Prediction of statistical life time for unidirectional CFRTP under water absorption

2021 ◽  
pp. 073168442110517
Author(s):  
Masayuki Nakada ◽  
Yasushi Miyano ◽  
Soshi Kageta ◽  
Hirofumi Nishida ◽  
Yutaka Hayashi ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Water Absorption ◽  
Life Time ◽  
Fiber Reinforced ◽  
Statistical Life ◽  
The Matrix ◽  
Dry Conditions ◽  
Carbon Fiber Reinforced ◽  
Term Creep

Carbon fiber reinforced plastics (CFRP) with the matrix of thermoplastic resin called as carbon fiber reinforced thermoplastics (CFRTPs) has been widely used in the industrial fields. Recently, a thermoplastic epoxy resin (TP-EP resin) has been developed as the matrix of CFRTP and carbon fiber reinforced TP-EP strands (CF/TP strands) molded by pultrusion method began to be used as tension rods for infrastructure under water absorption. On the other hand, an accelerated testing methodology (ATM) for predicting statistically long-term creep and fatigue strengths of CFRP was established by the authors. This study examines the prediction of statistical life time for these developed CF/TP strands at creep and fatigue tension loadings under the wet condition of water absorption with comparison to similar prediction under a dry condition by using our developed ATM. First, the static, creep, and fatigue tensile strengths of CF/TP strands were measured statistically at various constant temperatures under wet and dry conditions. The statistical long-term creep and fatigue tensile strengths for CF/TP strands under wet and dry conditions are predicted by substituting the measured data into the formulations of these strengths on our developed ATM. Finally, the influences of water absorption on the statistical long-term creep and fatigue strengths of CF/TP strands are cleared. In particular, the degradation of relaxation modulus of matrix TP-EP resin with increasing of elapsed time is accelerated with the water absorption, and the degradation of creep strength of CF/TP strand with increasing of elapsed time is also accelerated with the water absorption in the similar manner of matrix resin. On the other hand, the fatigue strength of CF/TP strand decreases scarcely with water absorption although this fatigue strength depends remarkably on the number of cycles to failure.

Prediction of statistical life time for unidirectional CFRTP under cyclic loading

2021 ◽  
pp. 073168442110055
Author(s):  
Masayuki Nakada ◽  
Yasushi Miyano ◽  
Soshi Kageta ◽  
Hirofumi Nishida ◽  
Yutaka Hayashi ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Epoxy Resin ◽  
Elevated Temperatures ◽  
Constant Strain Rate ◽  
Life Time ◽  
Fiber Reinforced ◽  
Statistical Life ◽  
The Matrix ◽  
Carbon Fiber Reinforced ◽  
Thermoset Epoxy

Recently, the Innovative Composite Center of Kanazawa Institute of Technology developed a thermoplastic epoxy resin (TP-EP). Resin-impregnated carbon fiber reinforced TP-EP (CF/TP) strands molded by pultrusion were developed by Komatsu Matere Co., Ltd., for use as tension rods. This study examines the prediction of the statistical life time for these developed CF/TP strands under cyclic tension loading with comparison to our earlier report of similar predictions for carbon fiber reinforced thermoset epoxy resin (CF/TS) strands having a thermoset epoxy resin (TS-EP) as a matrix. First, test methods for static and fatigue strengths at elevated temperatures were developed for CF/TP strands. Second, static and fatigue tensile strengths of CF/TP strands were measured statistically at various constant temperatures under a constant strain rate and frequency. The master curves of statistical fatigue tensile strengths for CF/TP strands were constructed by substituting the measured data into the formulations of these strengths based on the matrix resin viscoelasticity. The fatigue strength characteristics of CF/TP strands were discussed through comparison to those of CF/TS strands with thermosetting epoxy resin as the matrix.

