E-glass Fiber Fabrics Research Articles

Investigation behavior of gypsum soil reinforced by geosynthetics supported square footing-an experimental study

Recently, an urban expansion prompted to construction of structures on weak or unsuitable ground soils. In a sustainable view, there is a need to investigate and improve such types of soils under consideration. Gypsum soil is one of the weak soils when exposed to wetness, especially the value of bearing capacity and Collapse. The main objective of this study is to carry out several model tests for gypsum soil at a relative density of 30% for dry and wet conditions under static vertical stress. The study involved evaluating the effectiveness of soil stabilization using geosynthetics reinforced (geotextile and E-glass fiber fabric) by using single, double, and triple layers placed at different locations. Soil with a gypsum content of 47% was used. Experimental tests were carried out on soil models for the dry and saturated conditions for a relative density of 30%. The ultimate bearing capacity was calculated, as well as the ratio of improvement BCR% according to the reinforcement layers. It was found that the ultimate bearing capacity increases 100% when using E-glass fiber fabric comparing used geotextile at reinforcement triple layers (0.25B+0.5B+1B) for dry state.

Influence of stacking sequence on the mechanical properties of 3D E-glass/bamboo non-woven hybrid epoxy composites

Hybridization of composites is one of the many ways to optimize cost, manufacturing process and strength required for a particular application. This demands a need for knowledge about the best possible ways to deal with the dissimilar materials in the composite system. Very little light has been shed about the stacking sequence implemented while dealing with non-woven natural fiber mats and 3D woven glass fiber fabric as reinforcement and effects of different models on the strength of composite – which has been dealt very vividly in this research work. Two types of hybrid stacking sequence were implemented using non-woven bamboo fiber mat and 3D E-glass fiber fabric, namely H1, which has two bamboo mats at the centre with a glass fabric on either side as extreme layers, and H2, which has 3 glass fabric and 2 bamboo mat placed stacked alternatively with glass fabric being as extreme layers on either side again. For comparative purposes, 4 layers each of E-glass fabric and bamboo mat composites were also made. Tensile, flexural and ILSS tests were conducted on all four of these samples and results showed that lying between the consistent superior strength displayed by pure glass composite and inferior strength of pure bamboo composite, the H1 sample stacking sequence performed better than the H2 sample. The major reason for the failure of the hybrid composites was observed to be due to delamination at dissimilar laminae boundary which were more in H2 samples than H1 composite. Scanning Electron Microscopy was employed to understand the modes of failure.

Single and repeated low-velocity impact response of E-glass fiber-reinforced epoxy and polypropylene composites for different impactor shapes

This study focuses on the effects of low-velocity impact (LVI) response of thermoset (TS) and thermoplastic (TP) matrix-based composites. In this study, the effects of the impactor shapes on the low-velocity impact response of the composite panels that produced from different matrix was investigated. Unidirectional E-glass fiber fabrics with an areal density of 300 g/m2 as reinforcement and epoxy matrix were used to produce TS composite. The vacuum-assisted resin infusion molding (VARIM) method was used to manufacture composite panels. The thermoplastic composites were manufactured with E-glass fiber-reinforced polypropylene prepregs. The tensile strength of TS matrix-based composites is higher than TP matrix-based composites that have the same fiber volume fraction. Despite being under the same impact energy, the TP specimens possess higher perforation threshold than TS specimens. The shape of the impactor significantly affected the perforation threshold. Besides, the impact number that caused perforation reduced dramatically in conical impactor. The repeated impact number that caused perforation is 36 for hemispherical (HS) impactor, but it is only 3 for conical impactor for polypropylene matrix-based composite. Moreover, a significant effect of fiber volumetric ratio on impact resistance was observed. The perforation threshold of glass fiber-reinforced polypropylene composites for 40% and 50% fiber volume fraction are 61 and 98 J, respectively. The perforation threshold of TP and TS specimens for HS impactor that has the same stacking sequence is 61 and 55 J, respectively.

The effect of hygrothermal aging and UV radiation on the low-velocity impact behavior of the glass fiber-reinforced epoxy composites

The present work examines the effects of hygrothermal and UV radiation aging on the reinforced epoxy composites. The role of temperature in the hygrothermal aging process on tensile properties, impact behavior of composites and compression-after impact was investigated. Among four different chosen aging conditions, three of them were hygrothermal and last one was composed of both hygrothermal and UV radiation. Unidirectional e-glass fiber fabrics with an areal density 300 g/m2 as reinforcement and epoxy matrix were used. Composites were manufactured using vacuum-assisted resin infusion molding. The goal of this study was to investigate the effect of UV radiation and aging temperature with respect to the glass transition temperature. In this context, aging procedures were carried out in two different ways for 70 °C temperature with and without UV radiation. As a result of the test, the tensile strength, tensile modulus, absorbed energy, interlaminar shear strength (ILSS), and compression-after impact (CAI) strength of the glass reinforced composites decreased for all conditions. Despite being under the same ambient temperature and humidity, the samples which were exposed to UV radiation had lower mechanical properties. The reduction of tensile strength of specimens exposed to 70 °C and 70% humidity with and without UV radiation were 24% and 10%, respectively. The temperature of hygrothermal conditions significantly affected the perforation threshold. In low impact energies, delamination was the primary damage mode, while fiber breakage becomes more important in the composite at high impact energy levels.

