating 10-fold cross-validation and Bayesian optimisation to optimise the neural network architecture and establish an efficient structure-property linkage under the influence of humid conditions. The prediction results demonstrate the efficiency of ANN in mapping microstructural data to an effective transverse modulus. A parametric study by ANN reveals the role of microstructure geometrical features and humid environmental parameters on the transverse performance of the composite.

An anisotropic topology optimization procedure for continuous fiber reinforced polymer structures with biaxial fiber layout for improved intersection point design

Fiber placement technologies allow for manufacturing of complex-shaped composite parts with load-adapted fiber orientation. For design of corresponding structures, topology optimization is well-established. However, anisotropic topology optimization approaches are often limited to unidirectional fiber orientations. In truss-like topology optimized structures, the intersections between the individual trusses are subject to multiaxial stress states. For those, a unidirectional fiber orientation is not appropriate and may not be suitable for manufacturing.In this work we propose a topology optimization procedure that allows for unidirectional but also biaxial fiber orientations. The choice between unidirectional and biaxial fiber layout is based on the stress state within the finite elements. For the biaxial fiber layout, the first fiber angle is aligned with the maximum absolute principal stress direction, while the second fiber orientation is calculated using composite net theory.Results show that considering biaxial fiber orientations leads to fiber orientations that can be better manufactured by fiber placement technologies and are considered suitable for automatic derivation of manufacturing-tolerant placement paths. Furthermore, the stress state at intersections is improved reducing the probability of inter fiber failure. In addition, consideration of biaxial fiber orientations could increase the stiffness at constant weight compared to purely unidirectional topology optimization.

Study on projectile impact resistance of carbon-glass hybrid bioinspired helical composite laminate

Mantis shrimp dactyl clubs have excellent impact resistance due to their special helical structure. Meanwhile, hybrid fibre has become increasingly popular to improve the mechanical properties of composite materials. Based on the helical structure of the periodic region of mantis shrimp dactyl clubs and hybrid fibres, in this study, a hybrid fibre helical lay-up laminate (HHL) is designed. The laminates are prepared using unidirectional carbon fibre prepregs and unidirectional glass fibre prepregs. To study the protective performance and damage process of HHL, a light gas gun impact test and numerical simulation calculations were carried out on the specimens. The harvested protective capability of the HHL specimen was then compared with those of carbon fibre unidirectional lay-up laminate (CUL), carbon fibre helical lay-up laminate (CHL), and hybrid fibre unidirectional lay-up laminate (HUL) specimens. The ballistic protection capability of HHL at different helical lay-up angles was also explored. The testing results show that HHL has the best ballistic protection performance. HHL’s ballistic limiting velocity is 228.5 m/s, which is 49.5%, 30.8%, and 19.9% higher than those of CUL (152.8 m/s), CHL (174.7 m/s), and HUL (190.5 m/s), respectively. Finally, hybrid fibres with a 90° interlaminar helix angle were found to have the highest ballistic limiting velocity. The reason is that the larger interlaminar angle allowed more fibres to be involved in the protection, increasing the energy loss of the projectile and enhancing the protection of the laminate.

The impact of nitrogen-doped reduced graphene oxide reinforcement on the thermal and mechanical properties of CFRP

This study used experimental methods to investigate the impact of nitrogen-doped reduced graphene oxide particles (ND-RGOP) reinforcement on thermal and mechanical properties of unidirectional carbon fiber/ epoxy composites (CFRP). In the results, storage modulus and loss modulus significantly increase with the ND-RGOP addition. Besides, glass transition temperature is enhanced with the addition of 0.4 wt% ND-RGOP. In tensile mode, when compared to the baseline (0 weight% ND-RGOP) composites, the elastic modulus in the 0° direction (E1) enhanced by 8.25 % and 11.39 % with 0.4 (0.4 weight%) and 0.8 (0.8 weight%) ND-RGOP addition, respectively. Besides, the ultimate tensile strength of the 0.4 ND-RGOP/CFRP composites significantly reduced by 16.33 % and 53.08 % in both 0° and 90° directions, respectively, as a result of the fracture mechanism changing from fiber pull out and fiber cracking to fiber breakage which was confirmed by SEM investigations. Furthermore, both the compressive modulus and the shear modulus increased with ND-RGOP reinforcement over 10 %, although the ultimate compressive strength decreases with low ND-RGOP reinforcement. In conclusion, low concentrations of ND-RGOP addition improves the thermal and mechanical properties of CFRP laminates in elastic region, although high concentrations of ND-RGOP decreases the thermal properties.

