Glass Fibre Reinforced Research Articles

Mechanical and Tribological Performances of Thermoplastic Polymers Reinforced with Glass Fibres at Variable Fibre Volume Fractions.

High wear rates and frictional coefficients have always been the primary reasons for limiting the service life of critical elements such as pumps, couplings, bushings, bearings and gears. The premature and erratic failures are costing the industries extensive amounts of money every year. Additionally, under severe service conditions, the wear resistance requirements are higher, which greatly hinders the application of neat thermoplastics in different sectors. Hence, it is vital to enhance the tribological characteristics of thermoplastics. The mechanical and tribological properties of Polyamide 6, Thermoplastic Polyurethane, and glass fibre reinforced (GFR) Polyadmide 6 Composites of variable fibre volume fractions were investigated. Pin specimens of Polyamide 6 reinforced with (25%, 33%, and 50%) by volume of fibres were fabricated by an injection moulding process. The specimens were tested for tensile, compression, hardness, and wear under dry abrasive conditions using a pin-on-disc setup. Furthermore, the samples were scanned using micro-computed tomography (micro-CT), and the worn-out samples were analysed using field emission scanning electron microscopy. The experimental results showed that the fibre volume fraction was inversely proportional to the wear resistance of the prepared composite materials. This research will enable the industry partners to supply cutting-edge technologies to the global oil and gas industry that not only minimizes the well running cost but also improves the well resilience.

Residual Durability Performance of Glass Fiber Reinforced Concrete Damaged by Compressive Stress Loads

Concrete is exposed to a variety of stresses throughout its service life, which can result in cracks and damage. The use of fibers in concrete mixtures is known to improve the mechanical and durability properties of the concrete. In this study, glass fiber-reinforced concrete cube specimens were produced and stressed at 70 and 90 percent of their maximum compressive strength. The effects of stress loading-induced cracks and glass fiber reinforcements on mechanical and durability properties of concrete specimens were investigated using UPV, capillary water absorption, acid effect, and high-temperature effect tests. Glass fibers increased compressive strength and reduced water absorption in specimens that were not stressed. On the other hand, glass fibers increased the durability of stressed specimens at both degrees of compressive load stress. The bridging effects of glass fibers reduced crack creation, resulting in improved UPV test results. Glass fibers did not dissolve in acid solution due to their chemical resistance, resulting in less weight loss and higher compressive strength in concrete specimens. In the high-temperature effect tests, decreasing compressive strength values were observed as the stress load and temperature levels increased. However, such reductions were lower for glass fiber reinforced concrete than for control concrete without glass fiber. As a result of the present findings, glass fiber reinforcements prevent stress-induced cracks, making the concrete more durable and stronger against external forces.

Dynamic failure of 3D printed negative-stiffness meta-sandwich structures under repeated impact loadings

Achieving superior reusable energy absorption and mitigation properties under repeated impact loadings with high strain rates, yet maintaining the lightweight design feature, is still a challenge for thin-walled structure design. In this work, combined with the concept of mechanical metamaterial, several kinds of negative-stiffness meta-sandwich structures (NSMSs) are developed and their dynamic responses under repeated high strain-rate impacts are systematically investigated. The 3D printing technique of selective laser sintering (SLS) is applied to fabricate the composite NSMSs with glass fiber reinforced (GFR) Nylon. The bistability of the double curved-beam topology and the remarkable impact resistance to the repeated impact loadings are theoretically, numerically, and experimentally analyzed. An analytical model based on the Gibson-Ashby framework is presented to predict the mechanical behavior of NSMSs, and a series of evaluation indicators are developed to quantitatively describe the energy absorption performance. Compared with a conventional honeycomb structure, the unique layer-by-layer failure mode for NSMSs, leading to a significant improvement in the capacity of multiple-impact resistance, is unambiguously demonstrated. This new type of artificial structure paves a feasible way to achieve superior energy absorption and impact resistance features under repeated impacts.

Relation between injection molding conditions, fiber length and mechanical properties for highly reinforced long fiber polypropylene

AbstractA complete study on the relation between the injection molding parameters and the resulting fiber length, orientation and mechanical properties is presented for highly reinforced long fiber thermoplastic (LFT) polypropylene (PP). It has been found that the longest fibers obtained are the ones processed with the lowest backpressure and the highest screw speed. The backpressure gains importance over screw speed when the amount of glass fiber reinforcement increases, contrary to what was found for less reinforced thermoplastics. The injection speed does not influence the fiber breakage phenomena, while it has great importance in fiber orientation and thus on the tensile strength, especially when the weight fiber average length is below 1000 μm. When this average is over 1000 μm, fibers begin to weave a mesh that thickens the core region and hinds its orientation, reducing the tensile strength but improving impact resistance.