Statistical classification for E-glass fiber fabric defects based on sparse coding

In this research, a statistical classification algorithm based on sparse coding is presented to classify the defects on E-glass fiber fabrics adaptively. First, all images are preprocessed by being convolved with the MR8 filter banks to obtain the filter responses. For the filter response space of each type of image, we will learn a Class-specific dictionary, and all the Class-specific dictionaries are concatenated to form a complete dictionary. Then, the reconstructed contribution rate of each atom of the complete dictionary to the image filter response is counted to obtain two types of histogram features of each image. Finally, the improved sparse representation classification is used to classify test defect images based on the histogram features. The proposed adaptive classification method has achieved an average classification accuracy of 96.67% on the dataset collected onsite. The results validate the superiority of the proposed method to E-glass fiber fabrics.

Experimental evaluation of temperature effect on the transverse permeability of a fibrous preform

Study of the transverse permeability of fibrous reinforcements became increasingly important when liquid molding processes started being more widely employed to obtain more complex-shaped or thicker parts. In this paper, a system specially built to measure transverse permeability of fabrics based on the correlation between pressure difference and flow rate was used to evaluate the effect of temperature on the measurements of the transverse permeability of an E-glass fiber fabric. Three fiber volume fractions (38-61%) and three temperatures were studied (20-63°C). The temperature showed no significant effect on transverse permeability of the tested fabric, even though it greatly alters the working fluid viscosity.

Experimental investigation of transverse loading on composite panels coated with different gelcoat colors subjected to UV radiation and hygrothermal aging

This study focuses on the effects of hygrothermal and UV radiation aging on the reinforced epoxy composites coated with gelcoat. The aim of this study is to investigate the influence of gelcoat colors on the tensile properties, impact behavior and thermodynamic properties of the composite panels after the aging process has been performed. Two different gelcoat colors were chosen as black and yellow. Unidirectional E-glass fiber fabrics with an areal density 300 g m−2 as reinforcement and epoxy matrix were used. Vacuum-assisted resin infusion molding (VARIM) method was used to manufacture composite panels. The tensile test specimens were prepared according to ASTM standards. Tensile strength of both fiber and transverse directions, the impact perforation threshold, and stroge modulus of the aged samples decreased compared to unaged (virgin) samples. However, the drop in mentioned properties for coated materials is less than for uncoated materials, especially in yellow coated materials. The temperature of hygrothermal conditions significantly affected the perforation threshold. Moreover, the tensile strength in transverse direction in yellow samples decreased approximately 13%, while it decreased 23% in the black coated samples. Impact perforation threshold of unaged (virgin), uncoated, coated with yellow gelcoat and coated with black gelcoat is obtained to be 75, 57, 65 and 61 J, respectively.

Effect of ultrasonic-assisted impregnation parameters on the preparation and interfacial properties of MWCNT/glass-fiber reinforced composites

AbstractIn this study, an ultrasonic-assisted impregnation method was employed to deposit carboxyl multiwalled carbon nanotubes (MWCNTs) onto the E-glass fiber fabric (GFf) for the preparation of the MWCNT-GFf reinforcer. The effects of ultrasonic power, duration and temperature on the dispersion of MWCNTs onto GFf were investigated, and the mechanical properties, interlaminar adhesion, and dynamic viscoelasticity of the resulting MWCNT-GFf-reinforced composites (MGCs) were evaluated. The results indicated that an effective dispersion of MWCNTs onto GFf without obvious breakage of the MWCNTs was achieved under an ultrasonic power of 600 W, duration of 6 min, and processing temperature of about 0°C. Compared with the GFf-reinforced composite, the tensile strength, flexural strength and interlaminar shear strength of the MGCs exhibited maximum increments of 38.4%, 34.6% and 47.1%, respectively. Moreover, the storage moduli and glass-transition temperatures of the MGCs were significantly enhanced. The ultrasonic parameters were of key importance for dispersing MWCNTs onto GFf and improving the interfacial properties of the composites.

