Influences of graphene oxide addition on mechanical properties of aramid fiber reinforced composites

2019 ◽  
Vol 9 (6) ◽  
pp. 578-586 ◽  
Author(s):  
Xiaoma Ding ◽  
Ziling Zhang ◽  
Haijuan Kong ◽  
Mengmeng Qiao ◽  
Zhifeng Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Tensile Modulus ◽  
Aramid Fiber ◽  
Matrix Phase ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Stress Concentrations ◽  
Test Standards

In this paper, the graphene oxide (GO) was prepared by the modified Hummers' method in advance, and the obtained GO was used as a kind of filler added into the epoxy resin (EP) system (including the EP and corresponding curing agent) with different contents (relative to the total weight of the GO-EP system hybrid) ranging from 0.1 to 0.4 wt% to improve the mechanical properties of the aramid fiber reinforced composites (AFRC) through the autoclave forming technology. Then, a series of mechanical properties of the AFRC were measured according to the relevant test standards. Results showed that partial mechanical properties of the AFRC, especially the interlayer property, changed with the different contents of GO. Nevertheless, the tensile strength and tensile modulus of the AFRC presented no obvious changes for different contents of GO. Overall, the matrix phase EP system modified by the GO played an important role in the interlayer toughness of AFRC without reducing its tensile property. This was because the addition of the small amount of GO could prevent the generation of stress concentrations caused by the gaps between the reinforcing phase aramid fibers (AFs) and matrix phase EP system owing to their poor bondings.

Evaluation of mechanical properties of fiber reinforced composites filled with hollow spheres: A micromechanics approach

2020 ◽  
pp. 002199832094964
Author(s):  
Mojde Biarjemandi ◽  
Ehsan Etemadi ◽  
Mojtaba Lezgy-Nazargah
Keyword(s):  
Mechanical Properties ◽  
Elastic Constants ◽  
Volume Fraction ◽  
Hollow Spheres ◽  
Matrix Phase ◽  
Fiber Reinforced Composites ◽  
Fiber Direction ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
The Matrix

Recent researches show that the embedment of hollow spheres in the matrix phase of composite materials improves the strength of these structures against crack propagations. Rare studies are reported for calculating equivalent elastic constants of fiber reinforced composites containing hollow spheres. In this paper, the effects of hollow spheres on mechanical characteristics of fiber reinforced composite are studied for the first time. To achieve this aim, a micromechanics based finite element method is employed. Representative volume elements (RVEs) including hollow spheres with different radius, thickness and volume fraction of hollow spheres, are modeled by using 3D finite elements. The equivalent elastic constants are calculated through homogenization technique. The results are compared with available experimental works. Good agreements find between two sets of results. Also, the volume fraction, number and thickness of hollow spheres as effective parameters on mechanical properties of composite were investigated. The results show the equivalent elastic properties increase with increasing the volume fraction and number of hollow spheres and decrease with increasing the number of hollow spheres. Furthermore, the equivalent Young’s modulus in transverse directions to the fiber direction and shear modulus of the composite increase with increasing the thickness of hollow spheres. As a final result, the presence of hollow spheres in the matrix phase generally increases the equivalent elastic constants without significant changes in the weight of structures.

scholarly journals The Effect of Stacking Sequence of Woven Bamboo on Mechanical Behavior of Fiber-Reinforced Composites

2021 ◽  
Vol 56 (2) ◽  
pp. 591-604
Author(s):  
Aidy Ali ◽  
Kannan Rassiah ◽  
M.M.H Megat Ahmad
Keyword(s):  
Mechanical Properties ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
Construction Materials ◽  
Tensile Modulus ◽  
Fiber Reinforced Composites ◽  
Stacking Sequence ◽  
Reinforced Composites ◽  
Fiber Reinforced

Natural fiber-reinforced composites are necessary to increase the use of polymer composite technology. This study investigates a specific type of bamboo species named Gigantochloa Scortechinii (Buluh Semantan), collected from the Bukit Larang Village in Melaka, Malaysia. Bamboo strips with average dimensions of 300 mm x 5 mm x 0.5 mm were weaved in plain-woven bamboo and divided into 2 to 6 laminate layers through 6 layers of E-glass epoxy subjected to the hand lay-up process to produce the hybrid composite. The hybrid composites were prepared in a stacking sequence of plain-woven bamboo and were characterized in their mechanical properties. The behaviors of the tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength improved in the 2-layer laminated hybrid sequences. Still, the opposite trend was observed for the hardness value with the 6-layer laminated mixed sequences. The morphology scanning electron microscopy (SEM) results supported the findings of the mechanical properties, which demonstrated the interaction between the EP and fibers with the selected stacking sequence. The works give sound basis decisions to engineers to apply the Bamboo laminated composites in construction materials and building decoration.

Sulfone-functionalized poly(p-phenylene terephthalamide) copolymer fibers with improved interfacial adhesion to epoxy matrices

2021 ◽  
pp. 095400832110089
Author(s):  
Ting Li ◽  
Zengxiao Wang ◽  
Hao Zhang ◽  
Yutong Cao ◽  
Zuming Hu ◽  
...  
Keyword(s):  
Interfacial Adhesion ◽  
Interfacial Shear Strength ◽  
Aramid Fiber ◽  
Fiber Reinforced Composites ◽  
Epoxy Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Regular Arrangement ◽  
Epoxy Matrices ◽  
Polymerization Conditions

The poor interfacial adhesion of aramid fiber and matrix limits the application of the final composites. In this study, a series of the sulfone-functionalized poly( p-phenylene terephthalamide) (SPPTA) copolymers were satisfactorily synthesized and the effects of polymerization conditions (contents of the additional monomer and the cosolvent LiCl, molar concentration and ratio of the monomer, reaction temperature and time) on the molecular weight of the copolymer were discussed. The introduction of the sulfone group in aromatic polyamides not only increased the polarity of poly( p-phenylene terephthalamide) (PPTA) but destroyed the regular arrangement of the molecular chains, which greatly improved the surface free energy and the solubility of the polymers in organic solvents. The polymer maintained excellent thermal and interfacial properties. Compared with the PPTA fiber/epoxy composites, the interfacial shear strength (IFSS) of SPPTA fiber-reinforced epoxy composites reached 43.5 MPa, with a significantly enhancement of 20.8%, implying that the study provided an effective method to achieve highly interfacial adhesion of aramid fiber-reinforced composites.

scholarly journals EFFECTS OF POROSITY ON ULTRASONIC CHARACTERISTIC PARAMETERS AND MECHANICAL PROPERTIES OF GLASS FIBER REINFORCED COMPOSITES

2012 ◽  
Vol 06 ◽  
pp. 646-651 ◽  
Author(s):  
Wen Ma ◽  
Fushun Liu
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Attenuation ◽  
Ultrasonic Inspection ◽  
Fiber Reinforced Composites ◽  
Metallographic Analysis ◽  
Void Content ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Characteristic Parameters ◽  
Distribution Shape

Voids are inevitable in the fabrication of fiber reinforced composites and have a detrimental impact on mechanical properties of composites. Different void contents were acquired by applying different vacuum bag pressures. Ultrasonic inspection and ablation density method were adopted to measure the ultrasonic characteristic parameters and average porosity, the characterization of voids' distribution, shape and size were carried out through metallographic analysis. Effects of void content on the tensile, flexural and interlaminar shear properties and the ultrasonic characteristic parameters were discussed. The results showed that, as vacuum bag pressure went from -50kPa to -98kPa, the voids content decreased from 4.36 to 0.34, the ultrasonic attenuation coefficient decreased, but the mechanical strengths all increased.

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