Microstructure dependent transverse strength criterion for UD-CFRP composites via computational micromechanics and machine learning

The transverse strength of unidirectional carbon fiber reinforced polymer (UD-CFRP) composites is a high dimensional and nonlinear function of microstructure due to the wide scatter in mechanical properties and complex failure mechanisms, which is a challenging task to develop a general microstructure dependent strength criterion (MDSC) in theory or computation. Volume fraction and distribution of fibers are among the crucial influencing factors. A computational micromechanics and machine learning (ML) combined method is employed to uncover the transverse mechanical response of UD-CFRP composites. High-throughput finite element analyses (FEA) are performed to obtain the transverse behaviors of composites with varying fiber distribution and volume fraction under different loading states. They showed that fiber distribution has different effects on strengths in different failure modes, while the failure modes are closely related to loading states and fiber volume fractions. An ML model is then trained to characterize the relations between composite microstructure and composite strength. Then, the transverse strengths of 1000 new microstructures are predicted, which shows good agreement with FEA results, so that the MDSC of UD-CFRP is constructed by fully accounting for the influence of fiber distribution. Reliability of the method is verified by considering composites with various fiber volume fractions.

Designed and Analysed of Three Distinct Composite Material-Based Mano Leaf Spring using ANSYS

The leaf spring is an important component in vehicles because it provides a comfortable ride and stability to the vehicle. The need to replace leaf springs with stronger and more lasting leaf springs is a key challenge in the transportation and automotive industries. In addition to offering ride comfort and stability, traditional steel leaf springs have a significant impact on the weight of the car. Fibre reinforced polymeric composites, therefore, are appropriate materials for various applications due to their many exceptional properties, including high wear resistance, high strength, long fatigue life, corrosion resistance, and low density. Fiber-reinforced polymeric composites find extensive application in several technical sectors, such as automotive, aviation, military, and marine industries. The utilization of composite materials has become imperative in the automotive industry to attain weight reduction without compromising material strength, as fuel consumption and CO2 emissions have to be reduced. In this paper, three different types of composite-based mono leaf springs were designed and examined. The results of the investigations showed that the 0° unidirectional glass fiber system was unable to correctly produce the required spring rate. Consequently, many combinations of carbon and glass hybrid systems were studied. The analysis showed that the desired spring rate was produced by the material configuration of [0°6G / 0°2C / 0°22G] S. When the final results were contrasted with the FEA findings, it was found that they concurred.

Experimental and numerical study of the effects of fiber orientation on stress concentration of CFRE

Carbon fiber reinforced composites are broadly employed, as structural members, in many industrial applications especially in the avionic industry due to their high strength-to-weight ratio. Circular holes are commonly used in these members for fastening, bearing, reducing weight, and others. Therefore, several experimental and analytical studies were introduced to figure out the stress concentration behavior around the vicinity of the holes under different loading conditions. However, no reports are delivered to study the effect of fiber orientation on the stress concentration factor of unidirectional carbon fiber reinforced epoxy (CFRE) composites with a hole under tension. Thus, the current work is targeted to understand the relationship between stress concentration factor (SCF) and fiber orientation in CFRE orthotropic plates. The unnotched and notched composite samples, with four different fiber orientations, were experimentally investigated in a tension test. The SCF of samples was calculated using analytical and computational FE methods. The failure criterion of open-hole tensile (OHT) test samples was also analyzed. The experimental results demonstrated that there is no significant effect of fiber orientation on the normalized strength. Yet based on the stiffness matrix of isotropic materials, a pronounced effect of the fiber orientation on the SCF is detected when using analytical calculations. The present research arises the need for further investigations to find a correlation between experimental and analytical results of SCF in unidirectional CFRE with a central hole at different fiber orientations.

The Effect of Carbon-Based Nanofillers on Cryogenic Temperature Mechanical Properties of CFRPs.

In the present work, the effects of carbon-based nanofillers (0.5 wt%), i.e., graphene nanoplatelets (GNPs), carbon nanofibers (CNFs), and carbon nanotubes (CNTs), on the cryogenic temperature (77 K) mechanical properties of carbon fiber reinforced polymers (CFRPs) were investigated. The study utilized an ex situ conditioning method for cryogenic tests. The nanofillers were mixed with the epoxy matrix by a solvent-free fluidized bed mixing technique (FBM), while unidirectional carbon fibers were impregnated with the resulting nanocomposites to manufacture CFRP samples. Optical microscopy was employed to analyze the dispersion of the carbon-based fillers within the matrix, revealing a homogeneous distribution in nanocomposites containing GNPs and CNFs. Fracture toughness tests confirmed the homogeneity of the GNP-loaded systems, showing an improvement in the stress intensity factor (KC) by 13.2% and 14.7% compared to the unmodified matrix at RT (25 °C) and 77 K, respectively; moreover, flexural tests demonstrated a general increase in flexural strength with the presence of carbon-based nanofillers at both temperature levels (RT and 77 K). Additionally, interlaminar shear strength (ILSS) tests were performed and analyzed using the same ex situ conditioning method.

