Fiber Volume Fraction Research Articles

Study on the performance of coal gangue ceramsite steel fiber high strength concrete

Our study aims to use coal gangue ceramsite (CGC) as coarse aggregate and add an appropriate volume fraction of steel fiber to prepare high strength concrete with lighter weight and meeting pumping requirements. The effects of (w/b) ratio, CGC content, the volume fraction of steel fiber, and water reducing agent content on the properties of coal gangue ceramsite steel fiber concrete (CGCSFC) were analyzed by orthogonal test, range analysis, and variance analysis. The optimal mix proportion of CGCSFC was obtained by using the efficacy coefficient method combined with the AHP-CRITIC method. The results showed that the crushing value of CGC was 37.26 % lower than that of coal gangue (CG). The reason for the increase in the strength of CGC was that there were few micro-cracks in CGC and the increase in quartz content. The (w/b) ratio had the most significant effect on the compressive strength of CGCSFC. CGCSFCs with compressive strength of 60–90 MPa and slump of 140–220 mm were prepared. The dry apparent density of CGCSFC with the same strength grade was 18.2–19.4 % lower than that of normal concrete (NC), and the specific strength was increased by 19.7–36.3 %. The average calculation error of Bowromi modified formula considering CGC content and the volume fraction of steel fiber is 3.82 %.

Distributions of coarse aggregate and steel fiber in ultra-high performance concrete: Migration behavior and correlation with compressive strength

The vertical distribution of coarse aggregates and steel fibers in ultra-high performance concrete (UHPC) both at fresh and hardened states was investigated to unveil their migration behavior and the correlation with compressive strength. To fulfill this purpose, customized design of specimens and tailored test method were developed. Specimens with two sizes (3–5 mm and 5–10 mm) and varying content (0–50 %) of coarse aggregate and different volume fraction of steel fiber (0–2 %) were proportioned. It was found that higher amount of coarse aggregates was located in the lower part whereas more steel fibers and voids were observed in the upper region of the specimens. Increasing the content of coarse aggregates resulted in worsened uniformness of its distribution, while incorporating steel fibers up to 2 % by volume imposed negligible effects on the heterogeneity. Migration of different phases primarily occurred during the fresh state. Compressive strength of the specimens at the middle layers was up to 30 % higher than those at the top and bottom layers. The inferior compressive strength was primarily ascribed to the worsened distribution of CAs and higher voids in the top layer.

Intra-yarn fibre hybridisation effect on homogenised elastic properties and micro and meso-stress analysis of 2D woven laminae: Two-scale FE model

In this paper, the effect of intra-yarn fibre hybridisation on the homogenised elastic properties and micro- and meso-scale matrix stress fields in 2D woven composite laminae (i.e. plain, 2/2 basket, 2/2 twill and 5-harness satin) is studied with a two-scale homogenisation scheme—employing a representative volume element model at micro-scale and a repeating unit cell model at meso-scale. The study is focused on S-glass/polypropylene/epoxy woven laminae with intra-yarn fibre hybridisation. A modified random sequential expansion algorithm generates microstructure for the micro-mechanical model, and a periodic meso-structure is used to generate the weave architecture for the meso-mechanical model. Both models are verified using analytical models. It is found that intra-yarn fibre hybridisation can significantly alter the homogenised properties as well as the micro- and meso-scale matrix stress fields—depending on the degree of hybridisation (i.e. the combination of S-glass and PP fibre volume fractions). Moreover, the homogenised lamina properties are found to be less sensitive to weave architecture and yarn thickness, but more so to the degree of intra-yarn fibre hybridisation, yarn width and yarn spacing. It is shown that the lamina properties can be tailored, and the micro- and meso-stress fields can be manipulated, by intra-yarn fibre hybridisation and weave architectures.