Effect of ply lay-up and curing pressure on void content in GFRP laminates of unsaturated polyester resin-reinforced woven E-glass fibers

This paper describes a laminate curing process by hand lay-up of plain-weave woven Glass fiber-reinforced polymer (GFRP) composite composed of unsaturated polyester resin reinforced with E-glass fiber fabric, EWR-600B. Symmetrical and non-symmetrical ply orientation arrangements were introduced with respect to different curing pressures to produce consistent composite panels according to the British standard code: BS 1268 (2001) for evaluations of void content and physical properties. Quantitative analysis of volume and weight fractions and void volume content were investigated according to the ASTM code: D 2734. Woven GFRP composites fabricated under different curing pressures of 351.2 (35.8 kg/m2), 687.7 (70.1 kg/m2), 1020.2 (104 kg/m2) and 1355.7 Pa (138.2 kg/m2) showed minimal significant effect on volume and weight fractions of symmetrical and non-symmetrical ply lay-up arrangement, whereas 4 % void content still fulfilled the limit of medium quality composite.

Properties of MWCNT–glass fiber fabric multiscale composites: mechanical properties, interlaminar adhesion, and thermal conductivity

In this study, multiscale MWCNT–glass fiber fabric (MGFf) preforms with multiwalled carbon nanotubes (MWCNTs) dispersed onto commercial E-glass fiber fabric (GFf) was used to fabricate the MGFf multiscale composites. The mechanical properties, interlaminar shear strength (ILSS), dynamic viscoelasticity and thermal conductivity of MGFf multiscale composites were investigated using a universal material testing machine, dynamic mechanical thermal analyzer and transient plane source method. Furthermore, the reinforcing mechanisms of MWCNTs on interlaminar adhesion of MGFf multiscale composites were explored using scanning electron and transmission electron microscopy and energy dispersive X-ray spectrometry. Compared with the GFf composite, the ILSS and thermal conductivity of MGFf multiscale composites were increased by 40.5% and 55.3%, respectively; both of the tensile and flexural properties of MGFf multiscale composites were significantly enhanced; the glass transition temperature of MGFf multiscale composites was also raised. In addition, the interface thickness was increased with the addition of MWCNTs, and MWCNTs in MGFf multiscale composites behaved as hooked fibers to improve the interlaminar adhesion. The work demonstrates the great promise of MGFf preforms toward practical industrial application in manufacturing multifunctional fiber composites with high strength and modulus, high shear resistance and good thermal conductivity.

Load-bearing capacity and fracture behavior of glass fiber-reinforced composite cranioplasty implants.

Glass fiber-reinforced composites (FRCs) have been adapted for routine clinical use in various dental restorations and are presently also used in cranial implants. The aim of this study was to measure the load-bearing capacity and failure type of glass FRC implants during static loading with and without interconnective bars and with different fixation modes. Load-bearing capacities of 2 types of FRC implants with 4 different fixation modes were experimentally tested. The sandwich-like FRC implants were made of 2 sheets of woven FRC fabric, which consisted of silanized, woven E-glass fiber fabrics impregnated in BisGMA-TEGDMA monomer resin matrix. The space between the outer and inner surfaces was filled with glass particles. All FRC implants were tested up to a 10-mm deflection with load-bearing capacity determined at 6-mm deflection. The experimental groups were compared using nonparametric Kruskal-Wallis analysis with Steel-Dwass post hoc test. FRC implants underwent elastic and plastic deformation until 6-mm deflection. The loading test did not demonstrate any protrusions of glass fibers or cut fiber even at 10-mm deflection. An elastic and plastic deformation of the implant occurred until the FRC sheets were separated from each other. In the cases of the free-standing setup (no fixation) and the fixation with 6 screws, the FRC implants with 2 interconnective bars showed a significantly higher load-bearing capacity compared with the implant without interconnective bars. FRC implants used in this study showed a load-bearing capacity which may provide protection for the brain after cranial bone defect reconstruction.

Effect of silane hydrolysis on the interfacial adhesion of carbon nanotubes/glass fiber fabric-reinforced multiscale composites

Three types of multiwall carbon nanotubes (MCNTs)/glass fiber fabrics (MGf) were prepared by dispersing industrial-grade MCNTs onto commercial E-glass fiber fabrics (GFfs) through an ultrasonic-assisted impregnation deposition method. The multiscale MGf-reinforced composites were fabricated by the vacuum infusion process. The effect of γ-aminopropyltrimethoxysilane (APS) or APS hydrolysis on the MCNT dispersion and the interfacial bonding between MCNTs and glass fiber were investigated by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy and their flexural stiffness, respectively. The interfacial adhesion of MGf composites was evaluated by interlaminar shear strength (ILSS) and dynamic mechanical thermal analysis. The results indicated that MCNTs on the MGf surface could form an interpenetrating network and act as anchors to interlock glass fiber with epoxy. The initial storage modulus and glass transition temperature of the MGf composites clearly increased, while the first loss factor of the MGf composites decreased by 30.0–45.0% compared with that of the GFf composite. Whether or not APS was hydrolyzed, it helped the MCNTs disperse on the GFf surface by chemical bonds. The ILSS of the multiscale composite with APS-treated MCNTs was enhanced significantly, while that with hydrolyzed APS-treated MCNTs (MGf-h) had a slight increase. APS hydrolysis increased the flexural rigidity of the MGf-h.

