E-glass Epoxy Composites Research Articles

Effects of Low Temperature and Water Saturation on the Blast Response of Carbon and E-Glass Epoxy Composites

Effects of Low Temperature and Water Saturation on the Blast Response of Carbon and E-Glass Epoxy Composites

Investigation on the Durability of E-Glass/Epoxy Composite Exposed to Seawater at Elevated Temperature.

In this manuscript, the durability of the E-glass/epoxy composite was determined under a seawater environment. The effect of harsh environment was investigated in terms of seawater absorption, microstructure and degradation in mechanical properties. E-glass epoxy composite specimens were conditioned in gulf seawater at 23 °C, 65 °C and 90 °C for the period of 12 months. It was observed that the mass of the samples increased after the immersion of 12 months at 23 °C and 65 °C whereas it reduced at 90 °C. The salt deposition was observed at the surface of specimens without any crack for the seawater conditioning at 23 °C and 65 °C. The swelling and crack formation were significantly visible on the surface of the specimen immersed for 12 months at 90 °C. It indicates that the degradation mechanism accelerated at elevated temperature results fiber/matrix debonding. The tensile test indicates slight variation in the elastic modulus and reduction in strength of E-glass epoxy composite by 1% and 9% for specimens immersed at 23 °C and 65 °C respectively. However, at 90 °C, the tensile strength sharply decreased to 7% and elastic modulus significantly increased in the exposure of 12 months. A prediction approach based on a time-shift factor (TSF) was used. This model predicted that the strength retention of E-glass/Epoxy composite will be reduced to 7% in 450 years after immersion in seawater at 23 °C. Lastly, the activation energy for the degradation of the composite was calculated.

Effect of Delamination on Natural Frequencies of E-glass and S-glass Epoxy Composite Plates

The delamination is one of the major modes of failure occurring in the laminated composite due to insufficient bonding between the layers. In this paper, the natural frequencies of delaminated S-glass and E-glass epoxy cantilever composite plates are presented by employing the finite element method (FEM) approach. The rotary inertia and transverse shear deformation are considered in the present study. The effect of parameters such as the location of delamination along the length, across the thickness, the percentage of delamination, and ply-orientation angle on first three natural frequencies of the cantilever plates are presented for S-glass and E-glass epoxy composites. The standard eigenvalue problem is solved to obtain the natural frequencies and corresponding mode shapes. First three mode shape of S-Glass and E-Glass epoxy laminated composites are portrayed corresponding to different ply angle of lamina.

Kerf analysis and delamination studies on glass-epoxy composites cut by abrasive water jet

Abrasive water jet machining is suitable for machining both conductive and non-conductive materials. As the demand is increasing for the polymer composites in the industries, researches are concentrating on machining of the polymer composites as the delamination is the major problem in the machining. In this work the polymer composite used is E-glass epoxy composites prepared by hand-layup and compression molding. Kerf analysis is carried out to judge the optimum values of parameters. The five factors traverse speed, pressure, abrasive mass flow rate, stand-off distance and garnet size is taken into consideration. According to this study, garnet size, pressure and SOD are the significant factors for kerf and SEM analysis is carried out for selected samples. No delamination and no abrasive embedment is observed. Fiber pull in the laminate observed at the higher pressure condition.

PENGARUH ORIENTASI SERAT KOMPOSIT E-GLASS EPOXY TERHADAP SIFAT MEKANIK PEGAS DAUN TUNGGAL DENGAN METODE ELEMEN HINGGA

Single leaf spring is one of the suspension systems on vehicles that function as vibration dampers which usually use steel. One type of steel that is often used in making single leaf springs is 55Si7 steel. However, at this time composite materials began to be used as an alternative material to replace steel. One of the composite materials used as a substitute for steel is E-glass epoxy. This study aims to determine differences in the characteristics of steel leaf springs and e-glass epoxy composites. In addition, the effect of orientation of the fiber direction to deformation, stress, and safety factors on leaf springs was also carried out in this study. The analytical method used is finite element. The results showed that the composite leaf springs had lower stress than steel leaf springs. E-glass epoxy composite leaf springs variation D (fiber orientation 45º / -45º) showed the lowest stress and highest safety factor with values ​​of 596 MPa and 1.4 respectively.

Low-velocity impact behavior of glass fiber epoxy composites modified with nanoceramic particles

The introduction of new type of nanomaterials has provided challenges in a deeper level understanding of mechanical behavior and failure mechanisms of fiber-reinforced composites. In this study, a comparison of low-velocity impact behavior of E-Glass epoxy composites modified with 10 wt% nanosilica and 2.5 wt% Nafen™ alumina nanofibers manufactured using vacuum-assisted resin transfer molding is reported. Low-velocity impact tests at three impact energies of 29 J, 39 J, and 50 J are conducted and impact responses, such as impact strength, absorbed energy, and damage area are determined and compared for the two nanoparticles. The damage sustained by composite samples is evaluated by optical microscopy and infrared thermography. Nanosilica-incorporated composites showed rigid behavior, whereas alumina nanofiber-modified composites showed increased stiffness at increased energy of impact as observed from the initial stiffness and deflection of samples. The degree of damage in case of 10 wt% nanosilica-modified composites is reduced by 7.04%, 3.96%, and 7.92% for energy levels of 29 J, 39 J, and 50 J respectively when compared to nonmodified composites, whereas 2.5 wt% alumina nanofiber-modified composites showed 1.66%, −7.35%, and 26.39% for energy levels of 29 J, 39 J, and 50 J, respectively.