Metrological assessment of the carbon tubes behavior under thermal variation for the compensation of 3D devices

Abstract Composite materials are increasingly used in 3D metrology, especially for portable measuring devices such as articulated arm coordinate measuring machines (AACMM), 3D scanners, and ball bars. Their use is justified by their interesting mechanical properties including their low density, good rigidity, and especially their light weight, which makes them ideal for portable devices, that are meant to be often transported by the user. However, due to their complex composition, the characterization of the thermal behavior of composite materials remains complicated compared to standard materials and is nowadays an active research subject. In fact, the coefficient of thermal expansion of composite materials is dependent of the very specific composition of the composite material considered. Hence, it is function of several parameters such as the orientation of the fibers, the fiber volume fraction, the ply sequence, the cooling rate, etc. In the other hand, in 3D metrology, and especially in portable 3D metrology, determining the expansion coefficient of the different part of the measurement devices used is necessary. In fact, the portable measurement machines are often integrated and used directly on the shop floor, where the thermal variations can be important and then heavily impact the measurements results. In some cases, the lack of knowledge of the coefficient of thermal expansion of the composite materials that compose the portable measuring machine can significantly increase the measurement uncertainty.

Effects of processing temperature, pressure, and fiber volume fraction on mechanical and morphological behaviors of fully-recyclable uni-directional thermoplastic polymer-fiber-reinforced polymers

This work explores a type of composite called thermoplastic polymer-fiber-reinforced polymers (PFRPs), often referred to as self-reinforced composites (SRCs). A representative PFRP was exemplified using unidirectional (UD) ultra-high-molecular-weight polyethylene (UHMWPE) fibers embedded in a high-density polyethylene (HDPE) matrix. The effects of compression molding temperature and pressure on the mechanical and morphological behaviors of the filament-wound PFRPs with various fiber volume fractions (Vf) were experimentally investigated.The results elucidate the evolution of morphologies and tensile properties of the PFRPs due to thermal melting, fiber misalignment from pressure, and Vf-induced structural variance, which has not been comprehensively reported yet. The highest specific tensile strength and modulus of the PFRP laminae reach 600 MPa/(g/cm3) and 31 GPa/(g/cm3), respectively. These properties are comparable to glass-/aramid-fiber-reinforced polymers (GFRPs, GFRTPs, AFRPs, and AFRTPs), with PFRPs exhibiting better ductility (specific strain at peak load ≈ 4%/(g/cm3)) than other common polymer composites.The motivation for this work was the high recyclability of PFRPs, which can be recycled by melting both the fibers and the matrix, and then reshaped them for re-manufacturing composites to maximize the efficiency in material reuse. This process simplifies the implementation of closed-loop recycling, re-manufacturing, and reuse to support sustainability in composites. This work aims to contribute to advancing thermoplastic PFRPs for their potential applications in various industries.

Mechanism analysis on tensile fracture properties of heterogeneous BFLAC at cryogenic temperature: Experimental investigation and mesoscale simulation

This study aims to investigate the tensile failure behaviours and corresponding fracture mechanisms of basalt fiber reinforced lightweight-aggregate concrete (BFLAC) at various temperatures via a comprehensive cryogenic tests and mesoscale simulations, with a special focus on the quantitative effects of cryogenic temperature and fiber volume fraction. Firstly, Macro- and micro-scale split-tensile tests of BFLAC with fiber volume fractions of 0.0–0.3 % at 20∼-90 °C were conducted. Secondly, a two-steps sequentially thermo-mechanical coupled meso-scale analysis approach with explicit modelling of fibers and pore ice was developed to simulate the corresponding direct-tensile failures of BFLAC with more fiber volume fractions. The results show that as the temperature falls from 20 °C to −90 °C, the dominant action mechanism of basalt fibers changes from Mode-1 (pull-out of fibers) to Mode-2 (rupture of fibers) due to the ice formation and the interactions between meso-components. Tensile strengths of BFLAC present a significant low-temperature enhancing effect, with a maximum increase of 90 % for direct-tensile strength while 104 % for split-tensile strength. Besides, as the temperature drops, although a larger proportion of fibers are in a low bridging stress state and a smaller proportion reach yield stress for rupture, the average fiber stress increases and the utilization degree of fibers with more stresses transferred improves, which results in that the fiber reinforcement effect is strengthened. Finally, based on experimental and numerical results, the quantitative relationships between split-tensile and direct-tensile strengths at different cryogenic temperatures were given. The present research results can better understand the cryogenic mechanical properties of BFLAC, which have important reference value for its extensive promotions and applications in engineering structures exposed to extreme low-temperature environments.

