Experimental investigation of the tensile and bending behavior of multi-axial warp-knitted fabric composites

2016 ◽  
Vol 88 (3) ◽  
pp. 333-344 ◽  
Author(s):  
Xiaoping Gao ◽  
Danxi Li ◽  
Wei Wu ◽  
Si Chen
Keyword(s):  
Volume Fraction ◽  
Orientation Distribution ◽  
Knitted Fabric ◽  
Fiber Volume ◽  
Molding Method ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Static Tensile ◽  
Bending Behavior ◽  
Warp Knitted Fabric

An experimental study was carried out on the tensile and bending behavior of multi-axial warp-knitted fabric composites. Five specimens reinforced with multi-axial warp-knitted fabric/epoxy were manufactured by a vacuum-assisted resin transfer molding method. Quasi-static tensile and three-point bending tests were carried out in a number of orientations relative to the stitching direction: quadriaxial, triaxial, biaxial (±45° and 0/90°) and unidirectional. The results of the tests revealed that the quadriaxial and biaxial (±45°) samples showed quasi-isotropic behavior, whereas the other laminates showed anisotropic behavior. The influence of fiber volume fraction and the orientation distribution of the constituent material on the tensile and bending behavior were also analyzed. The relationships between the stress and strain and the tensile and bending behavior of different multi-axial warp-knitted fabric composite were obtained by polynomial fitting.

Effect of Nesting of Fiber Bundles on Micro Fracture of Laminated Woven Fabric Composite

2002 ◽  
Author(s):  
Toshiko Osada ◽  
Asami Nakai ◽  
Hiroyuki Hamada
Keyword(s):  
Volume Fraction ◽  
Woven Fabric ◽  
Fiber Bundles ◽  
Fiber Volume ◽  
Woven Fabric Composites ◽  
Number Of Layers ◽  
Fabric Composite ◽  
Knee Point ◽  
Fabric Composites ◽  
Layer Increase

In laminated woven fabric composites, fiber bundles do not pack tightly because there are resin rich regions caused by crimp of fiber bundles. The fiber bundles in one layer are often fitted into the neighboring layer, which is called nesting. In this study, the effect of nesting by laminating on mechanical properties and micro fracture behavior of composites was investigated. Tensile testing of woven fabric composites with different number of layers and observation using optical microscopy were performed. With the increase of number of layers, nesting is more likely to occur, resulting in a decrease in thickness per layer increase in fiber volume fraction. This also lead to an increase in modulus and strength but a decrease in knee point stress. The locations at which cracks occurred were different in specimens with and without nesting.

Thermo-Mechanical Modeling of 3D Woven Fabric Composites Using Two-Step Homogenization Approach

2019 ◽  
Author(s):  
Nagappa Siddgonde ◽  
Anup Ghosh
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Woven Fabric ◽  
Fiber Volume ◽  
Woven Fabric Composites ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Matrix Properties ◽  
Homogenization Approach ◽  
3D Fea

Abstract A 3D finite element based Representative Volume Element (RVE) model has been developed to predict the thermo-mechanical properties of 3D orthogonal interlock woven fabric composites (OIWFC) and angle interlock woven fabric composite (AIWFC) using a two-step homogenization approach. The first step homogenization, micro-homogenization, deals with resin infiltration effect of yarn as a unidirectional continuous fiber with an assumption of 80 percent of fiber volume fraction based on initial fiber and matrix properties. The second step, meso-homogenization, predicts effective thermo-mechanical properties of 3D woven fabric composites based on effective yarn and matrix properties. The RVE analysis has been performed using 3D FEA method with periodic boundary conditions (PBCs). Further, a void study has been performed considering the influences of void on thermo-mechanical properties of the 3D woven fabric composite. It is noted that the influence of void contents plays a significant role in predicting the thermo-mechanical properties of the 3D WFC. The thermo-mechanical properties gradually decrease with an increase of void contents. Studies have been carried out considering the same fiber volume fractions in both 3D WFC models. An AIWFC model predicts higher values of thermo-mechanical constants than OIWFC model.

Effective Transverse Electrical Permittivities of Plain Weave, Twill Weave and Satin Fabric Composites

1995 ◽  
Vol 411 ◽  
Author(s):  
T.-W. Chou ◽  
Q-G. Ning
Keyword(s):  
Volume Fraction ◽  
Effective Properties ◽  
Dielectric Behavior ◽  
Analytical Prediction ◽  
Fiber Volume ◽  
Plain Weave ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Electrical Permittivity ◽  
Twill Weave

ABSTRACTThis paper reports the analytical prediction of effective transverse electrical permittivities of plain weave, twill weave, 4-harness irregular satin, as well as 5-harness and 8-harness satin fabric composites with lossy constituents. Analytical solutions of the effective properties are presented. Numerical examples are given to illustrate the effects of fiber volume fraction and fabric architecture on the composite effective transverse dielectric behavior. Key words: electrical permittivity, plain weave, twill weave, satin weave, fabric composite, analytical solution.

scholarly journals Deep Drawing of Plain Weft-Knitted Fabric Composites: Part 1.: Cup Height Analysis

1999 ◽  
Vol 8 (6) ◽  
pp. 096369359900800 ◽  
Author(s):  
T.C. Lim ◽  
S. Ramakrishna ◽  
H.M. Shang
Keyword(s):  
Deep Drawing ◽  
Shell Height ◽  
Knitted Fabric ◽  
Fabric Structure ◽  
Weft Knitted Fabric ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Good Agreement

Previous investigations on forming of plain weft-knitted fabric composite sheets show the ease of stretching due to fabric loop straightening. Pure dependence on stretching alone, however, sets the limit to which the shell height can be further increased. Recent deep drawn knitted fabric composites give greater cup height in comparison to stretch formed cup. In this paper a method of predicting the achievable cup height is proposed with due consideration to the fabric structure and tool dimensions. Comparison between the theoretical and experimental cup height shows good agreement.