Effects of high pressure on the crystallization of carbon fiber reinforced polyetheretherketone (CF/PEEK) laminate composites

1990 ◽  
Vol 48 (4) ◽  
pp. 876-877
Author(s):  
Hong-Ming Lin ◽  
C. H. Liu ◽  
R. F. Lee
Keyword(s):  
High Pressure ◽  
Carbon Fiber ◽  
Sample Surface ◽  
High Yield ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Peek Composite ◽  
Continuous Carbon Fiber ◽  
Carbon Fiber Reinforced

Polyetheretherketone (PEEK) is a crystallizable thermoplastic used as composite matrix materials in application which requires high yield stress, high toughness, long term high temperature service, and resistance to solvent and radiation. There have been several reports on the crystallization behavior of neat PEEK and of CF/PEEK composite. Other reports discussed the effects of crystallization on the mechanical properties of PEEK and CF/PEEK composites. However, these reports were all concerned with the crystallization or melting processes at or close to atmospheric pressure. Thus, the effects of high pressure on the crystallization of CF/PEEK will be examined in this study.The continuous carbon fiber reinforced PEEK (CF/PEEK) laminate composite with 68 wt.% of fibers was obtained from Imperial Chemical Industry (ICI). For the high pressure experiments, HIP was used to keep these samples under 1000, 1500 or 2000 atm. Then the samples were slowly cooled from 420 °C to 60 °C in the cooling rate about 1 - 2 degree per minute to induce high pressure crystallization. After the high pressure treatment, the samples were scanned in regular DSC to study the crystallinity and the melting temperature. Following the regular polishing, etching, and gold coating of the sample surface, the scanning electron microscope (SEM) was used to image the microstructure of the crystals. Also the samples about 25mmx5mmx3mm were prepared for the 3-point bending tests.

scholarly journals Multiscale Composites: Assessment of a Feasible Manufacturing Process

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
R. Volponi ◽  
P. Spena ◽  
F. De Nicola ◽  
L. Guadagno
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Manufacturing Process ◽  
Resin Transfer Molding ◽  
Fiber Reinforced ◽  
Transfer Molding ◽  
Macro Scale ◽  
Multiscale Composite ◽  
The Matrix ◽  
Carbon Fiber Reinforced

A very interesting field of research on advanced composite materials is the possibility to integrate new functionalities and specific improvements acting on the matrix of the composite by means of a nanocharged resin. In this way, the composite becomes a so-called “multiscale composite” in which the different phases change from nano to macro scale. For example, the incorporation of nanoscale conductive fillers with intrinsically high electrical conductivity could allow a tailoring of this property for the final material. The properties of carbon nanotubes (CNT) make them an effective candidate as fillers in polymer composite systems to obtain ultralight structural materials with advanced electrical and thermal characteristics. Nevertheless, several problems are related to the distribution in the matrix and to the processability of the systems filled with CNT. Existing liquid molding processes such as resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM) can be adapted to produce carbon fiber reinforced polymer (CFRP) impregnated with CNT nanofilled resins. Unfortunately, the loading of more than 0.3-0.5% of CNT can lead to high resin viscosities that are unacceptable for such kind of processes. In addition to the viscosity issues that are related to the high CNT content, a filtration effect of the nanofillers caused by the fibrous medium may also lead to inadequate final component quality. This work describes the development of an effective manufacturing process of a fiber-reinforced multiscale composite panel, with a tetra-functional epoxy matrix loaded with carbon nanotubes to increase its electrical properties and with GPOSS to increase its resistance to fire. A first approach has been attempted with a traditional liquid infusion process. As already anticipated, this technique has shown considerable difficulties related both to the low level of impregnation achieved, due to the high viscosity of the resin, and to the filtration effects of the dispersed nanocharges. To overcome these problems, an opportunely modified process based on a sort of film infusion has been proposed. This modification has given an acceptable result in terms of impregnation and morphological arrangement of CNTs in nanofilled CFRP. Finally, the developed infiltration technique has been tested for the manufacture of a carbon fiber-reinforced panel with a more complex shape.

scholarly journals Temperature dependence of statistical fatigue strengths for unidirectional carbon fiber reinforced plastics under tension loading

2019 ◽  
Vol 54 (14) ◽  
pp. 1797-1806 ◽  
Author(s):  
Masayuki Nakada ◽  
Yasushi Miyano
Keyword(s):  
Fatigue Strength ◽  
Carbon Fiber ◽  
Longitudinal Direction ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
The Matrix ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
Tension Loading

