Roving Glass Research Articles

Mechanical Analysis and Simulation of Wood Textile Composites

Wood Textile Composites (WTCs) represent a new and innovative class of materials in the field of natural fiber composites. Consisting of fabrics made from willow wood strips (Salix americana) and polypropylene (PP), this material appears to be particularly suitable for structural applications in lightweight construction. Since the threads of the fabric are significantly oversized compared to classic carbon or glass rovings, fundamental knowledge of the mechanical properties of the material is required. The aim of this study was to investigate whether WTCs exhibit classic behavior in terms of fiber composite theory and to classify them in relation to comparable composite materials. It was shown that WTCs meet all the necessary conditions for fiber-reinforced composites in tensile, bending, and compression tests and can be classified as natural-fiber-reinforced polypropylene composites. In addition, it was investigated whether delamination between the fiber and matrix can be simulated by using experimentally determined mechanical data as input. Using finite element analysis (FEA), it was shown that the shear stress components of a stress tensor in the area of the interface between the fiber and matrix are responsible for delamination in the composite material. It was also shown that the resistance to shear stress depends on the geometric conditions of the reinforcing fabric.

Hybridization of woven kenaf and unidirectional glass fibre roving for unsaturated polyester composite

This is a study on the mechanical properties of kenaf/glass-reinforced polyester composites intended for use in structural profiles with a wall thickness by max. 6 mm. Mechanical properties such as tensile, compression, bending and interlaminar shear stress were investigated by comparing the hybrid variants with the pure fibreglass variant. According to the study, woven kenaf/unidirectional glass roving (WK/UG) alternate recorded the highest tensile properties among hybrid samples. It demonstrated a decrement of about 8.2% of the tensile strength (404.54 MPa) and 10.7% of tensile modulus (24.54 GPa) compared to conventional fibreglass samples. Alternating WK/UG samples demonstrated higher compressive strength (417.15 MPa) compared to other hybrid specimens, recording a slight decrease at 6.09% compared to pure fibreglass composites. The highest bending properties were also observed in hybrid alternate WK/UG samples among other hybrid laminates with only a decrement of 4.13% in modulus of rupture (456.33 MPa) and 1.9% in modulus of elasticity (14.49 GPa) when compared to the control specimen. The ILSS of hybrid composites 2WK/3UG/2WK (30.97 MPa) and WK/UG alternate (34.90 MPa) showed good agreement with the pure fibreglass (42.33 MPa) composites. Using SEM images, tensile fractured specimens were examined to comprehend composites’ failure mechanism and interfacial adhesion. Overall, woven kenaf/unidirectional glass roving alternate sequence is chosen as a potential alternative in developing structural profiles for moderate load-bearing structural applications. In contrast, 3WK/UG/3WK with a higher kenaf to glass ratio demonstrate potential in low load-bearing structural profile applications.Graphical abstract

Empirical investigation of temperature effects on the mechanical properties of glass textile reinforced concrete

Textile Reinforced Concrete (TRC) is an innovative composite material that combines fine-grained concrete with textile fibers, resulting in improved mechanical properties for building materials. This research focuses on the impact of elevated temperatures on the mechanical characteristics of Glass TRC. Specifically, it investigates the tensile strength and bonding between glass rovings and fine-grained concrete. The study includes pullout tests on bonding TRC specimens and uniaxial tensile tests on tensile specimens exposed to temperatures of 30°C, 80°C, 150°C, and 200°C. The experimental results reveal that at 30 °C, the fiberglass mesh exhibits strong adhesion to fine-grained concrete, with an average bonding strength of 23.2 N/mm and an anchor length of approximately 120 mm. However, as the temperature increased to 150 °C and 200 °C, the bonding strength decreased by 33.4% and 46.2%, respectively. The tensile strength of TRC was 1470 MPa at 30 °C, but it decreased by 21.9% and 30.4% at temperatures of 150ºC and 200ºC.

