scholarly journals Round Robin Tests to Determine Fiber Content of Carbon Fiber-Reinforced Thermoplastic Composites by Combustion and Thermogravimetry

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Masahiro Funabashi ◽  
Fumi Ninomiya ◽  
Akihiro Oishi ◽  
Wataru Mizuno ◽  
Kimitaka Tahira ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Combustion Method ◽  
Polyamide 6 ◽  
Round Robin ◽  
Fiber Content ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Research Institutes ◽  
Carbon Fiber Reinforced

To propose methods to determine the fiber content of carbon fiber-reinforced plastics (CFRP) for the International Organization for Standardization, the fiber contents of CFRP with polyamide-6 were measured using a combustion method based on ISO 14127 and a thermogravimetry method based on the modified ISO 9924-3 under a round robin test managed by the Polymer Subcommittee of the Industrial Technology Cooperative Promotion Committee in Japan. In the combustion method, the fiber contents of the CFRTP (~0.3 g) were determined by the mass of carbon fiber remaining after burning (ISO 14127). The fiber contents in weight of the CFRTP with 8, 9, or 10 plies were determined to be 55.720%, 61.088%, or 65.326%, respectively, by 17 research institutes. In the thermogravimetry method, the fiber contents of the CFRTP (~10 mg) were determined by the mass of carbon fiber remaining after heating it to 600°C in nitrogen gas using thermogravimetry apparatus (modified ISO 9924-3). The fiber contents of the CFRTP with 8, 9, or 10 plies were determined to be 56.908%, 61.579%, or 64.819%, respectively, by 8 research institutes. It was confirmed that thermogravimetry method was as accurate as the combustion method based on ISO 14127.

Fiber content measurement for carbon fiber–reinforced thermoplastic composites using carbonization-in-nitrogen method

2016 ◽  
Vol 31 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Qiushi Wang ◽  
Haibin Ning ◽  
Uday Vaidya ◽  
Selvum Pillay ◽  
Leigh-Ann Nolen
Keyword(s):  
Carbon Fiber ◽  
Fiber Content ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Specific Strength ◽  
Extended Application ◽  
Melt Impregnation ◽  
Carbon Fiber Reinforced ◽  
Hot Melt

Carbon fiber–reinforced thermoplastic composites are gaining increasing interest in various applications thanks to their combined properties of high specific stiffness, high specific strength, and superior toughness. Their mechanical properties are highly dependent on the carbon fiber content. In this study, the carbonization-in-nitrogen method (CIN) developed in previous work is used to measure the fiber content of carbon fiber thermoplastic composites. Three types of carbon fiber thermoplastic composite samples were prepared using hot-melt impregnation. The carbon fiber thermoplastic composite sample is carbonized in a nitrogen environment alongside a neat resin sample that is used for calibrating the resin carbonization percentage. A good agreement is achieved between the nominal carbon fiber content and the carbon fiber content measured using the CIN method. It is concluded that the CIN method is an accurate and efficient way to characterize the carbon fiber content for carbon fiber thermoplastic composites. This work completes the verification of the CIN method, which enables extended application to thermoplastic composites. Moreover, it has its unique merits on evaluating the carbon fiber content for high-temperature and solvent-resistant thermoplastic composites that would encounter challenges using other methods.

scholarly journals Development of intimate contact during processing of carbon fiber reinforced Polyamide-6 tapes

2017 ◽  
Vol 36 (8) ◽  
pp. 593-607 ◽  
Author(s):  
PM Schaefer ◽  
T Guglhoer ◽  
MGR Sause ◽  
K Drechsler
Keyword(s):  
Carbon Fiber ◽  
Polyamide 6 ◽  
Surface Topology ◽  
Analytical Models ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Intimate Contact ◽  
Low Viscosity ◽  
Full Contact ◽  
Carbon Fiber Reinforced

Contact development between the surfaces of two tapes is considered as a critical step in processing carbon fiber reinforced thermoplastic composites. In this study, the development of intimate contact between carbon fiber reinforced Polyamide-6 (PA-6) tapes is investigated experimentally using consolidation experiments and X-ray computed tomography for quantitative contact characterization. The experimental results indicate that the development of intimate contact occurs in the range of seconds even when temperatures are only slightly above the melting temperature and applied pressures is in the range of 1-4 kPa. Experimental data are compared with the results of the two analytical models proposed by Lee and Springer as well as Yang and Pitchumani. Both models overestimate the time needed to reach full contact for the PA-6 tape. In comparison to previously investigated PEEK materials, PA-6 has a relatively low viscosity and the tapes possess a resin-rich layer near the surface, which seems to influence the contact development process. Besides the assumptions made for viscosity, the sensitivity to input parameters describing the surface topology strongly influence the model results and the accuracy of predictions.

A micromechanical model of carbon fiber-reinforced plastic and steel hybrid laminate composites

2021 ◽  
pp. 002199832110075
Author(s):  
Minchang Sung ◽  
Hyunchul Ahn ◽  
Jinhyeok Jang ◽  
Dongil Kwon ◽  
Woong-Ryeol Yu
Keyword(s):  
Carbon Fiber ◽  
Compressive Stress ◽  
Fracture Strain ◽  
Matrix Material ◽  
Micromechanical Model ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
Hybrid Laminate

The fracture strain of carbon fiber-reinforced plastics (CFRPs) within CFRP/steel hybrid laminate composites is reportedly higher than that of CFRPs due to transverse compressive stress induced by the steel lamina. A micromechanical model was developed to explain this phenomenon and also to predict the mechanical behavior of CFRP/steel hybrid laminate composites. First, the shear lag theory was extended to calculate stress distributions on fibers and matrix material in a CFRP under multiaxial stress condition, considering three deformation states of matrix (elastic and plastic deformation and fracture) and the transverse compressive stress. Then, the deformation behavior of CFRP was predicted using average stress in the ineffective region and the Weibull distribution of carbon fibers. Finally, the mechanical properties of CFRP/steel hybrid laminate composites were predicted by considering the thermal residual stress generated during the manufacturing process. The micromechanical model revealed that increased transverse compressive stress decreases the ineffective lengths of partially broken fibers in the CFRP and results in increased fracture strain of the CFRP, demonstrating the validity of the current micromechanical model.

INCREASING SENSITIVITY OF EDDY CURRENT NON-DESTRUCTIVE TESTING OF DELAMINATION IN CARBON-FIBER REINFORCED PLASTICS

2021 ◽  
pp. 28-37
Author(s):  
P. N. Shkatov ◽  
G. A. Didin ◽  
A. A. Ermolaev
Keyword(s):  
Carbon Fiber ◽  
Eddy Current ◽  
Calculation Model ◽  
Fiber Reinforced ◽  
Destructive Testing ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced ◽  
The Difference

The paper is concerned with increasing sensitivity of eddy current nondestructive testing of most dangerous delamination in carbon-fiber reinforced plastics (CFRP). Increased sensitivity is achieved by separate registration and comparison of eddy current signals obtained from a set of stratifications of carbon fibers with the same orientation. The separation of eddy current signals is possible due to pronounced anisotropy of the electrical conductivity of the layers dominant in the direction of the fibers of the corresponding layer. Eddy-current signals are registered by eddy current probes with maximum sensitivity in a given angular direction. Prior to the scan eddy current signals of the probe are leveled on a defect-free area. The influence of the working gap on the difference between the eddy current signals of the probe is suppressed by normalizing it according to one of the signals. The analysis of the registered signals from delamination has been performed using an approximate calculation model. The reliability of the obtained results has been confirmed by comparison with experimental results and calculations using the finite element method.

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