A comprehensive study of carbon nanoparticle shape and orientation effects on composite elastic properties using FEA

In this study, three critical parameters that influence the effective composite properties of Carbon nanoparticles were tested and modeled using finite elements through Digimat Finite Element Analysis (FEA) software, employing representative volume elements (RVE). The primary parameters under consideration are the fiber shape, fiber orientation, and fiber volume fraction. Four of the many different shapes of Carbon nanoparticles, namely Tubes, Disk, Sphere, and Cylinder, were investigated, coupled with four distinct orientations for tubes: horizontal, aligned at 45°, random, and vertical each varying in the carbon fiber volume fraction. The material of choice was pure epoxy resin because of the nature of the bonding between its two phases and its wide range of usage. Forces were applied along the X-axis, coupled with shear in the XY plane. This study revealed that the orientation of CNTs primarily influences the Elastic Young’s modulus, whereas the size of the CNTs has the main effect on the shear modulus, followed by orientation. The horizontal CNTs demonstrated superior Young’s modulus, but the random orientation had a more pronounced impact on the shear modulus variation. Regarding the analysis of the nanoparticles shapes, the disk shape with fixed orientation revealed the highest elastic modulus, after which the cylinder shape and the sphere recorded the minimum elastic modulus among the three studied shapes.

Study on mechanical properties of natural fiber (Jute)/synthetic fiber (Glass) reinforced polymer hybrid composite by representative volume element using finite element analysis: A numerical approach and validated by experiment

The excellent mechanical strength with low weight of polymer-based composites makes them superior over conventional materials like steel and aluminum in terms of mechanical properties. Nowadays, researchers are working to develop natural fiber-based sustainable composite. Glass fiber, when combined with jute fiber, could greatly enhance the mechanical characteristics of composites; the sequence of the layers mostly determines these properties. In this study, the hybrid laminate of jute and glass fiber with resin polyester is developed with The representative volume element utilized in ANSYS. In ANSYS material design module, the 3D microstructure of composite material is created with various fiber volume fractions of glass fiber and jute fiber. After that, the effective elastic properties of hybrid jute/glass fiber and polyester as matrix, glass fiber/polyester, and jute fiber/polyester are evaluated and the simulation-based effective elastic property is validated by existing experiment value which showed good agreement. For further study, in Ansys ACP PrepPost, the composite laminate such as hybrid jute + glass fiber/polyester, glass fiber/polyester, and jute fiber/polyester is created with desired lamina thickness, stacking sequence, and fiber orientation. Thereafter, it was transferred to a static structure module to perform tensile and bending test analysis. Ansys ACP post-processing is utilized to investigate stress induced at each lamina of the composite specimen. This study revealed that by adding glass fiber to natural fiber, the mechanical performance is enhanced significantly, whereas hybrid jute + glass fiber/polyester (S2) demonstrated the highest tensile strength 259 MPa compared to other hybrid laminate composites. Astonishingly, The hybrid composite jute + glass/polyester (S2) exhibited 10 % higher bending strength than glass fiber/polyester (S1) and 64 % more than net jute fiber/polyester (S5). Additionally, S2 demonstrated 9.5 % higher shear strength compared to S1 and 64 % more than S5. This study will give a great understanding of how adding glass fiber to jute fiber, could enhance the mechanical properties, which will contribute to the design of an efficient composite part for automotive such as car interiors, car doors, trim panels, lightweight applications, and packaging industries.

