Evaluation of fiber volume fraction of kenaf-coir-epoxy based green composite by finite element analysis

Author(s):  
Shikha Parashar ◽  
V.K. Chawla
Author(s):  
Seyed Hamid Reza Sanei ◽  
Randall Doles ◽  
Tyler Ekaitis

This paper addresses the effect of microstructure uncertainties on elastic properties of nanocomposites using finite element analysis (FEA) simulations. Computer-simulated microstructures were generated to reflect the variability observed in nanocomposite microstructures. The effect of waviness, agglomeration, and orientation of carbon nanotubes (CNTs) were investigated. Generated microstructures were converted to image-based 2D FEA models. Two hundred different realizations of microstructures were generated for each microstructure type to capture the stochastic response. The results confirm previously reported findings and experimental results. The results show that for a given fiber volume fraction, CNTs orientation, waviness, and agglomeration result in different elastic properties. It was shown that while a given microstructural feature will improve the elastic property, it will increase the variability in the elastic properties.


2007 ◽  
Vol 546-549 ◽  
pp. 1555-1558
Author(s):  
Chun Jun Liu ◽  
Yue Zhang ◽  
Da Hai Zhang ◽  
Zhong Ping Li

In this paper the composite fracture process has been simulated via the finite element method. A micromechanics model was developed to predict the stress-strain response of a SiO2f/ SiO2 composite explicitly accounting for the local damage mechanisms such as fiber fracture and interfacial debonding. The effects of interfacial strength and fiber volume fraction on the toughness of fiber-reinforced ceramic matrix composites were investigated. The results showed that the composite failure behaviors correlated with the interface strength, which could achieve an optimum value for the elevation of the composite toughness. The increase of fiber volume fraction can make more toughening contributions.


2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Iman Eslami Afrooz ◽  
Andreas Öchsner

Finite element analysis has been employed to investigate the effect of carbon nanotubes (CNTs) distribution on the thermal conductivity of composite materials. Several kinds of representative volume elements (RVEs) employed in this study are made by assuming that unidirectional CNTs are randomly distributed in a polymer matrix. It is also assumed that each set of RVEs contains a constant fiber volume fraction and aspect ratio. Results show that randomness—the way in which fibers are distributed inside the matrix—has a significant effect on the thermal conductivity of CNT composites. Results of this study were compared using the analytical Xue and Nan model and good agreement was observed.


2011 ◽  
Vol 250-253 ◽  
pp. 3975-3982 ◽  
Author(s):  
Ji Sheng Qiu

Steel fiber concrete multi-ribbed composite slab system includes material composite and structure type composite, which has good mechanical and thermal insulation properties. This paper presents an assessment of the structure investigated using three-dimensional nonlinear finite elemental analysis. The analysis firstly has focused on solving the constitutive relation of the materials and the effect of steel fiber to determine the finite element simulation. Moreover nonlinear finite element analysis for the mechanical properties of the whole process on the composite structure system has been presented in this paper, and by changing the fiber volume fractionvf(0%, 1%, 2% and 3%) the parameter has been discussed. The analysis results show that stress distributions of the structure are close for different concrete strength and steel fiber volume fraction before formation of the plastic hinge lines of the upper edges. When the structure began to crack and the plastic hinge lines of upper edge gradually formed, due to the influence of the redistribution of internal forces, the steel fiber volume fraction has significant impact for the mechanic behavior of the structure. In addition, the steel fiber volume fraction on the developing and distribution of the cracks has little effect. This analysis method and results for the steel fiber concrete multi-ribbed composite structure can provide some valuable references for the structure research and application.


Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Volkan Coşkun ◽  
Bülent Acar ◽  
Tarık Olğar

Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture the pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition and material properties of matrix and fiber. The designed ideal pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, the effect of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance was investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the layer-by-layer thickness and fiber volume fraction variation. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization test was performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.


2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Bülent Acar ◽  
Volkan Coşkun ◽  
Tarık Olğar

Abstract Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition, and material properties of matrix and fiber. The designed pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, effects of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance were investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the thickness of each layer separately and variation of fiber volume fraction between the layers. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization tests were performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.