The Effects of Fiber Volume Fraction on the Vibration Damping Characteristics of Three-Layer-Connected Biaxial Weft Knitted Fabric Reinforced Composite Materials

2012 ◽  
Vol 602-604 ◽  
pp. 49-52
Author(s):  
Jing Xue Liu ◽  
Jia Lu Li
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Damping Ratio ◽  
Vibration Damping ◽  
Knitted Fabric ◽  
Vibration Modes ◽  
Fiber Volume ◽  
Damping Behavior ◽  
Weft Knitted Fabric ◽  
Vibration Parameters

The paper presents an analysis of the vibration damping properties of three-layer-connected biaxial weft knitted fabric (TBWK), which are constituted of carbon fibers as inserted yarns and polyester yarns as knitted yarns impregnated in an epoxy matrix with resin transfer molding (RTM) technique. Damping parameters were investigated using beam test specimens and an impulse technique. Several vibration parameters were varied to characterize the damping behavior in different amplitudes, natural frequencies and vibration modes. The results obtained show that the damping ratio of TBWK composites decreases with the increasing of fiber volume fraction in all the three vibration modes. The vibration test also indicates that the natural frequency of the TBWK composites increases with the increasing of fiber volume fraction (Vf) in all the three modes.

Analysis of Bending Behavior of Laminated Composite Beam

2015 ◽  
Vol 786 ◽  
pp. 421-425
Author(s):  
R. Arravind ◽  
M. Saravanan ◽  
K. Balasubramanian
Keyword(s):  
Composite Beam ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Laminated Composite ◽  
Layered Composite ◽  
Fiber Volume ◽  
Bottom Side ◽  
Bending Behavior ◽  
Laminated Composite Beam ◽  
The Impact

This paper discusses about the impact of fiber volume fraction on the bending behavior of a laminated composite beam. A two layered composite beam with upper layer made of glass fiber epoxy resin and reinforced with Kevlar at the bottom side of the beam is modeled and structural analysis is carried out. The analysis shows that the tensile strength increases with increase in fiber volume fraction. The compression strength decreases with increase in fiber volume fraction in the upper fiber where as increases in the bottom fiber and the obtained results are correlating with the experimental and analytical studies.

scholarly journals Experimental and Numerical Simulation of the Tensile Behaviour of a Biaxial Warp-knitted Composite

2018 ◽  
Vol 26 (6(132)) ◽  
pp. 71-76
Author(s):  
Xiaoping Gao ◽  
Xiaori Yang ◽  
Danxi Li ◽  
Yonggui Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Dynamic Mechanical Properties ◽  
Tensile Behaviour ◽  
Knitted Fabric ◽  
Static Tensile ◽  
Warp Knitted Fabric ◽  
The Finite Element Model ◽  
Meso Scale

In this paper a composite reinforced with biaxial warp-knitted fabric and epoxy resin was manufactured by applying vacuum assisted resin transfer moldings (VARTM). The quasi- -static tensile behaviour was experimentally tested in 0° and 90° directions, respectively. A finite element model of biaxial warp-knitted composites was developed on a meso-scale. The tensile behaviour of the composites was numerical simulated and compared with the experimental results. It showed that there is an approximate agreement between experimental and numerical results. There are maximum errors sum of squares of 14.52% and 33.29%. The finite element model of biaxial warp-knitted composites has higher accuracy, which can be used to study the static and dynamic mechanical properties.

Automated RVE computations for evaluation of microdamage initiation in structural stitched non-crimp fabric composites

2020 ◽  
Vol 54 (30) ◽  
pp. 4751-4771
Author(s):  
Gerrit Pierreux ◽  
Danny Van Hemelrijck ◽  
Thierry J Massart
Keyword(s):  
Cross Sections ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Direction ◽  
Fiber Volume ◽  
Damage Initiation ◽  
Processing Step ◽  
Fabric Composites ◽  
Out Of Plane ◽  
Generate Unit

This contribution presents an approach to generate unit-cell models of structural stitched non-crimp fabric composites. Resin-rich regions and out-of-plane undulations caused by the stitching yarn are represented by initially straight discretised lines, while the stitching yarn is represented initially by a single discretised line which can be transformed into a multi-line configuration to model stitch cross-section variations. The discretised lines are shaped by geometrical operations with a contact treatment and boundary conditions being used to account, respectively, for line interactions and to control the shape of the bottom and top surfaces of each lamina respectively. A fiber-reinforced distorted zone with local variations in fiber volume fraction and fiber direction is modelled in cross-sections of the lamina in a post-processing step. Models for different stacking sequences and stitching parameters are then automatically generated and subsequently being in the stiffness calculation and damage initiation assessment using finite element based mechanical simulations.

Sign in / Sign up

Export Citation Format

Share Document