Investigation of quasi-static indentation on sandwich structure with GFRP face sheets and PLA bio-inspired core: Numerical and experimental study

Composite materials incorporated in naval, aerospace, and automobile structures are exposed to unforeseen damages, which seriously damage their mechanical performance. In particular, the existence of hardly visual impairment on the in-service composite structures is a critical issue that highlights the severity of structural safety in an aircraft. The ability of these materials to sustain multiple impacts requires an understanding of the impact energy absorption to improve the material’s damage tolerance. The present study investigates the energy absorption, load response, failure modes, and damage mechanics under the quasi-static indentation of a sandwich structure. The structure comprises bio-inspired Poly-lactic Acid (PLA) core and Glass Fibre Reinforced Polymer (GFRP) laminates, used in real naval and aeronautical structures, under repeated low-velocity impact with reduced energies and quasi-static indentation. In addition, a lightweight sandwich structure’s damage performance is greatly influenced by its core geometry. Therefore, choosing an appropriate core structure is critical. A Numerical model is developed for the composite structure under quasi-static indentation loads, considering suitable material properties and damage models for the core and face sheets. These results are then compared with the experimental investigation. The load–displacement response and the energy absorption characteristics of the sandwich structure showed good agreement for the experimental and numerical analysis results.

The Effect of Powder and Emulsion Binders on the Tribological Properties of Particulate Filled Glass Fiber Reinforced Polymer Composites.

Investigations into polymer composites are mainly focused on properties dependent on glass fiber reinforcement and particulate fillers. In the present study, the effect of the binder was examined. The specimens were produced with two types of epoxy resin, with similar numbers of glass mat layers and similar proportions of quartz powder added. However, one group was fabricated with an emulsion binder in the glass mats and another group with a powder binder. Attention was concentrated on the tribological properties of the as-prepared composites, though their strength was examined as well. The hardness of the Sikafloor matrix was found to be much more sensitive to the applied binder than that of the MC-DUR matrix. No direct correlation between the microhardness and the specific wear rate was observed and increasing the particulate filler proportion did not cause a direct increase of the specific wear rate. In particular, the highest specific wear rate, around 350 J/g, was reached for both matrices with a 1% quartz addition when the emulsion binder was applied, while in the case of the powder binder it was with 6% quartz with the MC-DUR matrix, and there was no quartz addition with the Sikafloor matrix. The highest microhardness, HV0.5 = 25, in turn, was reached for the mats with the emulsion binder in the Sikafloor matrix with an addition of 10% quartz powder, while the highest friction coefficient was exhibited in the composite with the MC-DUR matrix, when 1% of the quartz powder and the emulsion binder were applied.

Dynamic mechanical analysis of glass fiber reinforced epoxy filled nanoclay hybrid composites

In this work, dynamic mechanical analysis (DMA) of hybrid composite material made up of glass fiber reinforced epoxy polymer filled with nanoclay particles is investigated. The effect of fiber architecture, orientation and concentration on DMA properties of hybrids is studied. Three different types of glass fiber mats were chosen, namely, unidirectional glass fiber (UD-GF), woven glass fiber (W-GF) and chopped strand mat glass fiber (CSM-GF) and they were individually reinforced in epoxy polymer matrix at three different varying concentration (25 wt%, 50 wt% and 75 wt%). The nanoclay particles were added as filler material and its concentration was varied from 1 to 5 wt% in all the hybrid series. In UD-GF reinforced hybrid, the fibers are oriented at different orientation (0° to 90°) with respect to loading condition and the DMA properties was evaluated. The structure and fiber–matrix interface morphologies were examined by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) analysis. The effect of interface properties on DMA properties is studied by theoretical and Cole-cole methods. The result shows that the DMA properties such as storage module, glass transition temperature (Tg) and Tanδ curve (peak and width) were affected by both the concentration and morphology of glass fiber reinforcement and the nanoclay fillers. In general, nanoclay reinforcement in glass fiber reinforced epoxy composites improves the hybridization effect and positively improves the DMA properties.

Study of implementation the tensile data of the glass fiber reinforced polyamide into the finite element analyses

The increased demand for newly developed products and the necessity of using plastic materials progressively more, requires a faster way of understanding how the product made of reinforced plastics will behave under certain loads and environmental conditions.By using the finite element method, we can evaluate the performance of one product that is made from reinforced glass fiber. For this purpose, we have evaluated the stress–strain data of two different materials – the same type of polyamide with different reinforcement grades – and included the results in a finite element analysis where the initial stress–strain results were compared to the one obtained in the test.The analysis’ results show, that for the same level of displacement imposed in the finite element method, we are obtaining the same level of stress as the one obtained in the tensile test.