Технология изготовления образцов из полимерных композиционных материалов

The article considers the materials, composition and methods of manufacturing samples from polymer composite materials (PCM). There is presented the method of testing samples of PCM for mechanical properties. For testing, plates were made from which samples from PCM were cut, based on glass roving, glass wool and polyester resin with the addition of a hardener. Using mechanical tests, the influence of the quantitative ratio of layers of glass wool and roving fiberglass has been determined when testing samples for three-point bending, stretching and compression. A scheme of structural reinforcement of PCM plates is given, graphs of the average values of breaking loads and ultimate strengths when testing samples for three-point bending, dependences of average values of breaking loads and ultimate strengths when testing samples for tension and compression are illustrated. Comparative analysis of the average values of the tensile strength of the samples during the compression test has been carried out. As a result of processing the data obtained during the study, it was found that with an increased number of layers of roving glass in the PCM composition increases the destructive load and tensile strength, compression, but the values of the applied load of PCM samples decrease during three-point bending tests. The experimental data obtained from the test results of PCM samples are the main indicators of the mechanical properties of PCM with various reinforcement schemes for their use in ship hull structures, in particular as a material for ship tanks.

Investigation of properties of mineral, chemical and vegetable fibers

Comparative tests have been carried out under the same conditions of fibers: mineral (basalt, glass), carbon, chemical (polycaproamide, polyacrylonitrile, viscose fiber) and vegetable (bast fibers of flax, hemp, nettle). The diameter of the monofilament, linear density, breaking load of the roving (fiber bundle) and microplastics, specific breaking load and gain factor were evaluated. Glass and basalt fibers have the highest linear density 1200—2500 tex, carbon fibers — 378, chemical fibers — 183 tex (except PAN — 826 tex), bast vegetable fibers have 440—630 tex. The specific breaking load for glass roving and basalt roving is comparable: 240—264 mN / tex, for carbon — the highest is 597 mN / tex, the gain factor is 2—2.25. For chemical fibers, the specific breaking load is 282—323 mN / tex (for viscose 92 mN / tex), the gain factor is 0.5—0.9. Concerning vegetable fibers, the highest breaking load of flax and hemp fibers is 93—102 mN / tex, exceeds the viscose fiber, the gain factor is 1.6 for hemp and 4.39 for flax. Nettle fibers have the lowest results among plant fibers.

Comparison of pull-out behavior of glass, basalt, and carbon rovings embedded in fine-grain concrete and geopolymer

Abstract In this work, we studied the pull-out behavior of glass, basalt, and carbon rovings embedded in fine-grain concrete and geopolymer. Smooth rovings from the bobbin and coated rovings extracted from the fabric were both studied. A matrix made of fine-grained concrete and geopolymer was used to determine the interaction between roving and matrix during pull-out. The use of these matrices provides an economical consumption of concrete used in building structures. In addition, the bonding effect between coated roving and matrix was also investigated. As a result, it was observed that the bonding strength in a matrix made of fine-grained concrete is higher than that of a geopolymer. Smooth roving exhibited a minimal bonding characteristic irrespective of the matrix. The best anchoring is achieved by the coated roving extracted from the fabric and the strength characteristics of the roving itself are not critical.

In Situ Deformation Monitoring of 3D Woven Composite T-Profile Using MXene Nanoparticles.

The aim of this study was to develop a process-efficient smart three-dimensional (3D) woven composite T-profile by depositing MXene nanoparticles at the junction for sensing damage and deformation at the junction. Such smart composites could find application in the online health monitoring of complex-shaped parts. The composites were manufactured by infusing epoxy resin in a single-layer fabric T-profile preform, woven in folded form on a dobby shuttle loom using 300 tex glass roving. The chemically etched Ti3C2Tz MXene nanoparticles were dispersed in deionised water and 10 layers were sprayed at the junction of the composite to form a conductive coating. The MXene-coated composite T-profile specimens were subjected to tensile and fatigue loading to study the electromechanical response of the MXene coating to applied displacement. The results showed that the MXene coating was able to sense the sample deformation till ultimate failure of the composite. The MXene coating was also able to effectively sense the tensile–tensile fatigue loading, carried out at 2000 cycles and 4000 cycles for a 50 N–0.5 Hz and a 100 N–1 Hz load–frequency combination, respectively, while being sensitive to the overall deformation of the composite. The smart complex-shaped composites developed in this work were capable of monitoring their health under tensile and fatigue loading in real time.