Comparative Analysis of Water-Induced Response in 3D-Printed SCF/ABS Composites under Controlled Diffusion

Additive manufacturing (AM) or 3D-printing of fiber-reinforced composites (FRCs) has garnered significant interests for its versatility in creating intricate parts and rapid prototyping due to cost-effectiveness. Although short fiber-reinforced thermoplastic composites are challenging to manufacture, their mechanical properties can be easily tailored by adjusting fiber type, orientation, and volume fraction. However, void formation during printing is a key issue, impacting mechanical properties and facilitating water ingression, affecting long-term durability. This work studies water diffusion characteristics and the associated hydro-aging of 3D-printed short carbon fiber (SCF)/acrylonitrile butadiene styrene (ABS) composites with controlled water diffusion. Effects of material type (ABS and SCF/ABS), 3D-printing path (horizontal and vertical filament orientation), and diffusion surface (uni-directional and bi-directional diffusion) on water diffusion coefficient and maximum water absorption level are characterized to ensure the long-term durability of 3D-printed ABS and SCF/ABS composites. Baseline representative volume element-based finite element (RVE-FE) diffusion models were developed based on micro-computed tomography (micro-CT) image analysis to understand water diffusion characteristics. This work proves that the SCF/ABS composite is more resistive to hydro-aging than neat ABS due to the SCFs’ hydrophobic nature. SCF/ABS composites, while providing distinct advantages over pure ABS in terms of mechanical properties, could also be more effective against water environments.

Analytical simulation of the effects of local mechanisms and microstructure on the creep response of unidirectional ceramic matrix composites

A micromechanics-based method has been developed to analyze the creep response of uncoated ceramic matrix minicomposites. Although the global stress level at which the creep response is analyzed is lower than the composite proportional limit, local stresses are assumed to be high enough that localized damage is present in the composite in the form of matrix microcracks. To model the composite creep response including the effects of matrix cracking, a fiber shear lag-based methodology is employed. In this approach, stresses are assumed to vary in the fiber as a function of time and distance from the crack plane. The varying stresses are then used to compute the overall creep strain for the composite. Various assumptions regarding the level of matrix microcracking in the composite, and the level of creep in the fiber and matrix in various portions of the composite unit cell, are also examined. The creep response of the fiber is modeled using a linear Burgers model. The model is applied to a SiCf/SiC unidirectional minicomposite system. The computed creep results are compared to experimentally obtained values. The effects of the local fiber volume fraction on the overall creep response of the composite are also studied. This work will allow increased understanding of the key material damage mechanisms and load sharing that take place during creep conditions and can be expanded to provide improved analysis methods for full macrocomposites.

Electrical resistivity of eco-friendly hybrid fiber-reinforced SCC: Effect of ground granulated blast furnace slag and copper slag content as well as hooked-end fiber length

Over the last 20 years, the development of electrically conductive composites for removing snow and ice from transportation infrastructure has received exceptional traction. However, these composites need to exhibit stable electrical conductivity and high mechanical properties to be sustainable and cost-effective. Towards this goal, the article investigates the roles of ground granulated blast furnace slag (BFS) and copper slag (CS) content, in addition to hooked-end steel fiber length, on the electrical properties of eco-friendly ultra-high performance hybrid fiber-reinforced self-compacting concrete (HFR-SCC) for the first time in the literature. For this purpose, sixteen eco-friendly electrically conductive ultra-high-performance HFR-SCC were designed based on the variable parameters of four different BFS/total binder ratios (20, 40, 60, and 80 %), a CS/total fine aggregate ratio of 50 %, and two different hooked-end fiber lengths (30 and 60 mm), while all mixes used 1.75 % by volume fraction of steel fibers. After determining the workability properties (slump-flow and T500 values) of all mixes, compressive strength and electrical resistivity/conductivity tests of 90-day specimens were conducted. Additionally, environmental and economic evaluations of all mixes in terms of sustainability were performed in order to clarify the effects of the variable parameters. Taking into account the experimental results obtained, it was observed that all electrically conductive ultra-high performance HFR-SCC mixes demonstrated satisfactory workability properties, while the compressive strength values reached to impressive values of 127 MPa. The optimum BFS/total binder ratio was identified to be 40 % for higher compressive strength and conductivity of ultra-high performance HFR-SCC specimens. On the other hand, the addition of CS to the mixes resulted in an increase of almost 9 % in compressive strength compared to one without CS, while at the same time, a significant increase of approximately 363 % was observed in the electrical conductivity values of the specimens. As for the influence of different lengths of hooked steel fibers, the use of 30 mm length hooked-end steel fibers in HFR-SCC mixes performed better in terms of compressive strength, whereas 60 mm fibers performed better regarding electrical conductivity. In conclusion, this experimental work has evidenced that it is possible to develop an eco-friendly and sustainable electrically conductive ultra-high performance cementitious composite (the optimal mix compressive strength and electrical resistivity values were 127 MPa and 2242 Ω.cm, respectively) by using waste from different industries such as iron and copper. Thus, it will provide important insights for the design and application of future electrically conductive concretes, which can be an important alternative in efficient active deicing and snow-melting applications.

