Hybrid Nanocomposite Laminates Research Articles

The Reinforcement Effect of Nanoclay on the Damping Characteristics of Hybrid Laminated Composites

The Hybrid Nanocomposite (HNC) laminates are processed by reinforcing the chopped strand mat glass fiber and organically modified montmorillonite clay (OMT) in the polyester matrix. The different percentage by weight (1, 2, 3, and 5% ) of OMT are mixed by high speed shear mixer into the polyester matrix and then the HNC laminates are fabricated by introducing pre-mixed polyester-clay into the CSM by hand lay-up technique. A tensile test result reveals that nanoclay in polyester matrix significantly improves the tensile modulus and strength of HNC. The results also indicate that increasing the amount of nanoclay beyond 2% by weight reduces the mechanical properties but surpassing the basic glass fiber filled system. The reinforcing effect of clay enhances the flexural modulus and strength. Considerable improvement in impact energy absorption is seen from the impact test. Dynamic mechanical analysis shows that incorporation of nanoclay improves the storage modulus and Loss tangent of HNC. Free vibration tests and logarithmic decrement methods are used to predict the dynamic characteristics such as natural frequency, and damping factor for the first four modes of different clay concentrations. Dynamic results show that second phase nanoscale dispersion between the matrix and E-glass fiber significantly enhances the internal damping of hybrid composites.

Fatigue failure of hybrid nanocomposite laminates with kinked single- and double-edged cracks

Mechanical properties and fatigue responses of hybrid Ti/APC-2 neat and nanocomposite laminates with kinked single- and double-edged cracks were investigated. Through the tensile tests the load vs. displacement diagrams, the mechanical properties and the failure mechanisms were received. Also, for cyclic tests the fatigue responses of load vs. cycles curves, fatigue life and the process of failure mechanisms were obtained. The length of cracks increasing and kink angles decreasing, their mechanical properties were decreased. The mechanical properties and fatigue life of nanocomposite laminates were improved slightly over those of neat laminates. It was attributed to uniformly spreading the nanoparticles, not concentrated at the tips of cracks and along the path of crack growth. The stress intensity factors (SIFs) at the tips of kinks were obtained for applications. The two crack tips run around until they merge together with a small broken ellipse.

Study on mechanical properties of epoxy based Kenaf/Banana/Glass fiber hybrid nano composites

The composite materials usually contribute excellent, typical mechanical and physical properties as it combines the reinforcements to obtain the desirable properties while restraining their minimum desirable properties. At present the composite materials assume a huge part in the aviation division, vehicle segment and other connected science applications as they uncover the power level to weight proportion and modulus to weight extent. Elite composites created from glass, kenaf, banana and graphene filaments are utilized in polymeric networks broadly as application in aviation and space vehicle innovation. In the present study, the hybrid nano composite laminates were prepared with different weight percentage of graphene as nano filler and reinforcing material as kenaf, banana and glass fiber with epoxy resin. The results shows that by adding the graphene in epoxy resin improves the mechanical properties of hybrid nano composites and also found that the performance of kenaf/glass fiber hybrid nano composites is better than the banana/glass fiber hybrid nano composites.

WITHDRAWN: Wear analysis of woven glass / nanofiller fiber reinforced hybrid composites

This article primarily investigates the tribological behavior of the hybrid nanocomposite subjected to wear analysis. The hybrid nanocomposite laminates were prepared using woven roven glass reinforced in epoxy resin matrix, in which the nano Cerium(IV)-Zirconium(IV)Oxide was used as filling material. The influence of the nano particle content was studied by varying the weight percentage of nanoparticle (0.5, 1, and 1.5 wt%). The mechanical stirring was employed for better dispersion of nanoparticle in the matrix. These laminate was performed with wear analysis by using pin-on-disc arrangement, with specific load, velocity and sliding distance value. It is visible that the wear was minimized on the addition of the nanoparticle. When fibious quantity of nano particle (1 wt%) included, the specific wear rate was minimized upto 65%. The homogenously dispersed nano Cerium(IV)-Zirconium(IV)Oxide reduced the wear abrasives. The high resolution HRSEM and microscopic images were used to examine the morphology of the hybrid nanocomposite.