A Study on Chemical Ageing of Composite Ribbed GFRP Bars under Load

Here we explored the chemical durability of glass fiber-reinforced polymer (GFRP) bars under load. Three batches of ribbed GFRP bar specimens were fabricated using binder matrices: ED-22+isomethyltetrahydrophthalic anhydride (iso-MTGFA), ED-22+Ethal-450 and NPPN-631+ iso-MTGFA. As the reinforcing filler, we used an EC17 glass roving (for all the specimen batches). The specimens of each batch were aged in a 1 N alkaline NaOH solution at 60 °C for 2000 hrs. The ageing was performed under a 300 MPa load (30% of the failure stress). The tensile strength of the specimens from each batch following ageing was measured. The tensile test results demonstrated that that the strength loss of the specimens following chemical ageing was 58.9% for batch 1 based on ED-22+iso-MTGFA, 6.6% for batch 2 based on ED-22+Ethal-450, and 33.6% for batch 3 based on NPPN-631 + iso-MTGFA. The specimens of batch 2 based on ED-22+Ethal-450 exhibited the greatest resistance to the NaOH alkaline solution (a strength loss of 6.6%).

Analysis of reinforcement efficiency and microscopic characterization of glass and carbon roving geometry in prestressed concrete composites

In this work, the reinforcement efficiency of concrete composites prestressed with glass and carbon rovings was studied. Prestressed concrete composites samples were prepared at a prestress level one-third the maximum tensile strength of the roving. The flexural properties of the manufactured composites were determined using a four-point bending test. Additionally, changes in the cross-sectional shape of the reinforcing rovings in the initial and prestressed states were analyzed using CT scanning and optical microscopy. The results showed that prestressing significantly affected the flexural properties of the concrete composites. Thus, the limit of proportionality increased by 1.26 and 1.85 for a composite reinforced with glass and carbon roving, respectively. The maximum flexural strength increased by approximately 1.2 times for both reinforcing rovings. The change in the cross-sectional shape of the reinforcing roving during prestressing enhances the efficiency of prestressed concrete composites.

Enhancement of mechanical behavior of resin matrices and fiber reinforced polymer composites by incorporation of multi-wall carbon nanotubes

Herein, to enhance the toughness of resins and tensile strength of fiber-reinforced polymers (FRPs), multi-wall carbon nanotubes (MWCNTs) were incorporated as a toughening material into resin matrices. The effects of the MWCNT addition on the fracture toughness (KIC) and mechanical properties of epoxy and vinyl ester resins, and the tensile strength (σr) and stiffness of impregnated basalt, carbon, and glass fiber rovings were systematically examined. The enhancement mechanism was studied by scanning electron microscopy (SEM). The enhancement in the tensile strength of the FRPs was predicted. The results showed that as compared to pure epoxy resin, the 0.3 wt% MWCNT-modified epoxy resin exhibited elevated KIC, tensile strength (σt), flexural strength (σf), and impact strength (αcU). Similar improvements were discovered for the MWCNT-modified vinyl ester resins. Concentrated tortuous textures due to the bonding and bridging effects of MWCNTs were observed on the fracture surface by SEM. The σr of the basalt, carbon, and glass rovings obviously increased with the addition of MWCNTs, owing to the combined action of restricted crack propagation and the promoted co-stress of fibers. Additionally, the σr of MWCNT-modified basalt and carbon rovings exhibited a lower dispersion, resulting in a higher guaranteed strength. The modification method proposed above can effectively improve the mechanical properties and design strength of FRP.

Numerical modeling of the mechanical behavior of textile structures on the meso‐scale for forming process simulations of composite 3D preforms

AbstractThe models for textile structures based on the Finite Element Method (FEM) are diverse. In general, they can be divided into three groups based on their length scale: macro‐, meso‐, and micro‐scale models. The macro‐scale models are the simplest approach and require the least computational cost. On the contrary, the micro‐scale models are the most realistic and complex, thus involving extremely high computational costs. The meso‐scale models stand in the middle with sufficient representation degree at a reasonable computational cost. Every group of models has its own advantageous application field. For the forming process of 3D preforms, macro‐scale models have been widely used. As computational costs drop over time, meso‐scale models become more and more favorable. Hence, research efforts increasingly focus on meso‐scale models. In this paper, the modeling methods of FEM meso‐scale models for plain woven fabric made of glass roving and biaxial reinforced weft‐knitted fabric made of carbon fiber/polyamide 6.6 hybrid yarns are introduced. The experimental tests are used to characterize the mechanical properties of the yarns and fabrics. Different modeling methods for the geometries of each type of fabric are described. The mechanical behavior of the models is calibrated and validated with the help of a series of test simulations. Examples for the usage of the introduced models are presented.

