Characterization of Fiber Volume Fraction Gradients in Composite Laminates

2008 ◽  
Vol 42 (5) ◽  
pp. 447-466 ◽  
Author(s):  
Michael T. Cann ◽  
Daniel O. Adams ◽  
Claudio L. Schneider
Keyword(s):  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume

Pressurized Infusion: A New and Improved Liquid Composite Molding Process

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
M. Akif Yalcinkaya ◽  
Gorkem E. Guloglu ◽  
Maya Pishvar ◽  
Mehrad Amirkhosravi ◽  
E. Murat Sozer ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Compaction Pressure ◽  
External Pressure ◽  
Void Content ◽  
Liquid Composite Molding ◽  
Molding Process ◽  
Fiber Volume

Vacuum-assisted resin transfer molding (VARTM) has several inherent shortcomings such as long mold filling times, low fiber volume fraction, and high void content in fabricated laminates. These problems in VARTM mainly arise from the limited compaction of the laminate and low resin pressure. Pressurized infusion (PI) molding introduced in this paper overcomes these disadvantages by (i) applying high compaction pressure on the laminate by an external pressure chamber placed on the mold and (ii) increasing the resin pressure by pressurizing the inlet resin reservoir. The effectiveness of PI molding was verified by fabricating composite laminates at various levels of chamber and inlet pressures and investigating the effect of these parameters on the fill time, fiber volume fraction, and void content. Furthermore, spatial distribution of voids was characterized by employing a unique method, which uses a flatbed scanner to capture the high-resolution planar scan of the fabricated laminates. The results revealed that PI molding reduced fill time by 45%, increased fiber volume fraction by 16%, reduced void content by 98%, improved short beam shear (SBS) strength by 14%, and yielded uniform spatial distribution of voids compared to those obtained by conventional VARTM.

Bending Properties of Four-Layer Biaxial Weft Knitted Fabric Reinforced Composite Materials

2012 ◽  
Vol 182-183 ◽  
pp. 89-92
Author(s):  
Liang Sen Liu ◽  
Ye Xiong Qi ◽  
Jia Lu Li
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Volume Fraction ◽  
Bending Properties ◽  
Fiber Volume ◽  
Reinforced Composite ◽  
Weft Knitted Fabric ◽  
Bending Load

In this paper, a kind of composite laminates whose reinforcement is four-layer biaxial weft knitted (FBWK)fabric made of carbon fiber as inserted yarns has been made. The composite laminates have been impregnated with epoxy resin via resin transfer molding (RTM) technique. The samples of the experiments have been made from the composite laminates. The bending properties of the FBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The results show that the bending strength of this kind of composites increases with the fiber volume fraction increasing. The bending strength of FBWK reinforced composites with fiber volume fraction of 52% can reach 695.86 MPa. And the relationship between bending load and deflection is obviously linear.

The Characterization of Discontinuous Carbon Fiber Mat Reinforced Epoxy Composite Materials

2015 ◽  
Vol 1110 ◽  
pp. 77-81
Author(s):  
Eun Soo Lee ◽  
Daniel Buecher ◽  
Si Hoon Jang ◽  
Dae Young Lim ◽  
Ki Young Kim
Keyword(s):  
Carbon Fiber ◽  
Fiber Length ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Physical And Mechanical Properties ◽  
Void Content ◽  
Reinforced Composites ◽  
Fiber Volume ◽  
Fiber Fabric

The carbon fiber mat preforms are prepared by an air laid method with different fiber lengths of 10mm, 30mm and 50mm to characterize the resultant discontinuous composites. The composites are manufactured by a vacuum assisted resin infusion (VaRI) molding technique with the use of epoxy resins to investigate the effects of carbon fiber length on their physical and mechanical properties. The void content and thickness of the composites decrease with the increase in the fiber length at the same VaRI processing conditions. The tensile, flexural, impact properties of the composites are improved by increasing the fiber length in the textile preforms. By comparing with those of carbon fiber fabric reinforced composites, the discontinuous composites demonstrate the excellent performance in strength and modulus in spite of lower fiber volume fraction.

Pressure-controlled compaction characterization of fiber preforms suitable for viscoelastic modeling in the vacuum infusion process

2017 ◽  
Vol 51 (9) ◽  
pp. 1209-1224 ◽  
Author(s):  
Bekir Yenilmez ◽  
Baris Caglar ◽  
E Murat Sozer
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Compaction Rate ◽  
Vacuum Infusion ◽  
Viscoelastic Modeling ◽  
A Minor ◽  
Fiber Preforms ◽  
Vacuum Infusion Process

A woven fabric’s compaction in the vacuum infusion process is characterized by applying an initial settling under a minor load, compaction, settling under a major load, decompaction and relaxation. The effects of compaction rate, relaxation pressure, wetting and debulking cycles are all investigated. Although wetting helps by increasing fiber volume fraction insignificantly, its contribution is more significant during debulking cycles by increasing the fiber volume fraction to 57.4% as compared to 55.4% for the debulked dry specimens. Recovery during decompaction is much less than the deformation during compaction, and thinning/thickening of the specimens with time under constant pressure, so called settling/relaxation pressures, indicates that fabric specimens are not elastic materials, but viscoelastic. The experimental data of this study will be valuable to compare different viscoelastic and elastic compaction models in our next study.

