A study of detection of internal defects in CFRP using different modes of planar laser

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1357-1364
Author(s):  
Qiang Wang ◽  
Qiuping Hu ◽  
Jinxing Qiu ◽  
Cuixiang Pei ◽  
Hongbin Zhou ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Sine Wave ◽  
Wave Mode ◽  
Carbon Fiber Composites ◽  
Internal Defects ◽  
Laser Method ◽  
Reinforced Polymer ◽  
Wave Heating ◽  
Planar Laser ◽  
Heating Mode

The detection for internal defects of the practical aviation carbon fiber reinforced polymer (CFRP) using different modes of laser was discussed in this paper. The results show that the effect of the laser with long pulsed wave heating mode is the best, and then sawtooth wave mode is followed by sine wave mode. Besides, the valid image processing method plays a significant role in improving the effect of differential laser infrared thermography. Compared with the detection results of thermal lamp thermography, the effect of differential laser thermography is better. There are two main advantages of using a planar laser to heat the aviation carbon fiber composites: (1) the detection speed is so fast, which only takes a few seconds to complete the whole detection process; (2) laser method is more flexible than thermal lamp thermography because of the range detected can be adjusted according to the aim of experiments.

scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 203
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Impact Test ◽  
Carbon Fiber Composites ◽  
Internal Defects ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Fibers Orientation ◽  
Lock In ◽  
The Impact

With the increasing use of carbon fiber reinforced plastics in various fields, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For the non-contact evaluation of internal defects, the lock-in infrared thermography was proposed to investigate the defects in the composites subjected to the compression after impact test (CAI). The drop-weight impact test was conducted to study the impact behavior of the composites according to fibers orientation for composite fabricated using unidirectional (UD) carbon fiber prepregs. Using CAI tests, the residual compressive strengths were determined, and the damage modes were detected using a thermal camera. The results of the drop weight impact tests showed that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. The specimens with 0°/90° and +45°/−45° fibers orientation exhibited more than 90% of the impact energy absorption and good impact resistance. Furthermore, the specimens that underwent the impact tests were subjected to compressive test simultaneously with the lock-in thermography defects detection. The results showed that internal delamination, fibers splitting, and broken fibers occurred. The temperature differences in the residual compression tests were not significant.

scholarly journals Analysis of Impact Characteristics and Detection of Internal Defects for Unidirectional Carbon Composites with Respect to Fiber Orientation

2020 ◽  
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
and Hong-gun Kim
Keyword(s):  
Carbon Fiber ◽  
Carbon Fiber Composites ◽  
Compression Tests ◽  
Internal Defects ◽  
Finite Elements Analysis ◽  
Impact Tests ◽  
Drop Weight ◽  
Weight Impact ◽  
Lock In ◽  
The Impact

.With the increasing use of carbon fiber reinforced plastics in various area, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For non-contact evaluation of internal defects, we proposed lock-in infrared thermography to investigate orientation angles after a compression test. We also conducted a drop-weight impact test to study the behaviour of the composites after impact according the fibers orientation for composite fabricated using unidirectional carbon fiber prepregs. Using CAI tests, we determined the residual compressive strength and confirmed the damage modes using a thermal camera. The results of the drop weight impact tests show that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. In contrast, the specimens oriented in of 0°/90° and +45°/–45° directions transferred more than 90% of the impact energy back to the impactor because of the lamination of fibers in the orthogonal directions. Furthermore, the specimens that underwent complete damage in the impact tests were subjected to the lock-in method and showed internal delamination and cut fibers. With the finite elements analysis, the damage of each ply could be observed. Moreover, the temperature differences in the residual compression tests were not significant.

Recycled Carbon Fiber as Flame Retardant in Palm-Based Polyurethane Composite

2015 ◽  
Vol 1087 ◽  
pp. 251-256 ◽  
Author(s):  
Khairiah Haji Badri ◽  
Mariana Mohd Zaini ◽  
Ahmad Zhafreen Reza Ahmad Redfzi ◽  
Muhammad Syukri Ngah
Keyword(s):  
Carbon Fiber ◽  
Chemical Interaction ◽  
Fiber Composites ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Carbon Fiber Composites ◽  
Polyurethane Composite ◽  
Reinforced Polymer ◽  
Polyurethane Composites ◽  
Sem Analyses

