3D layer-to-layer orthogonal interlock woven composites under monotonic loading: Multiscale modeling

2017 ◽  
Vol 36 (17) ◽  
pp. 1263-1285 ◽  
Author(s):  
M Muthukumar ◽  
J Prasath ◽  
S Sathish ◽  
G Ravikumar ◽  
YM Desai ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Multiscale Modeling ◽  
Cross Section ◽  
Composite Structure ◽  
Volume Fraction ◽  
Woven Composites ◽  
Woven Composite ◽  
Fiber Volume ◽  
Element Analysis ◽  
Unit Cells

Multiscale modeling of 3D layer-to-layer orthogonal interlock woven composite structure for elastic and strength behavior is presented. Due to the inherent nature of weaving, 3D woven composites can be represented by repetitive unit cells at the meso level. The present study focuses on identifying different types of repetitive unit cells considering both the geometry and the boundary conditions. For a typical 3D layer-to-layer orthogonal interlock woven composite, there are eight types of meso repetitive unit cells taking into account both the geometry and the boundary conditions. Additionally, for a practical situation, fiber volume fraction (Vf) in the impregnated strand is not uniform throughout the cross-section. In other words, Vf would be different for different micro repetitive unit cells. The properties of the macro structure, i.e. the 3D woven composite structure has been determined by applying periodic boundary conditions at micro and meso levels and iso-strain conditions at the macro level using finite element analysis. The continuity between the blocks is provided by merging the nodes in the intersection regions. The effect of different Vf at different locations in the transverse cross-section of the strand on the elastic and the strength properties of 3D layer-to-layer woven composite structure is presented.

Correlation of Thermal Conductivities of Unidirectional Fibrous Composites Using Local Fractal Techniques

1991 ◽  
Vol 113 (4) ◽  
pp. 788-796 ◽  
Author(s):  
R. Pitchumani ◽  
S. C. Yao
Keyword(s):  
Cross Section ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Flow Direction ◽  
Fractal Dimensions ◽  
Unit Cell ◽  
Small Range ◽  
Fiber Volume ◽  
Unit Cells ◽  
Traditional Approaches

The arrangement of fibers strongly influences heat conduction in a composite. Traditional approaches using unit cells to describe the fiber arrangements work well in the case of ordered arrays, but are not useful in the context of disordered arrays, which have been analyzed in the literature by statistical means. This work presents a unified treatment using the tool of local fractal dimensions (although, strictly speaking, a composite cross section may not be an exact fractal) to reduce the geometric complexity of the relative fiber arrangement in the composite. The local fractal dimensions of a fibrous composite cross section are the fractal dimensions that it exhibits over a certain small range of length scales. A generalized unit cell is constructed based on the fiber volume fraction and local fractal dimensions along directions parallel and transverse to the heat flow direction. The thermal model resulting from a simplified analysis of this unit cell is shown to be very effective in predicting the conductivities of composites with both ordered as well as disordered arrangement of fibers. For the case of square packing arrays, the theoretical result of the present analysis is identical to that of Springer and Tsai (1967).

Mechanical behavior of unidirectional composites with hexagonal and uneven distribution of fibers in the transverse cross-section

2018 ◽  
Vol 52 (22) ◽  
pp. 2985-3000 ◽  
Author(s):  
M Muthukumar ◽  
J Prasath ◽  
YM Desai ◽  
NK Naik
Keyword(s):  
Finite Element Analysis ◽  
Cross Section ◽  
Volume Fraction ◽  
Transverse Cross Section ◽  
Strength Properties ◽  
Unidirectional Composite ◽  
Uneven Distribution ◽  
Element Analysis ◽  
Unit Cells ◽  
Hexagonal Arrangement

Uneven distribution of fibers can adversely affect the mechanical behavior of unidirectional composites. A micromechanical model based on finite element analysis is presented to evaluate elastic and strength properties of such composites under normal loading. Analysis starts with identification of micro unit cells/micro repetitive unit cells and/or representative volume elements. Because of uneven distribution/random distribution of the fibers, fiber volume fraction can be different for different micro unit cells present at different locations in the transverse cross-section of the unidirectional composite. Configuration of the micro unit cell is worked out at the outset considering the fiber distribution having the hexagonal arrangement, but with different volume fraction at different locations. For such micro unit cells, elastic and strength properties are obtained based on finite element analysis starting with the elastic and strength properties of fiber and matrix. With the properties obtained for different micro unit cells, elastic and strength properties of the unidirectional composite with micro unit cells having hexagonal arrangement of fibers with different volume fraction at different locations in the transverse cross-section are determined. Further, elastic and strength properties are evaluated for micro unit cells with uneven distribution of fibers in the transverse cross-section.

