Influence of Fiber’s Surface State on Mechanical Properties and Fiber-Matrix Interaction of CFRP

2013 ◽  
Vol 690-693 ◽  
pp. 323-328
Author(s):  
J. J. Sha ◽  
Y.X. Zhang ◽  
J. Li ◽  
J. X. Dai ◽  
Z. Q. Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Surface State ◽  
Elevated Temperatures ◽  
Fiber Surface ◽  
Flexural Test ◽  
Matrix Interaction ◽  
Fiber Matrix

In order to investigate the influence of carbon fiber’s surface state on the mechanical properties and the fiber-matrix interaction of CFRP, the change of surface state was achieved by thermal treatment of carbon fibers at elevated temperatures, and the surface state was characterized by XPS. The mechanical properties were measured from the flexural test. The CFRP reinforced with 600 °C treated fabrics containing the highest reactive functional groups, showed the highest flexural strength and modulus. But in the case of CFRP reinforced with 1500 °C treated fabrics containing the lowest reactive functional groups, exhibited the lowest flexural strength and modulus. Combining the mechanical properties with the microstructure analysis, the results indicated that the fiber-matrix interaction (strong or weak) depends on the relative percentage of reactive functional groups present on the carbon fiber surface.

Manufacturing and Mechanical Property Evaluations of CF/PLA Biocomposites

2014 ◽  
Vol 910 ◽  
pp. 153-156
Author(s):  
Ching Wen Lou ◽  
Jo Mei Liao ◽  
Zheng Lan Lin ◽  
Jia Horng Lin
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Impact Strength ◽  
Flexural Strength ◽  
Tensile Test ◽  
Carbon Fibers ◽  
Impact Test ◽  
Flexural Modulus ◽  
Flexural Test

This study uses carbon fibers (CF) to reinforce polylactic acid (PLA) matrices to form CF/PLA biocomposites. Tensile test, flexural test, and impact test are performed on biocomposites to evaluate their mechanical properties. The results of tests show that an increment of the CF content results in an increase in tensile strength, flexural strength, flexural modulus, and impact strength. The combination of 15 wt% CF provides the resulting biocomposites with a 72 % increase in tensile strength, a 322 % increase in flexural modulus, and a 96 % increase in impact strength.

scholarly journals Thermo-mechanical behavior of epoxy composite reinforced by carbon and Kevlar fiber

2018 ◽  
Vol 225 ◽  
pp. 01022
Author(s):  
Falak O. Abasi ◽  
Raghad U. Aabass
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Epoxy Composites ◽  
Fiber Reinforced ◽  
Fiber Loading ◽  
Kevlar Fiber ◽  
Carbon Fiber Reinforced ◽  
Short Carbon

Newer manufacturing techniques were invented and introduced during the last few decades; some of them were increasingly popular due to their enhanced advantages and ease of manufacturing over the conventional processes. Polymer composite material such as glass, carbon and Kevlar fiber reinforced composite are popular in high performance and light weight applications such as aerospace and automobile fields. This research has been done by reinforcing the matrix (epoxy) resin with two kinds of the reinforcement fibers. One weight fractions were used (20%) wt., Epoxy reinforced with chopped carbon fiber and second reinforcement was epoxy reinforced with hybrid reinforcements Kevlar fiber and improved one was the three laminates Kevlar fiber and chopped carbon fibers reinforced epoxy resin. After preparation of composite materials some of the mechanical properties have been studied. Four different fiber loading, i.e., 0 wt. %, 20wt. % CCF, 20wt. % SKF, AND 20wt. %CCF + 20wt. % SKF were taken for evaluating the above said properties. The thermal and mechanical properties, i.e., hardness load, impact strength, flexural strength (bending load), and thermal conductivity are determined to represent the behaviour of composite structures with that of fibers loading. The results show that with the increase in fiber loading the mechanical properties of carbon fiber reinforced epoxy composites increases as compared to short carbon fiber reinforced epoxy composites except in case of hardness, short carbon fiber reinforced composites shows better results. Similarly, flexural strength test, Impact test, and Brinell hardness test the results show the flexural strength, impact strength of the hybrid composites values were increased with existence of Kevlar fibers, while the hardness was decrease. But the reinforcement with carbon fibers increases the hardness and decreases other tests.