Using FGM concept in fiber-matrix coupling laws to predict the damage in carbon-Epoxy graded composite application in notched plate under thermo-mechanical loading

Reinforcement in composite and notched structures has long been the objective of many researchers. One of the commonly used solutions is hybrid composite. Other recently reemerged solutions are graded materials. These respond, according to their modes of solicitation, to the targeted resistance objectives. However, composites with UD (unidirectional) fiber quality limit the choice of structural grading solely based on their thickness. Using the finite element method and the ABAQUS calculation code, this work presents the embodiment through numerical prediction of an idea based on the concept of material grading by FGM function. The objective of this approach is to introduce the volumetric fraction of the FGM concept into the Fiber-Matrix mixing laws in UD composite. Thickness-graded composites are subjected to a volumetric fraction function raised to the power of a parameter called volumetric fraction index (n). These structures, according to the proposed concepts, are analyzed under thermomechanical loading. The proposed grading of these composites is based on the presence of fibers in the matrix, where the fiber is denser on one side, called the simple concept C-S. The other two symmetrical concepts, named C-2 and C-3, present denser fibers in the middle and on both sides of the plate, respectively. These proposed concepts aim to observe how damage is caused by different responses and levels. The results under the different analyzed parameters are evaluated and compared to the results of the two other non-graded composites, thus showing the limits of those that are graded in terms of properties. According to the thermomechanical loading, the proposed graded composite has demonstrated a resistance overcapacity by the grading index (n) or their locations by concept C1- and C-2 of fibers have played a role in optimizing this capacity. The results also show that damage is caused by deformation overcapacity.

Microscale and mesoscale modeling for compressive failure in unidirectional carbon fiber reinforced polymer composites with random distribution of fiber misalignments

AbstractCompressive strength and failure mode of carbon fiber reinforced polymer (CFRP) composites are affected by the severity of fiber misalignment. In this paper, numerical models based on computational micromechanics are proposed to investigate the correlation between fiber misalignment and compression failure. A single‐fiber micromodel including fiber, matrix, and interface phases is first developed to capture the influence of misalignment severity on the material failure mode. The failure longitudinal stress distribution in the fiber predicted by the micromodel indicates that the failure mode depending on the initial misalignment can be identified as uniform compression failure, compression‐bending combination collapse, and fiber buckle. A mesoscale 2D model with multiple fibers is then constructed to investigate the kink band formation. This model takes into account the distribution of fiber misalignments to capture the key geometric features of fiber misalignment that influent the compression failure in realistic composite materials at the structural scale. The results show that fiber misalignment angle amplitude, misalignment dispersion (characterized by the standard deviation), and misalignment wavelength are the key parameters of fiber misalignment, which have significant effects on compression strength and kink band geometry.Highlights Single‐fiber model to capture the effect of misalignment severity on failure mode. Multi‐fiber model with randomly distributed fiber misalignments. Failure mode depending on the severity of initial misalignment was identified. Key parameters of misalignment on compression strength and kink band geometry.

Investigation of the stress–strain state of a composite blade in ANSYS WorkBench

In this paper, the static strength of a UAV blade made of composite material was calculated. Composite materials have an advantage over traditional materials (metals and alloys) in the field of aviation - gain in weight, low sensitivity to damage, high rigidity, high mechanical characteristics. At the same time, the identification of vulnerabilities in a layered structure is a difficult task and in practice is solved with the help of destructive control. Composite materials available in the ANSYS materials library were used in the modeling: Epoxy Carbon Woven (230 Gpa) Prepreg woven carbon fiber in the form of a semi–finished prepreg impregnated with epoxy resin carbon fiber with Young's modulus E=230 GPa and Epoxy Carbon (230 Gpa) Prepreg is a unidirectional carbon fiber prepreg impregnated with epoxy resin with a Young's modulus E=230 GPa. Modern software products, such as ANSYS WorkBench, allow comprehensive investigation of the layered structure. Several variants of blade designs with different fillers as the median material were investigated. The forward and reverse destruction criteria based on the Tsai-Hill theory were used. The influence of gravity was not taken into account. It is shown that the developed blade design meets the requirements. Balsa wood, pine, aspen and polyurethane foam were chosen as the middle material of the blade. Pine and aspen wood were selected according to the criteria of their availability and having the lowest density. The materials library of the ANSYS WorkBench software package used does not have characteristics for all of them, so the characteristics of the selected materials (pines and aspens) were added manually. For modeling and calculations in the ANSYS WorkBench program, such characteristics as density, axial elastic modulus, Poisson's coefficients, shear modulus and tensile and compressive strength limits are required.