Fabrication and characterization of functionally graded nanoclay/glass fiber/epoxy hybrid nanocomposite laminates

In this work, hardness, tensile, impact, bearing strength and water absorption tests were performed to study the mechanical properties of stepwise graded and non-graded hybrid nanocomposites. Three different stepwise graded nanocomposites and one non-graded (homogeneous) nanocomposite with the same geometry and total nanoclay content of 10 wt% were designed and prepared. Moreover, one neat glass fiber laminate was manufactured. The results of the tests indicated that addition of the graded and non-graded nanoclay improves hardness over neat glass fiber reinforcement. The maximum increase in hardness of about 53% over neat specimen is obtained for specimens that have the highest weight percentage (2 wt%) of the clay nanoparticles on its surface (S-specimen and the side of F-specimen that reinforced with 2 wt% nanoclay). The gradation process results in an increase in hardness of about 11% compared with non-graded (homogeneous) specimen. In addition, an improvement of 11.9% in strain-to-failure is achieved with specimen having greatest amount of nanoclay in the middle over neat glass fiber/epoxy composite. The other nanoclay-filled glass fiber composites have strain-to-failure close to neat glass fiber/epoxy. The addition of nanoclay reinforcement has insignificant effect on ultimate tensile strength, tensile modulus, water absorption, bearing strength and impact strength compared with neat glass fiber/epoxy.

Improvement of Hardness and Wear Resistance of Glass Fiber-Reinforced Epoxy Composites by the Incorporation of Silica/Carbon Hybrid Nanofillers

ABSTRACTThe tribological performance of hybrid composite (epoxy reinforced with woven, nonwoven tissue glass fibers, silica and carbon black nanoparticles) was investigated. Two methods were used to ensure good dispersion of nanoparticles in epoxy resin which were ultrasonic processor and magnetic stirrer. The effect of silica and/or carbon black nanoparticle content on microindentation hardness and wear properties of the neat glass fiber-reinforced epoxy composites was investigated. The results from the wear test indicated that, under all applied loads, incorporation of silica and carbon black nanoparticles either single or combined significantly improved the wear resistance of neat glass fiber reinforced epoxy. A significant increase in hardness of the hybrid nanocomposite laminates was achieved. Analysis of variance was developed to study the optimal wear testing parameters on composite samples. The most significant parameter is the time, followed by nanoparticle (silica and carbon black) content.

Fatigue response of hybrid magnesium/APC-2 nanocomposite laminates at elevated temperature

AS-4/PEEK APC-2 nanocomposite laminates and Mg/APC-2 hybrid nanocomposite laminates were fabricated. The mechanical properties and fatigue response of laminates were obtained due to tensile and cyclic tests at room and elevated temperatures. The surface treatment of chemical etching on Mg sheets resulted in strong bonding with APC-2 laminates. The nanoparticles SiO2 of optimal weight were uniformly spread on the faces of APC-2. From the tensile test the mechanical properties, such as ultimate strength and stiffness, of cross-ply APC-2 nanocomposite laminates were found higher than those of quasi-isotropic nanocomposite laminates. The ultimate strength of hybrid nanocomposite laminates was predicted satisfactorily well with experimental data by using the rule of mixtures.As for cyclic tests we received the data of applied stress vs. cycles and plotted the S-N curves. Also, the failure mechanisms were observed. It was found APC-2 quasi-isotropic nanocomposite laminates possessed better fatigue resistance than that of the cross-ply nanocomposite laminates. Through the regression of fatigue data we proposed the semi-empirical model for APC-2 nanocomposite laminates and the theoretical model for hybrid nanocomposite laminates. Both models predicted the results of durability/life in good agreement with experimental data. The theoretical model for hybrid nanocomposite laminates was simple, conservative and precise.