The effect of recovered carbon fiber (rCF) to the burning property of polyurethane composites was investigated. The carbon fiber reinforced polymer (CFRP) in mat form was first glycolysed at 190-200 oC and characterized by FTIR, TGA, DSC and SEM analyses. The rCF was added at 0, 0.5, 1.0 and 1.5% (w/w). The polyurethane filled with recovered carbon fiber composites (PU-rCF) have also undergone burning test. The TGA analysis of PU-rCF indicated the percentage of weight loss decreased from 95.6% to 91.4% as rCF content increased. The DSC showed the glass transition temperature, Tg of PU-rCF increased with increasing addition of rCF from 56.7 to 63.0oC. The burning rate of the PU-rCF decreased from 6.1 mm∙s-1 to 2.8 mm∙s-1 with increasing rCF. The FTIR analysis confirmed that there was no chemical interaction between the rCF and PU. The addition of rCF to PU has improved the burning property of the composite.

scholarly journals Carbon Fiber Reinforced Polymer with Shredded Fibers: Quasi-Isotropic Material Properties and Antenna Performance

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Gerald Artner ◽  
Philipp K. Gentner ◽  
Johann Nicolics ◽  
Christoph F. Mecklenbräuker
Keyword(s):  
Carbon Fiber ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Carbon Fiber Composites ◽  
Fiber Reinforced ◽  
Antenna Performance ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

A carbon fiber reinforced polymer (CFRP) laminate, with the top layer consisting of shredded fibers, is proposed and manufactured. The shredded fibers are aligned randomly on the surface to achieve a more isotropic conductivity, as is desired in antenna applications. Moreover, fiber shreds can be recycled from carbon fiber composites. Conductivity, permittivity, and permeability are obtained with the Nicolson-Ross-Weir method from material samples measured inside rectangular waveguides in the frequency range of 4 to 6 GHz. The decrease in material anisotropy results in negligible influence on antennas. This is shown by measuring the proposed CFRP as ground plane material for both a narrowband wire monopole antenna for 5.9 GHz and an ultrawideband conical monopole antenna for 1–10 GHz. For comparison, all measurements are repeated with a twill-weave CFRP.

scholarly journals Alkali-Activated Mortars Modified by Epoxy-Carbon Fiber Composites Wastes

2021 ◽  
Vol 11 (13) ◽  
pp. 6110
Author(s):  
Andrea Saccani ◽  
Stefania Manzi ◽  
Grazia Totaro ◽  
Isabella Lancellotti
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
Carbon Fiber Composites ◽  
Low Carbon ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Alkali Activated

Short chopped fibers coated by epoxy resin of different length (5 to 10 mm length) were added at low volume content (about 4.6% on the composite) to alkali-activated fly ash or metakaolin mortars. These uncured scraps derive from the production of carbon fiber-reinforced polymer composites and they are not presently recycled, despite their outstanding mechanical properties. The workability, microstructure, porosity, and physical and mechanical properties (mainly flexural strength) of the derived materials were investigated. Superior flexural strength and increased toughness were obtained. An acid treatment of the scraps further improved the mechanical properties of the mortars by changing the chemical structure of the surface, thus increasing the interaction with the inorganic phase. These results foster the use of these wastes to improve the performance of low carbon footprint building materials such as alkali-activated composites in the building industry.

Restoring Initially Cracked Reinforced Concrete Beams utilizing Carbon Fiber Reinforced Polymer Strips

2019 ◽  
Vol 7 (1) ◽  
pp. 30-34
Author(s):  
A. Ajwad ◽  
U. Ilyas ◽  
N. Khadim ◽  
Abdullah ◽  
M.U. Rashid ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Loading Test ◽  
Control Beam ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced polymer (CFRP) strips are widely used all over the globe as a repair and strengthening material for concrete elements. This paper looks at comparison of numerous methods to rehabilitate concrete beams with the use of CFRP sheet strips. This research work consists of 4 under-reinforced, properly cured RCC beams under two point loading test. One beam was loaded till failure, which was considered the control beam for comparison. Other 3 beams were load till the appearance of initial crack, which normally occurred at third-quarters of failure load and then repaired with different ratios and design of CFRP sheet strips. Afterwards, the repaired beams were loaded again till failure and the results were compared with control beam. Deflections and ultimate load were noted for all concrete beams. It was found out the use of CFRP sheet strips did increase the maximum load bearing capacity of cracked beams, although their behavior was more brittle as compared with control beam.

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