Characterization of Interlaminar Friction during the Forming Processes of High-Performance Thermoplastic Composites

Friction is a pivotal factor influencing wrinkle formation in composite material shaping processes, particularly in novel thermoplastic composites like polyetheretherketone (PEEK) and low-melting polyaryletherketone (LM-PAEK) matrices reinforced with unidirectional carbon fibers. The aerospace sector lacks comprehensive data on the behavior of these materials under forming conditions, motivating this study’s objective to characterize the interlaminar friction of such high-performance thermoplastic composites across diverse temperatures and forming parameters. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were employed to analyze the thermomechanical behaviors of PEEK and LM-PAEK. These data guided friction tests covering room-to-forming temperatures. Horizontal pull-out fixed-plies tests were conducted to determine the friction coefficient and shear stress dependency concerning temperature, pressure, and pulling rate. Below the melting point, both materials adhered to Coulomb’s law for friction behavior. However, above the melting temperature, PEEK’s friction decreased while LM-PAEK’s friction increased with rising temperatures. These findings highlight the distinct responses of these materials to temperature variations, pulling rates, and pressures, emphasizing the need for further research on friction characterization around glass transition and melting temperatures to enhance our understanding of this phenomenon.

Novel Bidirectional Output Ytterbium-Doped High Power Fiber Lasers: From Continuous to Quasi-Continuous.

Traditional ytterbium-doped high-power fiber lasers generally use a unidirectional output structure. To reduce the cost and improve the efficiency of the fiber laser, we propose a bidirectional output fiber laser (BOFL). The BOFL has many advantages over that of the traditional unidirectional output fiber laser (UOFL) and has a wide application in the industrial field. In theory, the model of the BOFL is established, and a comparison of the nonlinear effect in the traditional UOFL and the BOFL is studied. Experimentally, high-power continuous wave (CW) and quasi-continuous wave (QCW) BOFLs are demonstrated. In the continuous laser, we first combine the BOFL with the oscillating amplifying integrated structure, and a near-single-mode bidirectional 2 × 4 kW output with a total power of above 8 kW is demonstrated. Then, with the simple BOFL, a CW bidirectional 2 × 5 kW output with a total power of above 10 kW is demonstrated. By means of pump source modulation, a QCW BOFL is developed, and the output of a near-single mode QCW laser with a peak output of 2 × 4.5 kW with a total peak power of more than 9 kW is realized. Both CW and QCW output BOFL are the highest powers reported at present.

Unsaturated out-of-plane permeability measured with three-dimensional flow monitoring by etched optical fiber sensors

In our work, the three-dimensional flow in stacks of biaxial E-glass fiber non-crimp fabrics (NCF) and unidirectional carbon fiber layers was monitored by the etched optical fiber sensors embedded inside the fabric stack. The influence of embedding sensors with a diameter of 200 µm on the flow was experimentally illustrated and discussed. The out-of-plane permeability of the two fabric materials was estimated with a radial infusion model using the in-plane permeability values as the prior knowledge. The assumed radius of the semi-ellipsoidal flow was derived and showed a good agreement with the results obtained by the best fit of the exact solution, which provides an approximate solution that simplifies the calculation process. The asymptotic form and the modified semi-ellipsoidal inlet radius method for the case of a non-negligible radius of injection tube compared to the fabric sample thickness were verified. The uncertainties related to the unknown flow pattern near the inlet were also demonstrated. The presented results facilitate the further development and standardization of out-of-plane permeability measurement methods with embedded sensors.

Enhanced Estimation of Axial Compressive Strength for CFRP Based on Microscale Numerical Simulation and the Response Surface Method.

Compressive strength is one of the most important properties of carbon fiber reinforced plastics (CFRP). In this study, a new method for predicting the axial compressive strength of CFRP using the response surface method is developed. We focused on a microbuckling model to predict the compressive strength of unidirectional fiber composites. For the microbuckling model, axial shear properties are required. To obtain the compressive strength for various material properties, we perform individual shear tests and numerical simulations, but these require enormous computational costs and extended time. To address the issue of computational cost, in this study, we propose a new method to predict compressive strength using the response surface method. First, we perform shear simulation in a microscale fracture model for unidirectional CFRP with various parameters of the fiber and resin properties. Based on the results of the shear simulation, the response surface method is used to evaluate and develop prediction equations for the shear properties. This method allows for the study of the objective values of the parameters, without significant computational effort. By comparing both the results predicted from the response surface method (RSM) and the simulation results, we verify the reliability of the prediction equation. As a result, the coefficient of determination was higher than 94%, and the validity of the prediction method for the compressive strength of CFRP using the response surface method (RSM) developed in this study was confirmed. Additionally, we discuss the material properties that affect the compressive strength of composites comprised of fibers and resin. As a result, we rank the parameters as follows: fiber content, elastic modulus after resin yield, yield stress, and initial elastic modulus.

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

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