3D Printing and Implementation of Engineered Cementitious Composites - A Review

While 3D printing of concrete (3DCP) has gained increasing interest in the construction industry, steel reinforcement remains a significant obstacle to 3D printing (3DP) construction. To address this concern, Engineered Cementitious Composites (ECC), also recognized as Strain-Hardening Cementitious Composites (SHCC), can provide structural performance and integrity, safety, durability, and strength without steel reinforcement. The article reviews scientific works on 3DCP using ECC and proposes further investigations to lead to better development. As a result, generally, Poly-Ethylene (PE) fibers are used more frequently because of their strength. Mix design parameters have been extensively examined in relation to fresh ECC rheological characteristics. Due to the printing process, fiber orientation may affect ultimate tensile strain. As compared to casted ones with random fiber orientation, fiber orientation aligned with tensile stress resulted in a higher ultimate tensile strain. Additionally, research showed that ECC including up to 2 % fiber can be mixed, extruded, and built. Morovere, results highlighted the comparison between printed ECC containing PVA and PE fibers, the influence of mix design parameters on extrudability, and the impact of fiber length and volume fraction on strain-hardening properties. The text also covers the effects of fiber orientation and nozzle distance on tensile performance and ultimate tensile strain, as well as the anisotropic properties of 3DP-ECC. As well as this, there are some areas that require further research, such as durability and response to a variety of loading conditions, such as seismic loading.

Mechanical Characterization and Production of Various Shapes Using Continuous Carbon Fiber-Reinforced Thermoset Resin-Based 3D Printing.

Continuous carbon fiber-reinforced (CCFR) thermoset composites have received significant attention due to their excellent mechanical and thermal properties. The implementation of 3D printing introduces cost-effectiveness and design flexibility into their manufacturing processes. The light-assisted 3D printing process shows promise for manufacturing CCFR composites using low-viscosity thermoset resin, which would otherwise be unprintable. Because of the lack of shape-retaining capability, 3D printing of various shapes is challenging with low-viscosity thermoset resin. This study demonstrated an overshoot-associated algorithm for 3D printing various shapes using low-viscosity thermoset resin and continuous carbon fiber. Additionally, 3D-printed unidirectional composites were mechanically characterized. The printed specimen exhibited tensile strength of 390 ± 22 MPa and an interlaminar strength of 38 ± 1.7 MPa, with a fiber volume fraction of 15.7 ± 0.43%. Void analysis revealed that the printed specimen contained 5.5% overall voids. Moreover, the analysis showed the presence of numerous irregular cylindrical-shaped intra-tow voids, which governed the tensile properties. However, the inter-tow voids were small and spherical-shaped, governing the interlaminar shear strength. Therefore, the printed specimens showed exceptional interlaminar shear strength, and the tensile strength had the potential to increase further by improving the impregnation of polymer resin within the fiber.