Improving the shear strength of bolted connections in pultruded GFRP using glass fiber sheets

Pultruded Glass Fiber Reinforced Polymers (PGFRPs) have been increasingly used in the field of engineering construction. In civil engineering structures, mechanical connections such as bolted connections are widely used because they are an easy way to connect the members. However, this kind of connection for PGFRP has low shear strength when the main part of the PGFRPs features unidirectional glass roving, and the shear strength of this part is determined by the shear strength of the matrix. This problem reduces the mechanical performance of the connections. In this study, the strengthening effects of three types of glass fiber sheets (GFSs) (0°/90°, ±45°, and a chopped strand mat (CSM)) on PGFRP connections were experimentally investigated under tensile loads. Based on the experimental results, GFSs could remarkably improve the ultimate loads and stiffness of PGFRP connections. Moreover, simple formulas were proposed to evaluate the ultimate loads of single PGFRP-bolted connection reinforced by multiaxial GFSs.

Tensile Properties of Glass Roving and Hybrid Tapes

Among many other materials for the reinforcement of composites, technical fabrics are increasingly being used, especially from glass tows, which have good mechanical properties. In this paper, glass fiber based tapes containing special types of resins, in pre-condensate form with application in technology of composites preparation by precise winding is prepared. Also, the selected suitable resin was loaded by suitable types of nanoparticles for enhancing mechanical properties. The tensile properties of the tapes made from glass were investigated. Measurements of resultant stabilized hybrid composite tapes (SHCT) were focused on the breaking force, deformation at break and initial modulus. It was found that the durability of the tapes was sufficient for long term storing. The main benefit was avoiding of resin penetration into winded structure which is due to tight arrangements of fibrous phase which is very complicated. The results show that SHCT can be stored and used after a longer period of time.

Estimation of Strength of Composites Reinforced with Woven Preform

Bending strength of composites produced by using two layers of woven preforms from glass and flax rovings is studied experimentally. Statistically significant models describing the process of deformation of the studied composite samples are constructed. A method of nondestructive monitoring is proposed for estimating strength of two-layer composites produced by using two-layer woven preforms.

Verification of FEM modelling of composite materials based on the results of static strength test

The article presents the verification of FEM modelling of composite materials based on the results of static strength test. The aim of the work was to examine whether the applied modelling of composite materials is correct and verify it with finite element method (FEM). The composite structure of the PW-6U glider was used as a model. In the program the numerical model (geometry and finite element mesh) of the glider’s wing was created. The wing is made of glass fabrics and a spar with flanges with a glass roving. The composite structure of the wing, including composition, layout and thickness of laminate layers, fiber arrangement was exactly modelled in the program and then subjected to loads. Having the measurements from the static strength tests of the glider, the numerical results were compared with the experimental results. Thanks to the applied modelling, the obtained numerical results were satisfactory and very close to the experimental results from the structural static tests of the glider. Therefore, it can be concluded that the conducted verification of FEM modelling of composite materials is correct. Nowadays application of composite materials is increasingly expanding. Therefore, the modelling of composites becomes a significant issue. FEM modeling allows verification of the structure. At the stage of modelling modifications can be implemented and thus time and costs associated with subsequent changes in the production process may be saved. This is a very good solution which already at the design stage of the structure allows examination of its strength.