Enhancement of water barrier properties and tribological performance of hybrid glass fiber/epoxy composites with inclusions of carbon and silica nanoparticles

Water barrier properties and tribological performance (hardness and wear behavior) of new hybrid nanocomposites under dry and wet conditions were investigated. The new fabricated hybrid nanocomposite laminates consist of epoxy reinforced with woven and nonwoven tissue glass fibers and two different types of nanoparticles, silica (SiO2) and carbon black nanoparticles (C). These nanoparticles were incorporated into epoxy resin as a single nanoparticle (either SiO2 or C) or combining SiO2 and C nanoparticles simultaneously with different weight fractions. The results showed that addition of carbon nanoparticles with 0.5 and 1 wt% resulted in maximum reduction in water uptake by 28.55% and 21.66%, respectively, as compared with neat glass fiber reinforced epoxy composites. Addition of all studied types and contents of nanoparticles improves hardness in dry and wet conditions over unfilled fiber composites. Under dry conditions, maximum reduction of 47.26% in weight loss was obtained with specimens containing 1 wt% carbon nanoparticles; however, in wet conditions, weight loss was reduced by 17.525% for specimens containing 0.5 wt% carbon nanoparticles as compared with unfilled fiber composites. Diffusion coefficients for different types of the hybrid nanocomposites were computed using Fickian and Langmuir models of diffusion. Copyright © 2017 John Wiley & Sons, Ltd.

The buckling strength of the new hybrid nanocomposite laminates using combination of layered and particulate nano fillers

This article experimentally investigates the buckling strength of carbon fiber–reinforced polymer laminates. Samples were made with 16 layers of carbon fibers in four orientations of 0°, 30°, 60°, and 90°. Nano silica (SiO2) and nano clay were used as fillers for enhancement of the buckling strength of carbon fiber–reinforced polymer laminates. The Taguchi method was used for design of experiments and optimizing the three input factors: nano silica, nano organoclay, and carbon fiber orientation. From the results, first, it was found that the most buckling strength belonged to the samples with the fiber orientation of 0° and the minimum strength belonged to the composite laminates with the 90° orientation of carbon fiber. Second, the use of two nano fillers in quaternary laminates (epoxy/carbon fiber/silica/clay) has increased the buckling strength of laminates about 45.5% and 22.5% in comparison with binary and ternary laminates, respectively. The binary laminates were made from carbon fiber/epoxy resin and the ternary laminates included carbon fiber/clay/epoxy. Third, the elastic modulus of laminates increased with an increase in the nano SiO2 content. The most effective parameters according to the analysis of variance results were as follows: carbon fiber orientation, nano silica, and nano organoclay, with a probability value of 99%, 95%, and 90%, respectively. Finally, the analytical analysis was done according to the classical laminated plate theory for obtaining the buckling force and verifying and comparing the results with experimental buckling tests. The results obtained from classical laminated plate theory for two certain laminates were in excellent agreement with those obtained from experimental results.

Fabrication and mechanical properties of Ti/APC-2 hybrid nanocomposite laminates at elevated temperatures

The Ti/APC-2 hybrid cross-ply nanocomposite laminates were successfully fabricated by the modified diaphragm curing process. The titanium thin sheets were surface treated by chromic acid anodizing to achieve superior bonding with APC-2 laminates. The nanoparticles SiO2 were uniformly spread on the interfaces of APC-2. The tensile tests at room and elevated temperatures were conducted to obtain the mechanical properties. It is interesting to find a knee point in each stress–strain curve. To predict and verify the feature of knee point the residual stresses and strains were calculated by simple methods. Adopting the residual stress effect and rule of mixtures, the analytical stress–strain curves at elevated temperatures were obtained. The data and mechanisms of the knee point in hybrid laminates were verified and highlighted. The predicted results of ultimate strength, longitudinal stiffness and the knee point are all in very good agreement with the experimental data.

Fatigue Residual Properties of Ti/APC-2 Nanocomposite Laminates after Low-Velocity Impact

The post mechanical behavior of Ti/APC-2 hybrid nanocomposite laminates after low velocity impact was investigated. The three layered Ti/APC-2/Ti cross-ply nanocomposite laminates were fabricated according to the modified the diaphragm curing process. Each sample, L×W×t=240mm×25mm×1.55mm, was first subjected to free drop of a rigid steel sphere (diameter=12.7mm) of 1m and 2m high. Then, the samples were due to static tensile tests at room temperature to measure their residual ultimate strength and longitudinal stiffness as the base-line data for constant stress amplitude tension-tension cyclic tests. The corresponding S-N curve, fatigue strength and life were obtained. Also, the failuremechanisms were observed.The mechanical properties do not reduce significantly due to low-velocity impact. Similarly, the fatigue resistance of impacted samples does not lose much. The enhancement by nanoparticles and superior bonding capability of matrix PEEK with Ti sheets take the responsibility of improvement of mechanical responses.