Experimental study on the flexural behaviors of ECC-reinforced masonry beams with GFRP mesh

This study aims to investigate the flexural behaviors of ECC-reinforced masonry beams with GFRP mesh under various interface treatment methods. Eleven sets of ECC-reinforced masonry beams with GFRP mesh were fabricated and subjected to a four-point bending test. The effects of the fibre volume fraction and thickness of ECC, interface treatment methods, GFRP mesh strength and layers on the flexural behavior of masonry beams were investigated and analyzed, including the failure mode, crack distribution, flexural strength, and load-deflection curves. The test results revealed that a transition in the failure mode of masonry beams from brittle failure to interfacial stripping failure or ductile failure after reinforcement. Increasing the number of GFRP mesh layers, the fibre volume fraction and thickness of ECC improved the flexural performance of the masonry beams, while increasing the GFRP mesh strength had the opposite effect. Among the variables, the interface treatment method exerted the greatest influence on the flexural performance of the masonry beams. The masonry beams treated with a bolt interface exhibited the best flexural performance, with flexural toughness and ultimate deflection increasing by 1.69 times and 0.32 times, respectively. Furthermore, the flexural performance of the masonry beams reinforced with a 15 mm thick ECC and single-layer GFRP mesh demonstrated similar reinforcement effects to the masonry beams reinforced with a 20 mm thick ECC, while reducing costs by 23 %. Based on the existing codes governing the calculation method of flexural strength and considering the influence of various factors, a calculation model for the flexural strength of ECC-reinforced masonry beams with GFRP mesh was established.

CRFP Mechanical Properties—Stated Values Versus Experimental Data

Abstract This study thoroughly examines the mechanical properties of carbon fiber-reinforced polymers (CFRPs), motivated by the critical need for accurate composite property data in investigating fracture control measures for structures subjected to barely visible impact damage. We compared experimental results with manufacturer-stated values, focusing on discrepancies in fiber volume fraction and its impact on elastic modulus. Experimental findings showed an increase in elastic modulus to 190 GPa for 0 deg orientation samples, compared to the manufacturer's stated value of 159.27 GPa. The recalculated fiber volume fraction increased from the expected 57% to an actual value of 60.96%. This increase in fiber content, determined through the Voigt modulus equation and corroborated by SEM image analysis, directly contributed to the observed variations in elastic modulus. Tension tests at 0 deg and 90 deg angles exhibited average percentage errors of 14.83% and 11.57%, respectively, while compression tests at 0 deg displayed a deviation of approximately −13.92% after adjusting for values beyond 0.05% compressive strain. The study underscores the critical impact of fiber volume fraction on CFRP properties and highlights the importance of precise empirical evaluation for accurate CFRP characterization in applications such as aerospace engineering.

Development of a 3D printer for long fiber-reinforced plastic and evaluation of the mechanical properties of printed parts

The field of three-dimensional (3D) printing, a technology that allows low-cost printing of complex 3D shapes with a high degree of modeling freedom, has exhibited significant growth over the last few years. This paper proposes a new 3D printing mechanism for long fiber-reinforced plastic as part of an effort to realize 3D-printed shapes with favorable mechanical properties and describes how prototype parts were printed using the new method. We also devise a method for modifying the fiber surface and other techniques for improving adhesion of fibers and UV resin. Mechanical testing of prototype parts printed using the proposed method indicates that the parts exhibit excellent mechanical properties as a result of filling with long fibers, indicating that the method yields a material with few voids and a high fiber volume fraction.