Prediction of internal geometry and tensile behavior of 3D woven solid structures by mathematical coding

2021 ◽  
pp. 152808372110013
Author(s):  
Vivek R Jayan ◽  
Lekhani Tripathi ◽  
Promoda Kumar Behera ◽  
Michal Petru ◽  
BK Behera
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Areal Density ◽  
Woven Fabrics ◽  
Tensile Behavior ◽  
Geometrical Parameters ◽  
Fiber Volume ◽  
Acceptable Error ◽  
Internal Geometry ◽  
Unit Cells

The internal geometry of composite material is one of the most important factors that influence its performance and service life. A new approach is proposed for the prediction of internal geometry and tensile behavior of the 3 D (three dimensional) woven fabrics by creating the unit cell using mathematical coding. In many technical applications, textile materials are subjected to rates of loading or straining that may be much greater in magnitude than the regular household applications of these materials. The main aim of this study is to provide a generalized method for all the structures. By mathematical coding, unit cells of 3 D woven orthogonal, warp interlock and angle interlock structures have been created. The study then focuses on developing code to analyze the geometrical parameters of the fabric like fabric thickness, areal density, and fiber volume fraction. Then, the tensile behavior of the coded 3 D structures is studied in Ansys platform and the results are compared with experimental values for authentication of geometrical parameters as well as for tensile behavior. The results show that the mathematical coding approach is a more efficient modeling technique with an acceptable error percentage.

On the Actuation Authority of Adaptive Sandwich Beam with Composite Actuators: Coupled Finite Element Analysis

2012 ◽  
Vol 585 ◽  
pp. 332-336 ◽  
Author(s):  
K. Venkata Rao ◽  
S. Raja ◽  
T. Munikenche Gowda
Keyword(s):  
Numerical Experiments ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Element ◽  
Fiber Volume ◽  
Element Analysis ◽  
Active Fiber ◽  
Macro Fiber Composite

A two noded active sandwich beam element is formulated by employing layerwise Timoshenko’s beam theory. Displacement continuity conditions are imposed between different layers of the sandwich. This element is used to model an adaptive sandwich beam with macro-fiber composite (MFC) as extension actuator and shear actuated fiber composite (SAFC) as shear actuator. Influence of thickness and volume fraction of the active fiber (PZT-5A and single crystal PMN-PT) in the composite actuators on the actuation performance of the sandwich beam is investigated. Based on several numerical experiments, it is found that the PMN-PT based shear actuators give maximum actuation authority for the volume fraction of the fibers in the range of 80%-85%, whereas in case of PZT-5A based shear actuators the actuation authority remains maximum for the fiber volume fractions 80% and above.

A New Unit Cell Concerned Realistic Geometry Structure of 3D Four Directional Braided Composite

2016 ◽  
Vol 860 ◽  
pp. 65-68
Author(s):  
Hai Jun Zhang ◽  
Chu Wei Zhou
Keyword(s):  
Volume Fraction ◽  
Unit Cell ◽  
Fiber Volume ◽  
The Real ◽  
Braided Composite ◽  
Packing Factor ◽  
Geometry Structure ◽  
Element Simulation ◽  
Unit Cells ◽  
Realistic Geometry

This paper represented a new unit cell of 3D four directional braided composite for mechanical properties calculation. There are three disadvantages of unit cells in most previous works such as the fiber volume fraction hard to touch the reality despite the packing factor is maximum 1, the yarns are curved subjectively which is far away from realistic geometry structure, a quantity of connected surfaces are neglected as the yarns are not match the real appearance. A new unit cell established based on the real manufacturing process and structure could improve these aspects in this work. The yarn in the unit cell was similar to the real one which was constructed by photos. The details at the conjoined position were also expressed thoroughly. The result of finite element simulation was in good agreement with the available experimental data.

Light-Weighting Design of Eco-Power Automobile Chassis Made from Green Composite and its Topology Optimization in FEA

2011 ◽  
Vol 341-342 ◽  
pp. 183-188
Author(s):  
Bao Zhong Sun ◽  
Kun Luan ◽  
Bo Hong Gu ◽  
Xiao Meng Fang ◽  
Jia Jin Zhang
Keyword(s):  
Topology Optimization ◽  
Volume Fraction ◽  
Testing System ◽  
Ramie Fiber ◽  
Mechanical Behaviors ◽  
Green Composite ◽  
Main Bearing ◽  
Fiber Volume ◽  
Element Analysis ◽  
Ramie Yarn

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.

scholarly journals Study on Retrofitting of RC Column Using Ferrocement Full and Strip Wrapping

2019 ◽  
Vol 5 (11) ◽  
pp. 2472-2485
Author(s):  
Balamuralikrishnan R. ◽  
M. Al Madhani ◽  
R. Al Madhani
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Volume Fraction ◽  
Single Layer ◽  
Longitudinal Reinforcement ◽  
Element Analysis ◽  
Rc Columns ◽  
Rc Column ◽  
Concrete Form ◽  
Wrapping Technique