P241 Évaluation in vitro d’une nouvelle gamme de pompes pour nutrition entérale

The low velocity impact behavior of E-glass/basalt reinforced hybrid laminates, manufactured by resin transfer moulding technique, was investigated. Specimens prepared with different stacking sequences were tested at three different impact energies, namely 5 J, 12.5 J and 25 J. Residual post-impact mechanical properties of the different configurations were characterized by quasi static four point bending tests. Post-impact flexural tests have been also monitored using acoustic emission in order to get further information on failure mechanisms. Results showed that basalt and hybrid laminates with an intercalated configuration exhibited higher impact energy absorption capacity than glass laminates, and enhanced damage tolerance capability. Conversely, the most favorable flexural behavior was shown by laminates with symmetrical sandwich-like configuration (E-glass fiber fabrics as core and basalt fiber fabrics as skins).

Effect of basalt fiber hybridization on the impact behavior under low impact velocity of glass/basalt woven fabric/epoxy resin composites

The low velocity impact behavior of E-glass/basalt reinforced hybrid laminates, manufactured by resin transfer moulding technique, was investigated. Specimens prepared with different stacking sequences were tested at three different impact energies, namely 5J, 12.5J and 25J. Residual post-impact mechanical properties of the different configurations were characterized by quasi static four point bending tests. Post-impact flexural tests have been also monitored using acoustic emission in order to get further information on failure mechanisms. Results showed that basalt and hybrid laminates with an intercalated configuration exhibited higher impact energy absorption capacity than glass laminates, and enhanced damage tolerance capability. Conversely, the most favorable flexural behavior was shown by laminates with symmetrical sandwich-like configuration (E-glass fiber fabrics as core and basalt fiber fabrics as skins).

Experimental study of joining thick composites reinforced with non-crimp 3D orthogonal woven E-glass fabrics

A comprehensive experimental study was performed to determine the strength of several co-cured and adhesively bonded joints of composite panels reinforced with non-crimp 3D orthogonal woven E-glass fiber fabrics. Various single-lap and double butt-strap joints were fabricated using co-curing and adhesive bonding and tested in uniaxial in-plane tension. The co-cured joints included special stepped 3D woven preforms, stitched and stapled joints. The joint strength appears to have the lowest values for the co-cured single-lap joints, intermediate values for the co-cured double butt-strap joints and the highest values for the adhesively bonded double butt-strap joints. Stitching and stapling dry preforms resulted in significant increase of the co-cured single-lap joint strength. In the range of strap thicknesses studied for the bonded joints, thinner straps provide a higher joint break force than thicker ones. Tapering strap ends to as small angle as possible was found to be the most effective method of increasing break force of double butt-strap bonded joints.

The Tensile Fatigue Behavior of a Glass-fiber Reinforced Plastic Composite Using a Hybrid-toughened Epoxy Matrix

A thermosetting epoxy-polymer was modified by incorporating 9 wt% of carboxyl-terminated butadiene-acrylonitrile rubber microparticles and 10 wt% of silica nanoparticles. The tensile fatigue behavior at a stress ratio, R = 0.1 for both the neat-epoxy polymer (i.e., unmodified) and the hybrid-epoxy polymer was first investigated. The fatigue life of the hybrid-epoxy polymer was about six to ten times higher than that of the neat-epoxy polymer. Secondly, the neat- and the hybrid-epoxy resins were infused into a quasi-isotropic lay-up, E-glass fiber fabric via a ‘Resin Infusion under Flexible Tooling’ set-up to fabricate glass-fiber reinforced plastic (GFRP) composite panels. The tensile fatigue tests at a stress ratio, R = 0.1 were performed on both of these GFRP composites during which the matrix cracking and stiffness degradation were routinely monitored. The fatigue life of the GFRP composite increased by about six to ten times due to employing the hybrid-epoxy matrix, compared to employing the neat-epoxy matrix. Suppressed matrix cracking and a reduced crack propagation rate were observed in the hybrid-epoxy matrix, which resulted from the various toughening micromechanisms induced by the presence of both the rubber microparticles and silica nanoparticles. These factors were considered to contribute towards the enhanced fatigue life which was observed for the GFRP composite employing the hybrid-epoxy matrix.