scholarly journals CARBON FIBRE ALIGNMENT FOR REINFORCED COMPOSITES USING EMBROIDERY TECHNOLOGY

2021 ◽  
Vol 2021 ◽  
pp. 102-108
Author(s):  
J. Domenech-Pastor ◽  
P. Diaz-Garcia ◽  
D. Garcia
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Carbon Fibre ◽  
Carbon Fibers ◽  
Vertical Direction ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Reinforced Composites ◽  
Good Opportunity ◽  
Fibre Reinforced Composites

Composites are materials formed by the combination of two or more components that acquire better properties than the ones obtained by each component on its own. Composites have been widely used in the industry due to its light weight and good mechanical properties. To improve these properties several layers of reinforced material (e.g., carbon fibre) are overlapped which produce an increase in the fibre consumption. In this sense Tailored Fibre Placement (TFP) embroidery can offer good opportunity to reduce the consumption of reinforced fibre while improving the mechanical properties due to the alignment of the fibres in the effort direction. This study analyzes the performance of carbon fibre reinforced composites with Polyester resin made with TFP embroidery technology against flexural strength efforts and without using plain woven fabrics to demonstrate that the use of reinforcement fabrics in composites can be optimized by a curved alignment of the fibers. Two different structures were embroidered with TFP technology, one simulating a woven fabric with straight unidirectional alignment of fibres in horizontal and vertical direction, and a second structure made with curvilinear alignment of carbon fibers. After the study of the flexural mechanical properties an improvement of 18% was obtained in maximum flexural strength.

Effect of CNT Grafting on Carbon Fibers on Impact Properties of CFRTP Laminate

2018 ◽  
Vol 774 ◽  
pp. 410-415 ◽  
Author(s):  
Kazuto Tanaka ◽  
Ken Uzumasa ◽  
Tsutao Katayama
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Impact Properties ◽  
Specific Strength ◽  
Out Of Plane ◽  
Reinforced Thermoplastics ◽  
The Impact

Carbon fiber reinforced thermoplastics (CFRTP) are expected to be used as a structural material for aircraft and automobiles not only for their mechanical properties such as high specific strength and high specific rigidity but also for their high recyclability and short molding time. Generally, in a composite material having a laminated structure, interlaminar delamination is often caused by an out-of-plane impact, so the interlayer property plays an important role in the mechanical properties. It has been reported that the fiber/matrix interfacial strength increases by grafting carbon nanotubes (CNT) on the carbon fiber surface. In this study, CNT grafted carbon fibers were used for reinforcement of CFRTP laminate for the improvement of impact properties of CFRTP laminates. The impact absorbed energy of the CFRTP laminate using CNT grafted carbon fibers as reinforcing fiber was higher than that using untreated CF.

scholarly journals Microstructure and mechanical properties of short-carbon-fiber/Ti3SiC2 composites

2020 ◽  
Vol 9 (6) ◽  
pp. 716-725
Author(s):  
Guangqi He ◽  
Rongxiu Guo ◽  
Meishuan Li ◽  
Yang Yang ◽  
Linshan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Vickers Hardness ◽  
Matrix Composites ◽  
Transition Layers ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Short Carbon

AbstractShort-carbon-fibers (Csf) reinforced Ti3SiC2 matrix composites (Csf/Ti3SiC2, the Csf content was 0 vol%, 2 vol%, 5 vol%, and 10 vol%) were fabricated by spark plasma sintering (SPS) using Ti3SiC2 powders and Csf as starting materials at 1300 °C. The effects of Csf addition on the phase compositions, microstructures, and mechanical properties (including hardness, flexural strength (σf), and KIC) of Csf/Ti3SiC2 composites were investigated. The Csf, with bi-layered transition layers, i.e., TiC and SiC layers, were homogeneously distributed in the as-prepared Csf/Ti3SiC2 composites. With the increase of Csf content, the KIC of Csf/Ti3SiC2 composites increased, but the σf decreased, and the Vickers hardness decreased initially and then increased steadily when the Csf content was higher than 2 vol%. These changed performances (hardness, σf, and KIC) could be attributed to the introduction of Csf and the formation of stronger interfacial phases.