铝合金/碳纤维/聚醚醚酮混和十字迭奈米复材积层板之研制与高温下机械行为

创新的超性能Al/APC-2混和十字迭奈米复材积层板已成功研制。众所皆知的脱层问题已由铝板的电镀表面处取代传统的铬酸化学蚀刻法大致排除。添加最佳化的二氧化硅奈米颗粒在APC-2十字迭迭层中甚至在高温下都可增强其机械性能。由所得的混和奈米复材积层板之数据，如拉伸强度与纵向劲度等机械性能可以看出其机械性能较化学蚀刻法强6%至10%。至于高温下拉伸-拉伸固定应力振幅疲劳试验，其应力-振次(S-N)曲线会随着温度上升而下降。然而由相对应温度之极限强度所无因次化的应力-振次曲线混在一起，而它们在高于105振次后会分开。这充分证明了拥有超强性能的混合奈米复材积层板已完成。并且高温下之拉伸与疲劳试验下皆无脱层，明显的展现了优良的混和积层板已制作完成。 The innovatively high performance AL/APC-2 hybrid cross-ply nanocomposite laminates were successfully fabricated. The well-known problem of delamination was mostly eliminated by the surface treatment of electroplating of Al 2024 sheets, instead of conventionally chemical etching by CrO3 etchants. Additions of optimal nanoparticles of SiO2 into APC-2 cross-ply laminates were used to improve the mechanical properties of hybrid laminates even at elevated temperature. From the received data, the mechanical proper ties, such as ultimate tensile strength and longitudinal stiffness, of hybrid nanocomposite laminates by electroplating are better than those by chemical etching about 6% to 10%. As for the tension-tension (T-T) constant stress amplitude cyclic tests at elevated temperature, the applies stress vs. cycles (S-N) curves go downwards as the temperature rising. However, the normalized S-N curves, by the corresponding ultimate strength at specific temperature, become mixed together. They are separate at least over 105 cycles. That evidently demonstrate the superior properties of the hybrid nanocomposite laminates have been achieved. Also, no delaminations were found in tensile and cyclic tests at elevated temperature. That significantly shows a nearly perfect bonding in hybrid laminates is made.

铝合金/碳纤维/聚醚醚酮混和十字迭奈米复材积层板之研制与高温下机械行为<br>Fabrication and Mechanical Behavior of Al/APC-2 Hybrid Cross-Ply Nanocomposite Laminates at Elevated Temperature

创新的超性能Al/APC-2混和十字迭奈米复材积层板已成功研制。众所皆知的脱层问题已由铝板的电镀表面处取代传统的铬酸化学蚀刻法大致排除。添加最佳化的二氧化硅奈米颗粒在APC-2十字迭迭层中甚至在高温下都可增强其机械性能。由所得的混和奈米复材积层板之数据，如拉伸强度与纵向劲度等机械性能可以看出其机械性能较化学蚀刻法强6%至10%。至于高温下拉伸-拉伸固定应力振幅疲劳试验，其应力-振次(S-N)曲线会随着温度上升而下降。然而由相对应温度之极限强度所无因次化的应力-振次曲线混在一起，而它们在高于105振次后会分开。这充分证明了拥有超强性能的混合奈米复材积层板已完成。并且高温下之拉伸与疲劳试验下皆无脱层，明显的展现了优良的混和积层板已制作完成。 The innovatively high performance AL/APC-2 hybrid cross-ply nanocomposite laminates were successfully fabricated. The well-known problem of delamination was mostly eliminated by the surface treatment of electroplating of Al 2024 sheets, instead of conventionally chemical etching by CrO3 etchants. Additions of optimal nanoparticles of SiO2 into APC-2 cross-ply laminates were used to improve the mechanical properties of hybrid laminates even at elevated temperature. From the received data, the mechanical proper ties, such as ultimate tensile strength and longitudinal stiffness, of hybrid nanocomposite laminates by electroplating are better than those by chemical etching about 6% to 10%. As for the tension-tension (T-T) constant stress amplitude cyclic tests at elevated temperature, the applies stress vs. cycles (S-N) curves go downwards as the temperature rising. However, the normalized S-N curves, by the corresponding ultimate strength at specific temperature, become mixed together. They are separate at least over 105 cycles. That evidently demonstrate the superior properties of the hybrid nanocomposite laminates have been achieved. Also, no delaminations were found in tensile and cyclic tests at elevated temperature. That significantly shows a nearly perfect bonding in hybrid laminates is made.