2018 ◽  
Vol 5 (8) ◽  
pp. 16800-16806 ◽  
Author(s):  
Y.J. Nithiya Sandhiya ◽  
M.M. Thamizharasan ◽  
B.V. Ajay Subramanyam ◽  
K.S. Vijay Sekar ◽  
S. Suresh Kumar

2008 ◽  
Vol 33-37 ◽  
pp. 477-482 ◽  
Author(s):  
Xi Tao Zheng ◽  
Jian Feng Zhang ◽  
Fan Yang ◽  
Ya Nan Chai ◽  
Ye Li

To quantify the effect of structural through-thickness reinforcement in foam core sandwich composite panels, an experimental study was carried out which included three-point bending tests, core shear tests, flatwise tensile and compression tests, as well as edgewise compression tests. Standard test procedures based on ASTM guidelines are followed to test the behavior of the stitched panels with reinforcement at 90 degree orientation with respect to the sandwich faces. The test specimens were manufactured by using polyurethane foam Rohacell 71 IG and carbon fiber reinforced composite facesheets. The dry perform facesheets and foam core were then assembled in a dry lay-up already stitched. Kevlar 29 yarn was used to stitch both sets of panels. The results showed a significant effect of the stitching on the in-plane Young’s modulus which was attributed to local displacements of the in-plane fibers and changes in the fiber volume fraction. Stitching of sandwich panels significantly increases the maximum failure loads under flexure, core shear, flatwise tensile, flatwise compression, and edgewise compression loading. A finite element based unit-cell model was developed to estimate the elastic constants of structurally stitched foam core sandwich composite panels taking into consideration the yarn diameter, the stitching pattern and direction as well as the load direction. Depending on these parameters, local changes of the fiber volume fraction as well as regions with undisturbed and disturbed fiber orientations within the laminate plies are taken into account. A good match between the finite element modeling and the experimental data was obtained. The present work should be considered as a step towards developing a more sophisticated numerical model capable of describing mechanical behavior of sandwich structures.


2011 ◽  
Vol 341-342 ◽  
pp. 183-188
Author(s):  
Bao Zhong Sun ◽  
Kun Luan ◽  
Bo Hong Gu ◽  
Xiao Meng Fang ◽  
Jia Jin Zhang

Green composite made from ramie fabric and polypropylene (PP) is a kind of recyclable and environmental friendly material. Ramie fiber tows have relatively good mechanical properties comparing with other bast fibers, and hence the fabric woven by ramie yarn shows excellent in-plane mechanical behaviors. PP can be fully recovered and recycling used for its thermoplastic character. Ramie fabrics reinforced by PP have better shape formability and maintenance. In this paper, we proposed a plain weave in sample dobby loom, and reinforced four laid-layers together by PP particle through hot pressing. The mechanical behaviors of the ramie-PP composite were tested by MTS-810 Material Testing System in weft and warp directions separately which were essential parameters to the following topology optimization in finite element analysis (FEA) software. A body of eco-power automobile consisting of shell and chassis was original designed in Pro/E® Wildfire 5.0. For the chassis is the main bearing structure, it is an important part in the eco-power automobile body and was chosen to be topology optimized. Fiber volume fraction and structure optimization of the chassis model are evaluated and simulated to guide the material formation of manufacture progress.


2019 ◽  
Vol 801 ◽  
pp. 65-70
Author(s):  
Jian Hong Gao ◽  
Xiao Xiang Yang

RVE combined with finite element analysis (FEA) is a very popular method to predict the mechanical property of the composite reinforced by short fibers. In the conventional method, generally the “tie” approach is used. By this method, the FE model with high fiber aspect ratio can not be achieved and the non-convergence of the numerical calculation may appear because of the complex mesh. The embedded element techinique is considered to be a replaceable method . Using this method, the mechanical behavior of composite with high fiber aspect ratio would be simulated. Therefore, in this study, the 3D solid element was employed for the FE model with multi cylinder particles. The comparisions of the Mise stress and the displacement between the embedded and conventional method indicate that compared with the stress transfer, the simulated result of composite stiffness is more accurate. In addition, the effects of model size, fiber orientated angle, fiber volume fraction and fiber aspect ratio were investigated. The numerical results were compared with the Mori-Tanaka model and the good agreements verify the applicability of the embedded element technique we studied in this paper.


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