Microstructural Characterization of “New” 2.5D Woven Reinforcement Materials

2011 ◽  
Vol 217-218 ◽  
pp. 97-100
Author(s):  
Dian Tang Zhang ◽  
Ying Sun ◽  
Wei Hai ◽  
Li Chen ◽  
Ning Pan
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Fiber Volume ◽  
3D Images ◽  
Geometry Model ◽  
Convex Lens ◽  
Woven Reinforcement ◽  
Prediction Of Mechanical Properties

Based on the photographic observation and analysis of different cross section of the materials, it is found that both the section of normal and warp yarns are rectangular in shape, the sections of weft yarns are the convex lens in shape, the weft and normal yarns are kept straight along their directions, the warp yarns are wavy. 3D images and geometry model of normal yarns reinforced 2.5D woven materials are established. This model can be used to calculate the fiber volume fraction of each yarn system. Compared with the experimental data, the computational results show excellent agreement. The work will lay the foundation for prediction of mechanical properties.

scholarly journals Simulation and characterization of circular hexagonal braiding fabricstructure

2020 ◽  
Vol 71 (01) ◽  
pp. 23-27
Author(s):  
LI ZHENGNING ◽  
LYU HAICHEN ◽  
CHEN GE ◽  
KO FRANK
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
State Of The Art ◽  
Fiber Volume ◽  
Fabric Structure ◽  
Stitch Length ◽  
Spatial Coordinates ◽  
Fabric Structures ◽  
Initial Arrangement

Hexagonal braiding technology is a kind of state-of-the-art braiding method, which uses hexagonal horngears to driveyarn carriers and make yarns intertwined into fabrics. In terms of hexagonal braiding principles, the braiding parameterslike initial arrangement of yarn carriers, yarn number and horngears sequence were defined, and then the movementpaths of yarn carriers in hexagonal braiding process and stitch length were obtained, which could be converted intocoordinates on the xoy plane and the coordinates along z-axis. In that case, a group of spatial coordinates were got tocreate the yarn trajectories and fabric structures in Matlab. And then, B-spline curve was utilized to fit the yarntrajectories. Considering the compactness of hexagonal fabric, the coordinates conversion algorithm and conversionmatrix were utilized to optimize the fabric structure, so a more compact fabric structure was established. The braidingangle variation and volume fraction of fabric showed that after coordinates conversion the braiding angles became morestable than original fabric model, and the fiber volume fraction of fabric was improved too. So the fabric structure modelwas available to describe hexagonal fabric structure, which can offer the reference for the further study on properties ofhexagonal braiding technology and application of hexagonal braided fabric

scholarly journals Research on damping performance and strength of the composite laminate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bao Zhang ◽  
Zhi Li ◽  
Huawei Wu ◽  
Jinquan Nie
Keyword(s):  
Tensile Strength ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Test Method ◽  
Damping Capacity ◽  
Fiber Volume ◽  
Air Damping

AbstractIn this paper, the influence of E-glass fiber volume fraction and laying angle on the damping and strength of composite laminates was comprehensively analyzed. By increasing the fiber laying angle and reducing the glass fiber volume fraction, the damping capacity of the composite laminate was increased, but the tensile strength of the laminate was reduced; By reducing the fiber laying angle and increasing the glass fiber volume fraction, the tensile strength of the composite laminate was increased, but the damping characteristics of the laminate was reduced. In addition, in the damping experiment of composite laminates, in order to avoid the influence of external damping sources, the vacuum non-contact damping test method was adopted in this paper, and the influence of air damping on the damping experiment results of composite laminates was comparatively analyzed. The results of comparative experiments showed that air damping had a very obvious influence on the damping of composite laminates, especially when the damping of composite laminates was small, the influence of air damping would be greater.

Composite Laminates under Hygrothermal Environment

2015 ◽  
Vol 769 ◽  
pp. 312-315
Author(s):  
Eva Kormanikova ◽  
Kamila Kotrasova
Keyword(s):  
Composite Laminates ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Material Stiffness ◽  
Hygrothermal Effect ◽  
Stiffness Properties ◽  
Empirical Relations ◽  
The Matrix ◽  
Hygrothermal Environment

The hygrothermal effect is introduced by using empirical relations for degrading the material stiffness properties of the matrix. A parametric study is conducted by varying the fiber volume fraction and the fiber orientation of the angle plies in the laminate. It is possible to minimize the environmental effect by judiciously selecting the laminate configuration.

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