The formulation for time- and temperature-dependent statistical static and fatigue strengths for carbon fiber reinforced plastics laminates is newly proposed based on the physically serious role of resin viscoelasticity as the matrix of carbon fiber reinforced plastics. In this study, this formulation is applied to the tensile strength along the longitudinal direction of unidirectional carbon fiber reinforced plastics constituting the most important data for the reliable design of carbon fiber reinforced plastics structures which are exposed to elevated temperatures for a significant period of their operative life. The statistical distribution of the static and fatigue strengths under tension loading along the longitudinal direction of unidirectional carbon fiber reinforced plastics were measured at various temperatures by using resin-impregnated carbon fiber reinforced plastics strands as specimens. The master curves for the fatigue strength as well as the static strength of carbon fiber reinforced plastics strand were constructed based on the time–temperature superposition principle for the matrix resin viscoelasticity. The long-term fatigue strength of carbon fiber reinforced plastics strand can be predicted by using the master curve of fatigue strength.

scholarly journals Effect of fiber content and their hybridization on bending and torsional strength of hybrid epoxy composites reinforced with carbon and sugar palm fibers

Polimery ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 36-43 ◽  
Author(s):  
N. M. Z. Nik Baihaqi ◽  
A. Khalina ◽  
N. Mohd Nurazzi ◽  
H. A. Aisyah ◽  
S. M. Sapuan ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Torsion Test ◽  
Epoxy Composites ◽  
Fiber Reinforced ◽  
Fiber Loading ◽  
The Matrix ◽  
Carbon Fiber Reinforced Composites ◽  
Carbon Fiber Reinforced

This study aims to investigate the effect of fiber hybridization of sugar palm yarn fiber with carbon fiber reinforced epoxy composites. In this work, sugar palm yarn composites were reinforced with epoxy at varying fiber loads of 5, 10, 15, and 20 wt % using the hand lay-up process. The hybrid composites were fabricated from two types of fabric: sugar palm yarn of 250 tex and carbon fiber as the reinforcements, and epoxy resin as the matrix. The ratios of 85 : 15 and 80 : 20 were selected for the ratio between the matrix and reinforcement in the hybrid composite. The ratios of 50 : 50 and 60 : 40 were selected for the ratio between sugar palm yarn and carbon fiber. The mechanical properties of the composites were characterized according to the flexural test (ASTM D790) and torsion test (ASTM D5279). It was found that the increasing flexural and torsion properties of the non-hybrid composite at fiber loading of 15 wt % were 7.40% and 75.61%, respectively, compared to other fiber loading composites. For hybrid composites, the experimental results reveal that the highest flexural and torsion properties were achieved at the ratio of 85/15 reinforcement and 60/40 for the fiber ratio of hybrid sugar palm yarn/carbon fiber-reinforced composites. The results from this study suggest that the hybrid composite has a better performance regarding both flexural and torsion properties. The different ratio between matrix and reinforcement has a significant effect on the performance of sugar palm composites. It can be concluded that this type of composite can be utilized for beam, construction applications, and automotive components that demand high flexural strength and high torsional forces.

scholarly journals Durability of an Epoxy Resin and Its Carbon Fiber- Reinforced Polymer Composite upon Immersion in Water, Acidic, and Alkaline Solutions

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 614 ◽  
Author(s):  
Arya Uthaman ◽  
Guijun Xian ◽  
Sabu Thomas ◽  
Yunjia Wang ◽  
Qiang Zheng ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Epoxy Resin ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Alkaline Solutions ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Cfrp Composites ◽  
Carbon Fiber Reinforced

The usage of polymer composites in various engineering fields has increased. However, the long-term service performance of such materials under aggressive conditions is still poorly understood, which limits the development of safe and economically effective designs. In this study, the aging of an epoxy resin and its carbon fiber-reinforced polymer (CFRP) composites upon immersion in water, acidic, and alkaline solutions was evaluated at different temperatures. The service life of the CFRP composites under various conditions could be predicted by the Arrhenius theory. The thermal and mechanical analysis results indicated that the CFRP composites were more vulnerable to HCl owing to the higher moisture absorption and diffusion of HCl into their cracks. The scanning electron microscopy results showed that the polymer matrix was damaged and degraded. Therefore, to allow long-term application, CFRP composites must be protected from acidic environments.

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