Crash Test of Carbon Composite

2016 ◽  
Vol 821 ◽  
pp. 385-391
Author(s):  
Michal Petrů ◽  
Martina Syrovátková ◽  
Martina Novotná

Composite structures are now increasingly used for their properties in all areas of industrial production where high specific strength is demanded. They gradually replace metal parts and components not only because they are lighter, but above all for their comparable and in many ways even better mechanical properties. Knowledge of behavior of simple synergies between the fibres and the matrix allows the prediction of behavior of complex components and their application in practice. The subject of this article is a description of an experiment and numerical model, that compares the mechanical properties of carbon fiber composite with the values obtained using analytical models. Carbon composite samples were studied in laboratory conditions through Barrier test (ie. Crash test).

2019 ◽  
Vol 3 (2) ◽  
pp. 179-188
Author(s):  
Suhas Sridhar ◽  
Rohan Patil ◽  
Aaquib Ashfaq ◽  
Harsha Vardhan ◽  
Anil Kumar

Nowadays the position of natural fibers in the world fiber is stable, growing in the area of their application, not only in textiles but also in more eco-friendly composites. This work is focused on study of the effect of  SiC as filler material on the banana peduncle/Carbon fibers reinforced hybrid composites. Four different laminates are fabricated by varying the matrix composition (BP, BP+SiC, carbon+BP, Carbon+BP+SiC ). The alkaline treatment with 6% NaoH of the BP fibers improves the specific strength and binding properties. The filler added composites laminates shows higher mechanical properties. From the results, it is seen that mechanical properties like Tensile, Flexural, ILSS, Impact and hardness are improved by 89, 75, 99, 68 and 64% by the addition of the SiC to the banana peduncle/Carbon fiber composite laminate.


Author(s):  
Hamid Nayeb Hashemi ◽  
Gongdai Liu ◽  
Ashkan Vaziri ◽  
Masoud Olia ◽  
Ranajay Ghosh

In this paper, we mimic the venous morphology of a typical plant leaf into a fiber composite structure where the veins are replaced by stiff fibers and the rest of the leaf is idealized as an elastic perfectly plastic polymeric matrix. The variegated venations found in nature are idealized into three principal fibers — the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element (FE) based computational investigation of the mechanical properties such as Young’s moduli, Poisson’s ratio and yield stress under uniaxial loading of the resultant composite structures and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find significant effect of fiber inclination on the overall mechanical properties of the composites with higher fiber angles transitioning the composite increasingly into a matrix-dominated response. We also find that in general, composites with only secondary fibers are stiffer with closed cell architecture of the secondary fibers. The closed cell architecture also arrested the yield stress decrease and Poisson’s ratio increase at higher fiber angles thereby mitigating the transition into the matrix dominated mode. The addition of tertiary fibers also had a pronounced effect in arresting this transition into the matrix dominated mode. However, it was found that indiscriminate addition of tertiary fibers may not provide desired additional stiffness for fixed volume fraction of constituents. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.


Author(s):  
M.O. Kaptakov

In this work, the mechanical properties of composite samples prepared using a conventional and nanomodified matrix were studied. The thickness of the monolayers in the samples was 0,2 μm. It was found in experiments, that the addition of fullerene soot as a nanomodifierled to an increase in the mechanical properties of the samples along the direction of reinforcement. At the same time, an improvement in the quality of the contact of the matrix with the fibers in the samples with the nanomodifier was observed: on the fracture surface, the nanomodified matrix envelops the fibers, while the usual matrix completely exfoliates. The obtained effects of changing the strength of composites can be associated, among other things, with a change in the level of residual stresses arising in composites during nanomodification. Analytical and numerical modeling methods are used to explain these effects.


2015 ◽  
Author(s):  
Risa Yoshizaki ◽  
Kim Tae Sung ◽  
Atsushi Hosoi ◽  
Hiroyuki Kawada

Carbon nanotubes (CNTs) have very high specific strength and stiffness. The excellent properties make it possible to enhance the mechanical properties of polymer matrix composites. However, it is difficult to use CNTs as the reinforcement of long fibers because of the limitation of CNT growth. In recent years, a method to spin yarns from CNT forests has developed. We have succeeded in manufacturing the unidirectional composites reinforced with the densified untwisted CNT yarns. The untwisted CNT yarns have been manufactured by drawing CNTs through a die from vertically aligned CNT arrays. In this study, the densified untwisted CNT yarns with a polymer treatment were fabricated. The tensile strength and the elastic modulus of the yarns were improved significantly by the treatment, and they were 1.9 GPa and 140 GPa, respectively. Moreover, the polymer treatment prevented the CNT yarns from swelling due to impregnation of the matrix resin. Finally, the high strength CNT yarn composites which have higher volume fraction than a conventional method were successfully fabricated.


Author(s):  
Fabrizio Quadrini ◽  
Giovanni Matteo Tedde ◽  
Loredana Santo

Shape memory composites combine structural properties of continuous-fiber polymer-matrix composites with functional behavior of shape memory polymers. In this study, the production of shape memory composite structures for aerospace applications is described. Small-scale grabbing systems were prototyped as they could be used for space cleaning operations. Composite hands were manufactured by using two carbon fiber composite layers with a shape memory polymer interlayer. They were produced in the closed-hand configuration and subsequently opened in the memorizing step. Due to heating, composites tended to recover the initial closed configuration, allowing to grab small objects. Two different shapes (cylindrical and cubic) were considered for composite hands. In the first case, the shape memory behavior was given to the entire structure whereas, in the second case, shape memory properties were provided only to folding zones. As a result, a good shape recovery was observed in both cases but part weight was already not negligible also in these small-scale systems.


2021 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Michal Švantner ◽  
Lukáš Muzika ◽  
Alexey Moskovchenko ◽  
Celeste M. C. Pereira ◽  
Shumit Das

Thermographic flash-pulse inspection is one of popular methods of non-destructive testing (NDT) of materials. Despite the automation of the NDT methods, most of them are based on visual inspections and results of these inspections are influenced by the skills of operators. The repeatability and reproducibility (R&R) of these inspections are therefore more important compared to exact gauge-type methods. This study was focused on the statistical evaluation of flash pulse inspection. Space hardware representative carbon-fiber composite samples with 50 artificial defects were used as reference samples, which were independently inspected by three operators in two independent runs. A Gage R&R study was performed based on contrast to noise ratio defects identification. It was determined that at certain conditions, a total R&R variability 29% can be achieved, which can be assumed as acceptable for this application.


2021 ◽  
pp. 2188-2196
Author(s):  
Tagreed M. Al-Saadi ◽  
Anaam W. Watan ◽  
Hanaa G. Attiya

This study was achieved to satisfy two goals, the first of which is to treat an environmental problem represented by the disposal of date seeds, and the second is the use of these wastes to improve some mechanical and thermal properties of poly methyl methacrylate PMMA through strengthening different proportions of the powder of date seeds. Particles of date seeds were used as a natural strengthening material for PMMA polymer, by mixing the matrix material (resin) with the hardener while still stirring continuously for a period of 10 min. After that, the samples of the reinforced material were prepared by adding the powder of date seeds, which is the reinforcing substance, with different percentages of weight fraction (0, 0.5, 1, 2, 3, 5 wt. %) and a grain size of <75 µm, while continuing to stir (10 min) for a second time. The composite samples were prepared by the Hand-Lay-up method and cut according to the standard ASTM. Thermal conductivity and some mechanical properties, such as impact strength, tensile strength, compressive strength, flexural strength, and hardness, were studied. An improvement was found in all properties at the reinforcement rate of 1-2 wt. %.


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