TECHNOLOGY OF MANUFACTURING COMPOSITE VALVES OF A PERIODIC PROFILE

The widespread use of composites was restrained, mainly due to the lack of industrial technology that would allow mass production of products with a complex configuration with the required dimensional accuracy.The issues of creating a technology for the production of glass and basalt plastic reinforcement of a periodic profile for the reinforcement of cement concrete and the determination of the chemical resistance of composite reinforcement are considered.The technology was based on the formation of a reinforcing bar by pulling method - a technology that combines the broaching of pre-impregnated with a binder of continuous reinforcing fiber with its winding threads of glass, basalt or carbon fiber in a single technological non-filter process. The technology for producing a rebar by the method of non-filtering rolltrusion is a practically waste-free and high-performance process due to its continuity. The principal differences of the proposed reinforcement is the presence throughout the entire length of the main (power) cylindrical composite rod and standing anchoring - a spirally deformed layer on the surface of the reinforcing rod of the same composite, but with a smaller percentage of reinforcing filler.It has been established that composite reinforcement can be used for the reinforcement of concrete exposed to acidic and alkaline corrosive media, including concrete, used for the construction of sewage treatment plants.The research results form the basis for the development of guidelines for the design and manufacture of concrete structures with non-metallic composite reinforcement based on basalt and glass roving.

Fiberglass Coating Technology for the Production of Water Attractions

The properties of reinforced polymer composite materials based on different types of polymer binders and glass fiber fillers were studied. The recipe and production technology were developed for articles made from fiberglass. This technology is based on a spraying assembly from the Glas Craft Company, combined with a chopper—a high-output cutting machine from the Greco Company. It is shown that the spray technology for producing from fiberglass, based on polyester resins and glass roving, large-size modules of water slides and other attractions for pools and water parks is technically sound and economically efficient.

Study of Elastic-Strength Properties of Basalt-, Glass-Filled Plastics with Different Winding Schemes

Samples of models of OHL supports based on basaltic and glass roving in the form of tubes with five different winding schemes were fabricated: longitudinal-transverse, spiral-longitudinal, spiral-longitudinal-transverse, and spiral with angle 30 and 60° with respect to the axis of the mandrel. The elastic-strength properties were investigated in tests by transverse bending and it was shown that the largest values of the elastic modulus obtain with the longitudinal-transverse winding scheme and the smallest values with spiral winding at angle 60° with respect to the axis. The elastic modulus of the basalt-plastic tubes is someone smaller than that of glass-plastic tubes, which can be explained by the lower linear density and more uniform packing of the used glass roving.

Development of shape memory alloy hybrid yarns for adaptive fiber-reinforced plastics

The application of shape memory alloys (SMAs) for the development of adaptive fiber-reinforced plastics has been expanding steadily in recent years. In order to prevent matrix damage and optimize the actuating potential of SMAs during the process of thermally induced activation, a barrier layer between SMAs and the matrix of fiber-reinforced plastics is required. This article approaches the textile technological development of SMA hybrid yarns as a core–sheath structure using friction spinning technology, whereby the SMA serves as the core. Four types of hybrid yarns are produced by varying the number of process stages from one to three, as well as the core and sheath materials. The decoupling of the SMA from fiber-reinforced plastics is crucial for optimizing the actuating potential of SMA, thus it is tested by means of the pull-out test. Although the material loss coefficient increases by raising the number of process stages, the three-stage processing of SMA hybrid yarn with an additional glass roving is found to be the most suitable variation for decoupling SMA from the matrix of fiber-reinforced plastics.

X-ray computed tomography characterization of manufacturing induced defects in a glass/polyester pultruded profile

Critical assessment of the internal geometry after manufacturing of fiber reinforced polymer composites is essential for developing more reliable and robust production. In the present work, manufacturing induced defects such as fiber misalignment and porosity in a glass/polyester pultruded composite profile are evaluated. The internal geometry of the composite is characterized by X-ray micro-computed tomography (micro-CT) and analyzed using the VoxTex software which allows validated and detailed characterization of the internal geometry. Resin rich areas are observed in between the glass rovings at which the unidirectional fibers are misaligned with respect to the desired pulling direction. Results show that the misalignment in in-plane fiber orientation is more severe (30–40°) than the out-plane fiber orientation (10–20°). Two different types of porosities are quantified: the first one is discontinuous and located inside the resin rich areas; the second one is more severe and continuously located between the glass rovings. The area of the total continuous porosity is estimated approximately as 0.212–0.246 mm2 per unit length in the pulling direction. The fiber misalignments and resin rich areas cause 15–20% reduction in the studied part stiffness in the longitudinal direction.