Moisture absorption behavior of stressed and unstressed E-Glass epoxy composites under varying conditions of temperature

In order to meet the market demands the practitioners are searching for light weight and higher strength materials at lower cost In this context the mechanical and structural properties of fibre reinforced plastic FRP satisfy the market demands and has been used worldwide for many industrial applications But in the due course of time a composite part behaves like a sponge and absorbs moisture which leads to increase in weight and degradation of mechanical properties This loss in mechanical properties may be due to plasticization of matrix by water and degradation of fiber matrix interfacial bond Hence the present study analyses the moisture absorption behavior of E Glass epoxy Inter Laminar Shear Strength ILSS stressed and unstressed specimens of fiber weight fraction

Aluminum and E-glass epoxy plates behavior subjected to shock loading

The terrorist attacks and dangers by bomb blast have turned into an emerging issue throughout the world and the protection of the people and structures against terrorist acts depends on the prediction of the response of structures under blast and shock load. In this paper, behavior of aluminum and unidirectionally reinforced E-Glass Epoxy composite plates with and without focal circular holes subjected to shock loading has been identified. For isotropic and orthotropic plates (with and without holes) the classical normal mode approach has been utilized as a part of the processing of theoretical results. To obtain the accurate results, convergence of the results was considered and a number of modes were selected for plate with and without hole individually. Using a shock tube as a loading device, tests have been conducted to composite plates to verify the theoretical results. Moreover, peak dynamic strains, investigated by experiments are also compared with the theoretical values and deviation of the results are discussed accordingly. The strain-time histories are likewise indicated for a specific gauge area for aluminum and composite plates. Comparison of dynamic-amplification factors between the isotropic and the orthotropic plates with and without hole has been discussed.

Buckling analysis of a ring stiffened hybrid composite cylinder

This study aims to understand the response of the ring stiffened cylinders made up of hybrid composites subjected to buckling loads by using the concepts of Design of Experiments (DOE) and optimization by using Finite Element Method (FEM) simulation software Ansys workbench V15. Carbon epoxy and E-glass epoxy composites were used in the hybrid composite. This hybrid composite was analyzed by using different layup angles. Central composite design (CCD) was used to perform design of experiments (D.O.E) and kriging method was used to generate a response surface. The response surface optimization (RSO) was performed by using the method of the multi-objective genetic algorithm (MOGA). After optimization, the best candidate was chosen and applied to the ring stiffened cylinder and eigenvalue buckling analysis was performed to understand the buckling behavior. Best laminate candidates with high buckling strength have been identified. A generalized procedure of the laminate optimization and analysis have been shown.

Stress-Controlled Fatigue Testing of E-Glass Epoxy Composite: Monitoring of Micro-Damage

The paper deals with progressive and fatigue damage of long fiber E-glass epoxy composite, its residual stiffness degradation and corresponding transverse matrix crack density induced by load-controlled tension. Constant-amplitude fatigue tests in repeated tension of plain [±60]S; [±30]S; [0]8 and [0/902/±45/90]S samples were performed. Sudden onset of transverse matrix cracking and consequent gradual increase of its density has been observed in off-axis plies. The crack density increases with increasing number of cycles or load. Consequently, residual stiffness of the laminate decreases. It has been concluded that progressive/fatigue damage of the laminate is not a continuous homogenous process but the series of discrete sudden events emerging at ply level.

A Self-sealing Fiber-reinforced Composite

We describe a self-sealing plain weave E-glass epoxy composite with the healing components, microencapsulated dicyclopentadiene (DCPD), and paraffin wax coated Grubbs’ catalyst dispersed throughout the matrix. In this work, sealing is assessed through use of a pressure cell apparatus to detect nitrogen flow through the thickness direction of a damaged composite. A controlled amount of microcracking is introduced through cyclic indentation of opposing surfaces of the sample. The resulting damage zone is proportional to the indentation load. We investigate the effect of DCPD microcapsule size and concentration on the self-sealing ability of plain weave E-glass epoxy composites. For 51 µm diameter capsules (6.5 wt%), 67% of the self-sealing composite panels fully seal with no leaking, compared to 0% of the control panels with no sealing ability. When the amount of damage is reduced, 100% of the self-sealing samples resealed. Sealing performance decreases with smaller diameter capsules (18 µm diameter) and lower capsule concentrations (2.7 wt%), indicating that there is a minimum capsule size and concentration to deliver enough healing agent to seal a given damage volume.

Assessment of Dielectrometry for Characterization of Processing and Moisture Absorption in FRP Composites

The increasing use of ambient cured resin systems for the fabrication of composites used in structural components such as in civil infrastructure creates a need for monitoring cure progression over time as well as for tracking changes due to environmental exposure during the extended period of time needed to attain full cure. Further, there is a need for the development of methods to monitor the health of structures in the field for applications such as column retrofit, external strengthening of girders and slabs, and even bridge decks. This paper investigates the application of dielectrometry to the characterization of E-glass epoxy composites exposed to deionized water. Results are correlated with DSC and moisture absorption. It is shown that a direct correlation between moisture absorption and permittivity can be obtained.

Stress analysis of laminated E-glass epoxy composite plates subject to impact dynamic loading

The transient response of an E-glass epoxy laminated composite plate impacted by a steel circular cylinder is analyzed. The analysis is performed by using a three-dimensional hybrid stress finite element program. The contact force between the projectile and the laminated plate is modeled by the Hertzian impact law. The predicted transverse deflection at the center of the laminated plate agrees with the deflection determined experimentally. The effects of projectile velocity and thickness of the laminated plate on the impacted stress distributions and the central transverse deflection are also investigated.