Mean values of the mechanical properties of carbon fibers from test results on carbon-fiber-reinforced plastics

1976 ◽  
Vol 8 (8) ◽  
pp. 909-914
Author(s):  
G. M. Gunyaev ◽  
L. P. Kobets ◽  
G. G. Zaitsev
Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1866
Author(s):  
Chun Pei ◽  
Peiheng Guo ◽  
Ji-Hua Zhu

Preserving the integrity of carbon fibers when recycling carbon-fiber-reinforced plastics (CFRPs) has been unfeasible due to the harsh reaction conditions required to remove epoxy resin matrixes, which adversely affect the properties of carbon fibers. We establish a practicable and environmentally friendly reclamation strategy for carbon fibers. Carbon fibers are recycled from waste CFRPs by an electrochemical catalytic reaction with the assistance of phosphotungstic acid (PA), which promotes the depolymerization of diglycidyl ether of bisphenol A/ethylenediamine (DGEBA/EDA) epoxy resin. The removal rate, mechanical strength, and microstructure of the recycled carbon fibers are analyzed to explore the mechanism of the electrochemical treatment. The influence of three factors—current density, PA concentration, and reaction time—are studied via an orthogonal method. Range analysis and variance analysis are conducted to investigate the significance of the factors. The optimal conditions are determined accordingly. The underlying CFRP degradation mechanism is also investigated.


2019 ◽  
Vol 3 (3) ◽  
pp. 85 ◽  
Author(s):  
El-Ghaoui ◽  
Chatelain ◽  
Ouellet-Plamondon ◽  
Mathieu

Carbon fiber reinforced plastics (CFRP) are appreciated for their high mechanical properties and lightness. Due to their heterogeneous nature, CFRP machining remains delicate. Damages are caused on the material and early tool wear occurs. The present study aims to evaluate the effects of fillers on CFRP machinability and mechanical behavior. CFRP laminates were fabricated by the vacuum assisted resin transfer molding (VARTM) process, using a modified epoxy resin. Three fillers (organoclay, hydrocarbon wax, and wetting agent) were mixed with the resin prior to the laminate infusion. Milling tests were performed with polycrystalline diamond (PCD) tools, equipped with thermocouples on their teeth. Machinability was then studied through the cutting temperatures and forces. Tensile, flexural, and short-beam tests were carried out on all samples to investigate the effects of fillers on mechanical properties. Fillers, especially wax, allowed us to observe an improvement in machinability. The best improvement was observed with 1% wax and 2% organoclay, which allowed a significant decrease in the cutting forces and the temperatures, and no deteriorations were seen on mechanical properties. These results demonstrate that upgrades to CFRP machining through the addition of nanoclays and wax is a path to explore.


2021 ◽  
Vol 7 (4) ◽  
pp. 81
Author(s):  
Patrick Scholle ◽  
Sören Rüther ◽  
Michael Sinapius

The electrical conductivity of carbon fibers can be used to enable the design of intrinsically smart carbon fiber reinforced plastics (CFRPs). Resistance and impedance measurements of the structural material itself can then be used to measure physical stimuli such as strain or damage without requiring a dedicated sensor to be installed. Measuring the resistance with high precision requires good electrical contact between the measurement equipment and the conductive carbon fibers. In the literature, many different combinations of surface contacting material and surface preparation procedures are used, but only seldomly compared to one another. This article aims to compare frequently used electrical contact methods by analyzing their contact resistance to a pultruded CFRP rod. Furthermore, this study explores the change of contact resistance with increasing mechanical strain. The results show that contact resistance is highly dependent on both the material used for contacting the fibers as well as the surface preparation technique. From the combinations analyzed in this article, the electrodeposition in combination with a surface treatment using concentrated sulphuric acid shows the most promising results.


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