A multiaxial multiscale compressive thermo-mechanical damage model for Fiber Reinforced Cementitious Composites (FRCC)

In the current study, a multiaxial multiscale compressive stress-strain model for Fiber Reinforced Cementitious Composites (FRCC) was innovatively developed. The proposed model was on the basis of the theory of thermodynamics, multiscale theory and internal variable theory. The free energy function and dissipation function were established to characterize the elastic and plastic deformation of FRCC, respectively. The multiscale behaviors of FRCC in meso-scale and macro-scale was taken into account. In meso-scale, the energy dissipation functions of fiber in tension and bond-slip deformation in the interface transition zone (ITZ) were established. The resistance to cracking of cementitious matrix through the fiber bond stress were taken into account. In macro-scale, the thermo-mechanical coupling contributions of plastic damage, thermal damage, yield surface and hardening evolution were creatively considered in the potential function within thermodynamics framework. The influence of types and volume fractions of fibers on the reinforcement mechanism was discussed. When the temperature is higher than the melting point of fiber, the fiber influence coefficients was employed. The sensitivity of yield surface was discussed. The numerical predictions of this developed model were carried out for validation. The nonlinear stress-strain responses of concrete were accurately captured at temperatures ranges from 20 °C to 800 °C compared with the experimental data, which indicates the accuracy and applicability of the proposed model.

A material-structure coupled design method to study the impact response of CFRP apron board for railway vehicle

It is of great significance to improve the design efficiency and guide material selection for carbon fiber reinforced polymer (CFRP) vehicle structures, thereby, contributing to lightweight high-speed trains. This study proposes a material-structure integrated design approach that bridges the computational relationship between design variables across multiple scales and the impact responses of CFRP vehicle structures. Computational models are constructed at the micro-scale, meso-scale, and macro-scale to capture the multi-scale characteristics of the CFRP structures. At micro-scale, finite element simulations are used to determine the effective properties of fiber bundles using a representative volume element (RVE) model. This information is then transferred to the meso-scale RVE model to calculate the homogenized mechanical properties of the lamina. Finally, a macro-scale model is established to investigate the damage mechanisms and impact resistance of the CFRP apron board against the projectile impact. The influences of design variables, such as fiber type and volume fraction, are analyzed to provide further insights into the design of CFRP apron boards.

Material Selection of Natural Fibre Composite Webbing Sling Using Rule of Mixture

Natural fibre composites have grown in popularity as environmental concerns and knowledge about using eco-friendly materials versus synthetic materials. Furthermore, due to their low density and high strength, natural fibres are suitable for use as lightweight composite and reinforcing materials. Webbing slings are commonly used in many industries to lift loads and are typically made of synthetic fibres such as nylon and polyester. This study analysed the physical and mechanical properties, such as density, tensile strength, and Young’s modulus of natural fibre composites. Bananas, pineapple, and jute with polymer matrices such as polypropylene (PP) and epoxy (EP) were used as alternative natural fibre composites for webbing sling application. Furthermore, descriptive statistical analysis was done to summarise the secondary data from the previous study of the physical and mechanical properties of natural fibre and polymer matrix. The rule of mixture (ROM) is used to identify the optimum fibre loading for manufacturing the webbing sling. This study’s volume fractions of fibre were 10%, 30%, and 50%. Using the ROM equation, the results revealed that the higher fibre loading of up to 50% could increase the mechanical properties such as tensile strength and Young’s modulus. Based on the results, pineapple/epoxy composite was the best material to manufacture the webbing sling and complied with the requirements of Product Design Specifications of polyester webbing sling compared to banana and jute composites.

Multiscale damage and low-velocity impact study of three-dimensional woven composites

Three-dimensional woven composites address the limitation of weak interlaminar strength found in traditional laminated composites and offer superior resistance to out-of-plane impact. However, the complex material composition and structural intricacies necessitate investigation into their damage mechanisms. This study introduces novel and reliable microscale and mesoscale Representative Volume Element (RVE) models for three-dimensional woven composites, developed through advanced CT scanning and comprehensive multi-directional tensile and shear experiments. The research explores the impact of fiber volume fraction on yarn mechanical properties using the microscale RVE model, yielding precise macroscale homogenization parameters through the mesoscale RVE model. Furthermore, a macro-meso model tailored for low-velocity impact scenarios is established, significantly enhancing computational efficiency without compromising accuracy, thus providing support for further research on the impact properties of three-dimensional woven composites.