The Effect of Electron Irradiation on the Mechanical Properties of MWCNT/Carbon Fiber Reinforced Hybrid Nanocomposites

In our work carbon fiber/epoxy composite and multiwalled carbon nanotube/carbon fiber/epoxy hybrid nanocomposite laminates have been prepared by resin transfer moulding (RTM) technology. The specimens have been irradiated using a high energy electron gun with multiple doses. The effect of the electron irradiation has been characterized using three point bending, interlaminar shear and instrumented falling weight impact tests.

Tensile and Fatigue Testings of Hybrid Al/APC-2 Nanocomposite Laminates at Elevated Temperature

To deal with the stringent operational demands the aerospace structural materials of light weight Aluminum alloy 2024 sheets and plies of carbon fibers reinforced thermoplastic matrix PEEK were used to sustain at least 80% of their mechanical properties at elevated temperature. The addition of nanoparticles SiO2 can enhance the composite laminate strength and stiffness. Also, Al 2024 sheets were treated by an anodic method of electroplating to increase surface roughness to achieve perfectly bonding with matrix PEEK. Then, the modified diaphragm curing process was adopted to make the innovative hybrid Al/APC-2 hybrid nanocomposite laminates. Next, both static tensile and fatigue tests were conducted at elevated temperature to obtain the mechanical properties, lives and failure mechanisms to verify the improved features of hybrid specimens. From tensile tests the mechanical properties of Al/APC-2 [4Al/0/±45/90/2Al]s hybrid laminates at elevated temperature were obtained. Although there is a big drop at 150°C, the reduction in strength from RT to 125°C is generally not significant. The longitudinal stiffness is almost unchanged at elevated temperature. After cyclic tension-tension (T-T) tests, the positions of received S-N curves go downwards as temperature rising. No delaminations were found in both tests. If the applied stress normalized by the ultimate strength at corresponding temperature, the normalized S-N curves are closer with some curve positions reversed. Significant improvement of manufacturing and enhancement of mechanical properties in hybrid laminates were achieved finally.

Preparation of MWCNT/Carbon Fabric Reinforced Hybrid Nanocomposite and Examination of its Mechanical Properties

In our work we have prepared carbon fiber/epoxy composite and carbon fiber/carbon nanotube/epoxy hybrid nanocomposite laminates by hand laminating assisted by vacuumbag technology. During the production of the specimens we have encountered the viscosity increasing effect of nanotube filling, which we characterized by a viscosity test. The results of the test showed, that in the lowest shear rate range carbon nanotube filling can cause an increase of viscosity by three orders of magnitude, but also at higher shear rates the viscosity of the nanotube filled epoxy resin was ten times the viscosity of the unfilled resin. Mechanical properties of the composite and hybrid composite have been compared by tensile, bending and interlaminar shear tests. During the tensile tests AE signals have also been recorded. The fracture surfaces have been examined by SEM micrographs. The nanotube filling has decreased the tensile strength and the modulus of elasticity by 7-8 percent presumably indirectly, the bending properties didn’t change noticeably, but the interlaminar shear strength of the composite has increased by 15 percent thanks to nanotube filling of the matrix. The decrease of the delamination inclination of the hybrid composite has been affirmed both by the AE and SEM results.

Effect of nanoclay addition on vibration properties of glass fibre reinforced vinyl ester composites

This paper presents the experimental study of free vibration and damping characteristics of hybrid nanocomposite laminates by reinforcing short fibre chopped strand mat and organically modified montmorillonite clay (0, 1, 3 and 5 wt.%) in the vinyl ester matrix by hand lay-up technique. Theoretical study is also carried out to study the vibration and damping characteristics of hybrid nanocomposites. Dynamic result shows that the second phase nanoscale dispersion in the matrix and E-glass fibre significantly enhances the internal damping of hybrid composites.