Mechanical behaviour evaluation of glass fiber and chicken feather hybrid composite

Composites are emerging as new trends in materials industry. A demand in new range of material technology is essential in the present innovative timeline. An attempt is made to fabricate a hybrid composite of glass fiber (GF) as reinforcements, chicken feather (CF) powder as filler and epoxy as matrix material. Composites are manufactured by hand lay-up method. Mechanical behavior are identified through tensile (σT), compressive stress(σC) & Rockwell hardness (HRL) tests. CF are preferred as natural filler material and its inclusion with GF reinforcement gives σT = 180.45 Mpa, σC = 79.5 Mpa, & 72 HRL which shows promising values for moderate load resisting applications. Since CF is combined with GF, the test results reduce compared with composite without CF. This work depicts the effect of CF combination with reinforcement material GF in composites.

Crack resistance of bent concrete structures with fiberglass reinforcement

This article presents experimental data on the appearance and development of normal and oblique cracks in relation to the longitudinal axis of the element under the influence of transverse loads on bending concrete beams equipped with shishaplastic Composite fittings made of ordinary heavy concrete.

Performance of hybrid glass/steel fibre self-compacting concrete beams under static flexural loading

In this paper, it is proposed to study the static flexural performance of hybrid (glass and steel) fiber reinforced M30 grade self-compacting concrete (SCC) beams made with glass fiber reinforcement polymer (GFRP) re-bars. Nan Su mix design approach is adopted to develop the M30 grade plain SCC (PSCC) mixes. Glass fibre SCC (GFRSCC), steel fibre SCC (GFRSCC) and hybrid fibre SCC (HFRSCC) mixes are prepared using the optimum dosages of glass (0.05%) and steel fibres (1%) by volume fraction. HFRSCC reinforced beams of size 1200 *200*150 mm will be casted with steel and GFRB rebars and tested to study the flexural properties such as ultimate flexural strength, load at first crack, deflection at the center, crack width and crack patterns. For the above fibred beams, load-deflection relations will be established. The HFRSCC beam made with GFRP rebars have the load carrying capacity 37.03% more than HFRSCC beam made with steel rebars. The deflection for the HFRSCC beam made with GFRP rebars is 61.52% more than beam made with steel rebar HFRSCC beam made with GFRP rebars increases the load at first crack, ultimate flexural strength, and deflection at the centre at failure and the crack width for same HFRSCC beam made with steel rebars

Support Vector Regression approach for prediction of delamination at entry and exit during drilling of GFRP Composites

The demand for Composites in the modern era have increased immensely due to its vast applications and superior properties over conventional materials. Glass Fibre Reinforced Plastic (GFRP) is one of the economic alternative to conventional engineering materials due to its high specific modulus of elasticity, high specific strength, good corrosion resistance, high fatigue strength and lightweight. Components made out from GFRP composites are usually near net shaped and require holes for assembly integration. Drilling is an important process as concentrated forces can cause major damage to the composite. Drilling of GFRP causes various damage such as thermal degradation, fibre breakage, matrix cracking and delamination. A substantial damage is caused by delamination which can occur both on the entry and exit sides of the composite, exit side delamination considered more severe. Therefore, selection of proper process parameters during drilling operation is very much essential. In the present work, a support vector regression (SVR) model is developed to predict the delamination at entry and exit during the drilling of GFRP composites. The model is developed based on the data obtained from experimentation. The model accuracy is evaluated by the three performance criteria including root mean square error (RMSE), Nash–Sutcliffe efficiency co-efficient (E) and co-efficient of determination (R2). The model provides an inexpensive and time saving alternative to study the delamination at entry and exit of the GFRP composite actual drilling operation.

Compressive and flexural behavior of glass fiber-reinforced concrete

Utilizing fibre-reinforced concrete is still a difficulty for present engineers. Generally, it is acknowledged that the mechanical, cracking and fracture qualities of fibre-reinforced concrete are much better than those of conventional concrete. The addition of fibres to the concrete matrix mitigates its fragility. Typically, short fibres are utilised in concrete to prevent cracks caused by drying and autogenous shrinkage. Currently, there is a substantial increase in the use of short alkali-resistant glass fibres. This experiment was conducted to examine the influence of glass fibre reinforcement on the compressive and flexural behaviour of concrete. This research investigates the characteristics of glass fibres reinforced concrete (GFRC) after 7 and 28 days of curing, such that GFRC may be employed in construction. Concrete containing short alkali-resistant glass fibres of 36 mm in length and 1% volume fraction (VF) was developed for this purpose. The testing findings revealed that the average compressive strength of GFRC after 28 days of curing was 72.06 MPa. The flexural properties of GFRC are determined, and the 7-day and 28-day average bending strengths of GFRC concrete samples are 6.46 MPa and 7.94 MPa, respectively, indicating that GFRC responds well under loading conditions.