Performance of ilmenite concrete at sustained elevated temperatures

1988 ◽  
Vol 15 (5) ◽  
pp. 776-783
Author(s):  
H. S. Wilson
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Key Words ◽  
Elevated Temperatures ◽  
Cement Ratio ◽  
Nondestructive Tests ◽  
High Temperature Mechanical Properties ◽  
Curing Period

Two similar mixes were made with cement contents of about 350 kg/m3 and a water–cement ratio of 0.50. The concrete specimens, moist cured for 7 days, were cured in air for 28 and 120 days, respectively, prior to heating. The exposure temperatures were 75, 150, 300, and 450 °C. The periods of exposure at each temperature were 2, 30, and 120 days.The compressive strengths, before heating, of the specimens cured for 35 and 120 days were 41.0 and 46.2 MPa, respectively, and the flexural strengths were 4.9 and 5.8 MPa. Compared with those strengths, the strengths of the specimens heated for 30 days or more increased at 75 °C but decreased at higher temperatures. The losses increased with increase in temperature, reaching about 30% at 450 °C.The flexural strength of the concrete cured in air for 28 days was more adversely affected than was the compressive strength. The flexural and compressive strengths of the concrete cured in air for 120 days were affected to about the same degree. The longer curing period had little effect on the relative losses in compressive strength, but the longer curing period reduced the loss in flexural strength. In most applications, the loss in strength could be compensated by proportioning the mix to overdesign for strength. Key words: high-density concrete, ilmenite, aggregates, high temperature, mechanical properties, nondestructive tests.

scholarly journals Mechanical Properties of Lightweight Concrete Using Recycled Cement-Sand Brick as Coarse Aggregates Replacement

2018 ◽  
Vol 34 ◽  
pp. 01029
Author(s):  
Ilya Joohari ◽  
Nor Farhani Ishak ◽  
Norliyati Mohd Amin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Mechanical Testing ◽  
Lightweight Concrete ◽  
Control Sample ◽  
Density Measurement ◽  
Flexural Test ◽  
Coarse Aggregates ◽  
Optimum Proportion ◽  
Natural Aggregates

This paper presents the result of replacing natural course aggregate with recycled cement-sand brick (CSB) towards the mechanical properties of concrete. Natural aggregates were used in this study as a control sample to compare with recycled coarse aggregates. This study was also carried to determine the optimum proportion of coarse aggregates replacement to produce lightweight concrete. Besides, this study was conducted to observe the crack and its behaviour development during the mechanical testing. Through this study, four types of concrete mixed were prepared, which were the control sample, 25%, 50% and 75% replacement of CSB. The test conducted to determine the effectiveness of recycled CSB as coarse aggregates replacement in this study were slump test, density measurement, compression test, and flexural test and. The strength of concrete was tested at 7 days and 28 days of curing. From the results obtained, the optimum proportion which produced the highest strength is 25% replacement of recycled CSB. The compressive and flexural strength has decreased by 10%-12% and 4%-34% respectively compared to the control sample. The presence of recycled coarse aggregates in sample has decreased the density of concrete by 0.8%-3% compared to the control sample.

Effect of Heat Treatment on Mechanical Properties of Laminated Carbon Fiber Reinforced Polymeric Composites

2016 ◽  
Author(s):  
A. B. M. I. Islam ◽  
Ajit D. Kelkar ◽  
Lifeng Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Surface ◽  
Fiber Reinforced ◽  
Carbon Fabric ◽  
Carbon Fiber Reinforced ◽  
Fiber Deposition ◽  
Pan Fibers