Ferrocement is one of the cement-based composites used for retrofitting and rehabilitation among many applications. Ferrocement is one of the reinforced concrete form with lightweight and thin composite with durability and environmental resistant that strengthen the conventional RC columns to increase its strength and serviceability. This paper examines the performance of the ferrocement wrapping in RC columns experimentally with numerical simulation using ANSYS19. Totally sixteen number of RC column of size 150 mm × 150 mm in cross section and 450 mm in length were cast and tested in laboratory. Twelve are retrofitted columns with respect to volume fraction and wrapping technique. Six columns were retrofitted by full wrapping technique and six columns of strip wrapping technique. The remaining four columns are control columns in virgin condition to compare with the retrofitted columns. Concerning the volume fraction of each specimen, the number of pre-woven mesh layers were single layer, double layer and three layers. C30 concrete grade adopted in all specimens as per ACI Committee 211-1.91 with 4H8 longitudinal reinforcement and H6 of 75mm c/c ties. As the previous researchers examined the ferrocement and proved its efficiency. This study aims to examine the ferrocement in full and strip wrapping technique to compare their efficiency to increase the strength. Finite element analysis using ANSYS19 adopted to compare the experimental data with the numerical simulation. The results are analyzed and observed that the ferrocement has increased the confinement and strength of the RC columns. 

scholarly journals Efficiently, accurately, intelligently dissecting bamboo: characteristic of vascular bundle in Phyllostachys

2021 ◽  
Author(s):  
Haocheng Xu ◽  
Ying Zhang ◽  
Jiajun Wang ◽  
Tuhua Zhong ◽  
Xinxin Ma ◽  
...  
Keyword(s):  
Cross Section ◽  
Radial Distribution ◽  
Vascular Bundle ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Width Ratio ◽  
Vascular Bundles ◽  
Fiber Volume ◽  
Detection Model ◽  
Gradient Change

AbstractA comprehensive understanding of vascular bundles is the key to elucidate the excellent intrinsic mechanical properties of bamboo. This research aims to investigate the gradient distribution of fiber volume fraction and the gradient changes in the shape of vascular bundles along the radial axis in Phyllostachys. We constructed a universal transfer-learning-based vascular bundle detection model with high precision of up to 96.97%, which can help to acquire the characteristics of vascular bundles quickly and accurately. The total number of vascular bundles, total fiber sheath area, the length, width and area of fiber sheath of individual vascular bundles within the entire cross-section were counted, and the results showed that these parameters had a strongly positive linear correlation with the outer circumference and wall thickness of bamboo culms, but the fiber volume fraction (around 25.5 %) and the length-to-width ratio of the vascular bundles (around 1.226) were relatively constant. Furthermore, we layered the cross section of bamboo according to the wall thickness finely and counted the characteristics of vascular bundle in each layer. The results showed that the radial distribution of fiber volume fraction decreased exponentially, the radial distribution of the length-to-width ratio of vascular bundle decreased quadratically, the radial distribution of the width of vascular bundle increased linearly. The trends of the gradient change in vascular bundle’s characteristics were found highly consistent among 29 bamboo species in Phyllostachys.One sentence summaryA universal vascular bundle detection model can efficiently dissect vascular bundles in Phyllostachys, and the radial gradient change of vascular bundles in cross-section are found highly consistent.

scholarly journals A Comprehensive Study on the Mechanical Properties of Different 3D Woven Carbon Fiber-Epoxy Composites

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2765
Author(s):  
Qiaole Hu ◽  
Hafeezullah Memon ◽  
Yiping Qiu ◽  
Wanshuang Liu ◽  
Yi Wei
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Woven Composites ◽  
Thickness Direction ◽  
Woven Composite ◽  
Fiber Volume ◽  
3D Woven Composites ◽  
Accurate Comparison ◽  
3D Orthogonal Woven ◽  
Carbon Fiber Epoxy

In this work, the tensile, compressive, and flexural properties of three types of 3D woven composites were studied in three directions. To make an accurate comparison, three 3D woven composites are made to have the same fiber volume content by controlling the weaving parameters of 3D fabric. The results show that the 3D orthogonal woven composite (3DOWC) has better overall mechanical properties than those of the 3D shallow straight-joint woven composite (3DSSWC) and 3D shallow bend-joint woven composite (3DSBWC) in the warp direction, including tension, compression, and flexural strength. Interestingly their mechanical properties in the weft direction are about the same. In the through-thickness direction, however, the tensile and flexural strength of 3DOWC is about the same as 3DSBW, both higher than that of 3DSSWC. The compressive strength, on the other hand, is mainly dependent on the number of weft yarns in the through-thickness direction.

Finite Element Analysis of Interfacial Debonding Damage in Fiber-Reinforced Ceramic Matrix Composites

2007 ◽  
Vol 546-549 ◽  
pp. 1555-1558
Author(s):  
Chun Jun Liu ◽  
Yue Zhang ◽  
Da Hai Zhang ◽  
Zhong Ping Li
Keyword(s):  
Finite Element ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Interfacial Debonding ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Element Analysis

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.

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