Membranes for functional conditioning: Report on the design and construction of two active bending structures incorporating reused materials

This paper describes the design and assembling process of two experimental structures located in the University of Minho’s School of Architecture, Art and Design, carried out between 2020 and 2022. Both were designed using the concept of active bending, assured by poles made of Glass Fibre Reinforced Polymer (GFRP) as supporting elements to membrane mesh made in PVC coated polyester. The assembling process allowed participants to experiment all the steps related with the design and construction of membrane structures with active bending elements, considering their advantages and disadvantages. The ability of membrane structures for the functional conditioning of the built environment was explored in two different scenarios, showing that they can be adequate both in outdoor as in indoor contexts. The idea of learning by doing served as the foundation for the pedagogical practices used. Each practice was discussed and tailored to the specific situation, regarding the conditions of the site, the participants involved and the functional conditioning requirements of each space.

Studies on Self-Healing Properties of Glass Fibre Reinforced Bituminous Concrete Mixes

In the present era, numerous researchers are actively exploring diverse approaches to modify Bituminous Concrete (BC) and seeking alternative paving materials to extend the lifespan of road surfaces and to enhance the longevity and resilience of bitumen pavements, while simultaneously mitigating environmental pollution stemming from hydrocarbon materials. Among the effective materials employed for AC modification, fibers have emerged as one of the successful choice. This research focuses on investigating the inherent self-healing capabilities of bitumen when incorporating glass fibers and assess their impact on the bitumen mixture. Glass fibers are known for their elevated tensile modulus and exceptional heat resistance. The mixture containing glass fibers is evaluated for its characterisation, determining the optimal glass fiber content along with the corresponding binder content. The study encompasses an examination on optimized samples for Self-Healing by Indirect Tensile Strength, and repeated load Indirect Tensile Strength. The outcomes yielded positive results, demonstrating that the inclusion of glass fibers led to an augmentation in strength and healing, both under static and dynamic loading conditions.

Structural behavior of axially loaded high strength concrete columns reinforced longitudinally with glass fiber reinforced polymer bars

This study investigated the behaviour of axially loaded high strength concrete columns reinforced longitudinally with glass fibre reinforced polymer bars. Total six Reinforced Concrete (RC) columns and six Glass Fibre Reinforced Polymer (GFRP) reinforced concrete columns made with High Strength Concrete (HSC) with the addition of 1.20% of Alkali Resistant Glass Fibre (ARGF). The columns were cast with 1000 mm height and cross-sectional area is 150 mm x 150 mm and were tested under axial loading. The main objective of this study including to increase axial load carrying capacity and stiffness and reduce the ductility, mode of failure, and axial load-displacement response of columns. The RC columns are compared to the GFRP RC columns, and the GFRP RC columns are only carried 90% of the axial load compared to the RC columns. The Finite Element Model (FEM) was used to analyses all columns, and FEM helps predict the axial load.

Modelling and Prediction of Machining Forces During End Milling of Glass Fibre Reinforced Polymer Composites Using Regression Analysis and Artificial Neural Networks

Modelling and Prediction of Machining Forces During End Milling of Glass Fibre Reinforced Polymer Composites Using Regression Analysis and Artificial Neural Networks

Review on physical properties of glass fiber and reinforced glass fiber composite with their effect

This paper offers a literature review in the area of GF reinforced composites from the literature survey of various authors. GF reinforced with polymers and natural fibers results in lowering density, enhanced strength, and ease of manufacturing over the base-material are some of the beneficial characteristics of GF composites. Because of these advantages of GF-composites, over others it is used in many fields such as aerospace, automotive, marine, dental treatment and construction. In this paper we are going to review how the GF is use in above mention industries. We also have reviewed some hybrid reinforced composites of GF and mentioned their advantage over GF.

Method of experimental research of concrete beams with fiberglass reinforcement for bending

This article presents a methodology for experimental studies of bent concrete beams made of ordinary heavy concrete, equipped with fiberglass composite reinforcement, and data on methods for measuring the arising deformations, cracks, and deflections of prototypes of beams under the action of transverse forces.

Influence of coloring on the properties of epoxy binders and fiberglass rebar based on them

At present, polymer composite materials are widely used in the construction and automotive industries, products for which must meet not only operational, but also aesthetic requirements. Since color is one of the most important design elements, much attention is paid to the coloring of structural composites. There is a fairly wide range of different methods for coloring polymer composites, but each method has both advantages and disadvantages. This article discusses two methods for coloring a hot amine-cured epoxy composition, which is used for the manufacture of composite fiberglass reinforcement: by adding pigment and organic dyes to the epoxy composition. It has been found that organic dyes dissolve in all components of the epoxy composition, but become colorless upon heat treatment. When adding an insoluble dispersed pigment, the color remains unchanged even after the thermal curing of the epoxy matrix. The addition of up to 0.5 mass parts of iron oxide pigment (“red FEPREN TP-303”) to the epoxy binder slightly reduces the mechanical strength of the composite and significantly increases its thermal stability.