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.

scholarly journals Formation of Resin-Rich Zones in Composites Processing

2010 ◽  
Vol 123-125 ◽  
pp. 543-546 ◽  
Author(s):  
Chen Song Dong ◽  
Tze Chiun Tsai
Keyword(s):  
Composite Structures ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Liquid Composite Molding ◽  
Fiber Volume ◽  
Factors Affecting ◽  
Composite Molding ◽  
Composites Processing ◽  
Stress And Deformation ◽  
Fiber Preforms

Resin-rich zones are a common phenomenon in liquid composite molding processes. These resin-rich zones cause unwanted residual stress and deformation, and part-to-part variation, and thus they need to be studied in the design of composite structures. An experimental study on the formation of resin-rich zones in angled composite parts is presented in this paper. Two open-channel mold sets were designed and fabricated. Fiber preforms were loaded into these molds and the gaps formed were visually inspected by a microscope. The influences of corner radius, fiber volume fraction, enclosed angle, and stacking sequence were investigated, and significant factors affecting gap thickness were identified by Design of Experiments (DOE). It can be concluded from the experimental results that: 1) Fiber volume fraction is the most significant factor affecting gap thickness. Gap thickness is inversely proportional to fiber volume fraction; 2) Gap thickness is inversely proportional to radius; 3) The gap thickness of unidirectional preforms is larger than that of the cross-ply preforms.

Enhanced Tensile and Wear Properties of CFRP Composites Manufactured Using Vacuum Infusion Process

2019 ◽  
Vol 969 ◽  
pp. 271-277
Author(s):  
Syam Kumar Chokka ◽  
Beera Satish Ben ◽  
K.V. Sai Srinadh
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Volume Fraction ◽  
Longitudinal Direction ◽  
Wear Behaviour ◽  
Wear Properties ◽  
Fiber Volume ◽  
Vacuum Infusion ◽  
Cfrp Composites ◽  
Vacuum Infusion Process

The properties of a composite are depending on the manufacturing process, fiber and its configuration, epoxy used etc. The present research deals with the tensile and wear behaviour of the composites manufactured using Hand Layup (HL) and Vacuum Infusion Process (VIP) with structural and non-structural epoxy combination. 4-layerd (all the layers are oriented in the longitudinal direction) unidirectional CFRP was manufactured using VIP and those results were compared with the HL made samples. The addition of structural epoxy in the resin mixer have shown a significant effect on its fiber volume fraction, tensile and erosion properties. The effect of vacuum pressure in mould cavity on the tensile strength of the CFRP composite was also studied. The morphologies of the CFRP composites made with VIP and HL were studied with the help of the scanning electron microscopy (SEM). The CFRP composites manufactured through VIP have shown a greater tensile strength but it was poor in wear resistance. The addition of structural adhesive to the resin system enhanced the wear resistance. Hence it made the VIP a recommended process for composite manufacturing where both tensile and wear properties are required.

scholarly journals Flexural Strength of Banana Fibre Reinforced Epoxy Composites Produced through Vacuum Infusion and Hand Lay-Up Techniques - A Comparative Study

2017 ◽  
Vol 2 (2) ◽  
pp. 31-36 ◽  
Author(s):  
Mohamed Rahman ◽  
Abdul Aziz Jasani ◽  
Mohd Azizuddin Ibrahim
Keyword(s):  
Flexural Strength ◽  
Fiber Length ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Water Solution ◽  
Fiber Volume ◽  
Banana Fiber ◽  
Vacuum Infusion ◽  
Banana Fibre ◽  
Vacuum Infusion Process

Natural fiber such as kenaf, sisal, pineapple leaf and banana are growing popular nowadays due to its favor over traditional glass fiber and inorganic material. It is a renewable resources and abundantly available in the market. The composites made of natural fiber are economical, lightweight and environmental friendly. This study works on producing a composite based on the Banana fiber reinforced epoxy resin by using the method of Vacuum Infusion and Hand Lay-up. Banana fiber will be treated with Sodium Hydroxide (NaOH) and water solution for 1 hour and then dried in the oven for 24 hours at 100°C. The composite will be produce based on different fiber volume fraction of 20% and 40% as well as different fiber length of 127mm, and 63mm. In Vacuum Infusion process, a mold made of aluminium have been manufactured according to the size of specimens of 127mm x 12.7mm x 3.2mm in dimension will be used in the preparation of specimens. The specimens of different volume fraction and fiber length produced by vacuum infusion and hand lay-up method will be mechanically tested through flexural test. The highest flexural strength is the specimen made by vacuum infusion process with 40% volume fraction and 63mm fiber length, which is 136.27MPa while for the hand lay-up process, the highest flexural strength is 80.71 with 40% volume fraction and 63mm fiber length.

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.

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

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.

Sign in / Sign up

Export Citation Format

Share Document