scholarly journals Characterization of the Epoxy Resin and Carbon Fiber Reinforced Plastic Stress-Strain State by Modified Carbon Nanotubes

2018 ◽  
Vol 20 (2) ◽  
pp. 137
Author(s):  
A. Yermakhanova ◽  
M. Ismailov
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Plastic Strain ◽  
Epoxy Resin ◽  
Compression Strength ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

The epoxy resin in the form of Etal Inject-T compound, Sigratex KDK carbon fabric, Taunit-M carbon nanotubes conditionally named as CNT-1, as well as functionalized (modified) variety of them by grafting to the surface of new chemical groups: carboxylated ‒ CNT-2, carboxyl-hydroxylated ‒ CNT-3, amidated ‒ CNT-4 were used in the work. The experiments were performed on the compression strength and bending strength of the samples. The injection of CNT-1 into epoxy resin or carbon fiber reinforced plastic did not produce the hardening. The injection of 0.05% of CNT-2 into the epoxy resin had the following effect: there is no influence in the area of quasielastic strains, the hardening was up to 25% in the areas of plastic and elastic-plastic strain. The injection of 0.15% of functionalized carbon nanotubes into the carbon fiber reinforced plastic produced the hardening for compression with CNT-2 ‒ 6%, CNT-3 ‒ 12%, CNT-4 – 17%, for bending – CNT-2 – 44%, CNT-3 – 59%, CNT-4 – 132%. It is established that with an increase in the strain rate of epoxy resin from 1 to 5 mm/min the areas of plastic and elastic-plastic strain gradually are reduced, there is only quasielastic strain with brittle fracture at 20 mm/ min, this value can be accepted as its strength characteristic. With an increase in the strain rate of carbon fiber reinforced plastic from 1 to 20 mm/min the compression strength gradually increases from 398 MPa to 425 MPa, and then stabilizes.

Relationship Between Functionalized Multi-Walled Carbon Nanotubes and Damping Properties of Multi-Walled Carbon Nanotubes/Carbon Fiber-Reinforced Plastic Composites for Shaft

2020 ◽  
Vol 20 (11) ◽  
pp. 6862-6870
Author(s):  
Mi-Kyoung Hong ◽  
Woong-Ki Choi ◽  
Jong-Hyun Park ◽  
Yun-Su Kuk ◽  
Byoung-Suhk Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Plastic Composites ◽  
Reinforced Plastic ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Fiber Reinforced ◽  
Walled Carbon Nanotubes

The mechanical properties and damping behavior of carbon fiber-reinforced plastic composites with functionalized multi-walled carbon nanotubes were examined. The functionalized multi-walled carbon nanotubes were blended with epoxy resins to prepare multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites. The dispersion properties of functionalized multi-walled carbon nanotubes in epoxy resins were examined using surface free energy. The mechanical properties of functionalized multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites were measured by interlaminar shear strength and torsion strength. The functionalized multi-walled carbon nanotubes/carbon fiber-reinforced plastic composites had superior mechanical properties due to the increase in dispersion properties of functionalized multi-walled carbon nanotubes in epoxy resins. However, the tan delta values of damping behavior, analyzed by dynamic mechanical analysis, varied with the type of functional groups of functionalized multi-walled carbon nanotubes. The composites obtained from functionalized multi-walled carbon nanotubes obtained through spermidine amidation reaction and carbon fiber-reinforced plastic showed excellent tan delta values due to the flexible segments in side chains.

scholarly journals Stressing State Analysis of Reinforced Concrete Beam Strengthened by CFRP Sheet with Anchoring Device

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 576
Author(s):  
Liang Luo ◽  
Jie Lai ◽  
Jun Shi ◽  
Guorui Sun ◽  
Jie Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Strain Distribution ◽  
Carbon Fiber Reinforced Plastic ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Strain Distribution Pattern ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Cfrp Sheet ◽  
Carbon Fiber Reinforced

This paper investigates the working performance of reinforcement concrete (RC) beams strengthened by Carbon-Fiber-Reinforced Plastic (CFRP) with different anchoring under bending moment, based on the structural stressing state theory. The measured strain values of concrete and Carbon-Fiber-Reinforced Plastic (CFRP) sheet are modeled as generalized strain energy density (GSED), to characterize the RC beams’ stressing state. Then the Mann–Kendall (M–K) criterion is applied to distinguish the characteristic loads of structural stressing state from the curve, updating the definition of structural failure load. In addition, for tested specimens with middle anchorage and end anchorage, the torsion applied on the anchoring device and the deformation width of anchoring device are respectively set parameters to analyze their effects on the reinforcement performance of CFRP sheet through comparing the strain distribution pattern of CFRP. Finally, in order to further explore the strain distribution of the cross-section and analyze the stressing-state characteristics of the RC beam, the numerical shape function (NSF) method is proposed to reasonably expand the limited strain data. The research results provide a new angle of view to conduct structural analysis and a reference to the improvement of reinforcement effect of CFRP.

Study on the mechanism of inhomogeneous microdamage in short-pulse laser processing of carbon fiber reinforced plastic

2021 ◽  
pp. 073168442098359
Author(s):  
Luyao Xu ◽  
Jiuru Lu ◽  
Kangmei Li ◽  
Jun Hu
Keyword(s):  
Carbon Fiber ◽  
Pulse Energy ◽  
Short Pulse ◽  
Heterogeneous Material ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Processing Efficiency ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

In this article, a micro-heterogeneous material simulation model with carbon fiber and resin phase about laser ablation on carbon fiber reinforced plastic (CFRP) is established by Ansys. The ablation process of CFRP by nanosecond ultraviolet laser is simulated, and the mechanism of pulse energy and spot spacing on the heat-affected zone (HAZ) is studied, then the process parameters are optimized with the goal of HAZ size and processing efficiency, and finally the validity of the model is verified by experiments. It is found that the residual gradient and the width of the radial HAZ increase with the increase of the spot spacing, and the width of the axial HAZ decreases slightly with the increase of the spot spacing, which indicates the existence of the optimal spot spacing. Second, the ablation depth increases with the increase of the pulse energy, and the carbon fiber retains a relatively complete degree of exposure when the pulse energy is low, which has a certain guiding significance for the cleaning and bonding of CFRP.

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