In recent years use of electrospun nanofibers and nanoparticles to improve the interlaminar properties have increased significantly. In most of the cases the additional interlaminar phase of nanofibers is required to go through various thermal and/or chemical processes. There has been emphasis to optimize the interlaminar nanofiber layers to achieve the optimum desired mechanical properties such as interlaminar strength. One common practice is to disperse nanofibers into the resin and then use the nanofiber enhanced resin to fabricate the laminated composites. However, proper dispersion and fiber filtering out are some of the problems that exist in fabrication using the nanofiber mixed resin approach. To alleviate this problem, an innovative approach of growing PAN (polyacrylnitrile) nano fibers directly on carbon fabric by electrospinning seems to solve the dispersion and fiber filtering problem. However, as PAN fibers require stabilization and carbonization, it is obvious that carbon fabric with PAN fiber deposition will have to undergo stabilization and carbonization process. The effect of stabilization and carbonization heat treatment on the mechanical properties of carbon fiber fabric is not yet fully understood. This paper presents the effects of heat treatment on carbon fabric used for fabricating laminated carbon fiber reinforced composite with epoxy resin. The heat treatment was performed at 280°C in air for six hours, and 1200°C for one hour in nitrogen which are similar to stabilization and carbonization of pure PAN fibers. The effects, due to heat treatment, were mainly characterized in terms of mechanical properties by performing tensile tests and shear tests. Fiber surface topography was observed by SEM to analyze physical changes. Chemical changes, corresponding to the existing groups with carbon fibers, were examined through FTIR. The results obtained are compared with a set of control laminated composite specimens, which were fabricated using heat vacuum assisted resin transfer molding (HVARTM) process and cured at 149°C. The two sets of composite were infused with resin in a single vacuum bag to ensure that both sets of specimens have identical resin infusion and cure cycle. Laminates used for making control specimens were fabricated using carbon fabric which did not undergo any heat treatment. A change in laminate thickness for heat treated carbon fabric was observed indicating a possible bulk up of the carbon fibers due to loss of sizing compounds, which also resulted into significant change in tensile properties.

scholarly journals Investigation on microstructure and mechanical properties of short-carbon-fiber/Ti3SiC2 composites

2020 ◽  
Author(s):  
Guangqi He ◽  
Rongxiu Guo ◽  
Meishuan Li ◽  
Yang Yang ◽  
Linshan Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Matrix Composites ◽  
Transition Layers ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Short Carbon

Abstract In this paper, short-carbon-fibers (Csf) reinforced Ti3SiC2 matrix composites (Csf/Ti3SiC2, the Csf content was 0, 2, 5 and 10 vol.%) were fabricated by spark-plasma-sintering (SPS) using Ti3SiC2 powders and Csf as starting materials at 1300 oC. The effects of Csf addition on the phase compositions, microstructures and mechanical properties (including hardness, flexural strength and fracture toughness) of Csf/Ti3SiC2 composites were investigated. The Csf, with a bi-layered transition layers, i.e. TiC and SiC layer, were homogeneously distributed in the as-prepared Csf/Ti3SiC2 composites. With the increase of Csf content, the fracture toughness of Csf/Ti3SiC2 composites increased, but the flexural strength decreased, while the Vickers hardness decreased initially then increased steadily when the Csf content was higher than 2 vol.%. These changed performances could be attributed to the introduction of Csf and the formation of much stronger interfacial phases.

scholarly journals Mechanical Properties of SiO2-Coated Carbon Fiber-Reinforced Mortar Composites with Different Fiber Lengths and Fiber Volume Fractions

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Gwang-Hee Heo ◽  
Jong-Gun Park ◽  
Ki-Chang Song ◽  
Jong-Ho Park ◽  
Hyung-Min Jun
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Carbon Fibers ◽  
Cement Matrix ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Volume Fractions ◽  
Carbon Fiber Reinforced ◽  
Coated Carbon

In the present study, SiO2 particles were coated on the surface of carbon fibers by means of chemical reaction of silane coupling agent (glycidoxypropyl trimethoxysilane, GPTMS) and colloidal SiO2 sol to improve the interfacial bonding force between fibers and matrix in cement matrix. The surface of the modified carbon fibers was confirmed through a scanning electron microscope (SEM). The mechanical properties of SiO2-coated carbon fiber mortar and uncoated carbon fiber mortar with different fiber lengths (6 mm and 12 mm) and fiber volume fractions (0.5%, 1.0%, 1.5%, and 2.0%) were compared and analyzed. The experimental results show that the flow values of the carbon fiber mortar were greatly disadvantageous in terms of fluidity due to the nonhydrophilicity of fibers and fiber balls, and the unit weight decreased significantly as the fiber volume fractions increased. However, the air content increased more or less. In addition, regardless of whether the fibers were coated, the compressive strength of carbon fiber-reinforced mortar (CFRM) composite specimens tended to gradually decrease as the fiber volume fractions increased. On the other hand, in case of the SiO2-coated CFRM composite specimens, the flexural strength was significantly increased compared to uncoated CFRM composite specimens and plain mortar specimens, and the highest flexural strength was obtained at 12 mm and 1.5%, particularly. It can be seen that the new carbon fiber surface modification method employed in this study was very effective in enhancing the flexural strength as cement-reinforcing materials.

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