scholarly journals Effect of moisture content of jute fabric and hybridization structure on the impact properties of jute and jute/glass hybrid composites

2016 ◽  
Vol 23 (4) ◽  
pp. 367-374
Author(s):  
Ying Yu ◽  
Yuqiu Yang ◽  
Kazuo Tanabe ◽  
Mitsuo Mastuda ◽  
Hiroyuki Hamada

AbstractA preliminary investigation on the impact properties and morphologies of unsaturated polyester reinforced with jute woven fabric recycled from used coffee bags with different moisture contents was conducted. The laminated structural effect of hybridization with glass woven fabric was also investigated. Jute/jute-laminated composites, and jute/glass/jute- and jute/jute/glass-laminated hybrid composites were fabricated by the hand lay-up method. Their impact properties were compared by drop-weight and the Izod impact tests. The acoustic emission (AE) technique was applied under a tensile load to detect micro-failure processes in the jute and jute/glass hybrid composites. The number of AE signals and the AE energy were monitored using two transducers with resonant frequencies of 140 kHz and 1 MHz. The results showed that the moisture content affected the mechanical properties of the composites. The strength and elongation at break of the jute yarn decreased with a decrease in moisture content. The AE characteristics and observations of the fracture surfaces revealed that the composites fabricated from jute fabric with low moisture content had a relatively higher initial fracture stress and higher resistance to micro-fractures. Moreover, the mechanical properties of the hybrid composites were significantly affected by the laminating structure.

In this research impact properties of the hybrid natural fiber composites made up of areca, kenaf fiber mats with a 10 wt. % of wood dust as the filler materials in six different stacking sequences are studied. The fibers are treated for 30 hours with 10 % of NaOH solution at room temperature to improve the adhesion properties of the fibers. The composites are made-up by hand lay-up procedure using unsaturated polyester resin combined with a catalyst of Methyl Ethyl Ketone Peroxide (MEKP) and accelerator of Cobalt. The fabricated composites are allowed to cure for 24 hours at room temperature by placing a dead weight which gives a compact pressure. After that the hybrid composites are cut as per ASTM D256 standard to carry out the impact test by Izod Charpy impact tester. Five samples in each stacking were tested for the average value. The impact energy absorbed by specimens with six different stacking sequences are compared. The morphological study of the fractured impact specimens are studied using Scanning Electron Microscope images


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4169
Author(s):  
Marcel Zambrzycki ◽  
Krystian Sokolowski ◽  
Maciej Gubernat ◽  
Aneta Fraczek-Szczypta

In this work, we present a comparative study of the impact of secondary carbon nanofillers on the electrical and thermal conductivity, thermal stability, and mechanical properties of hybrid conductive polymer composites (CPC) based on high loadings of synthetic graphite and epoxy resin. Two different carbon nanofillers were chosen for the investigation—low-cost multi-layered graphene nanoplatelets (GN) and carbon black (CB), which were aimed at improving the overall performance of composites. The samples were obtained by a simple, inexpensive, and effective compression molding technique, and were investigated by the means of, i.a., scanning electron microscopy, Raman spectroscopy, electrical conductivity measurements, laser flash analysis, and thermogravimetry. The tests performed revealed that, due to the exceptional electronic transport properties of GN, its relatively low specific surface area, good aspect ratio, and nanometric sizes of particles, a notable improvement in the overall characteristics of the composites (best results for 4 wt % of GN; σ = 266.7 S cm−1; λ = 40.6 W mK−1; fl. strength = 40.1 MPa). In turn, the addition of CB resulted in a limited improvement in mechanical properties, and a deterioration in electrical and thermal properties, mainly due to the too high specific surface area of this nanofiller. The results obtained were compared with US Department of Energy recommendations regarding properties of materials for bipolar plates in fuel cells. As shown, the materials developed significantly exceed the recommended values of the majority of the most important parameters, indicating high potential application of the composites obtained.


2021 ◽  
Author(s):  
HASHIM AL MAHMUD ◽  
, MATTHEW RADUE ◽  
WILLIAM PISANI ◽  
GREGORY ODEGARD

The impact on the mechanical properties of unidirectional carbon fiber (CF)/epoxy composites reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and Functionalized Graphene Oxide (FGO) are investigated in this study. The localized reinforcing effect of each of the graphene nanoplatelet types on the epoxy matrix is predicted at the nanoscale-level by molecular dynamics. The bulk-level mechanical properties of unidirectional CF/epoxy hybrid composites are predicted using micromechanics techniques considering the reinforcing function, content, and aspect ratios for each of the graphene nanoplatelets. In addition, the effect of nanoplatelets dispersion level is also investigated for the pristine graphene nanoplatelets considering a lower dispersion level with four layers of graphene nanoplatelets (4GNP). The results indicate that the shear and transverse properties are significantly affected by the nanoplatelet type, loading and aspect ratio. The results of this study can be used in the design of hybrid composites to tailor specific laminate properties by adjusting nanoplatelet parameters.


Materials ◽  
2004 ◽  
Author(s):  
Hiroyuki Hamada ◽  
Asami Nakai ◽  
Kazuya Eto ◽  
Kenichi Sugimoto

For the purpose of more safety boats, the large thickness of outer plates is required to increase flexural stiffness, strength and impact properties. Some problems in mechanical properties are generated by increasing in thickness because the effect of interlaminar shearing of Thick-composites on whole mechanical properties is greater than that of thin-composites. We have investigated the matrix hybrid composite with two kinds of unsaturated polyester, one was hard type resin with low toughness and the other was flexible type resin with low modulus and high toughness. In this study, matrix hybrid composite was focused and applied to Thick-composites. First, the flexural properties were investigated and the micro fracture progress was precisely observed with in-situ observation using replica method. Then, impact properties of the Thick-composites were examined and the availability of matrix hybrid composite was investigated. It was concluded that the matrix hybrid composite achieved high performance in both static and impact load.


2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.


2011 ◽  
Vol 197-198 ◽  
pp. 1100-1103
Author(s):  
Jian Li

A polyurethane/clay (PU/clay) composite was synthesized. The microstructure of the composite was examined by scanning electron microscopy. The impact properties of the composite were characterized by impact testing. The study on the structure of the composite showed that clays could be dispersed in the polymer matrix well apart from a few of clusters. The results from mechanical analysis indicated that the impact properties of the composite were increased greatly in comparison with pure polyurethane. The investigation on the mechanical properties showed that the impact strength could be obviously increased by adding 20 wt% (by weight) clay to the matrix.


2020 ◽  
pp. 152808372092148 ◽  
Author(s):  
Mansour B Bigdilou ◽  
Reza Eslami-Farsani ◽  
Hossein Ebrahimnezhad-Khaljiri ◽  
Mohammad A Mohammadi

In the present study, the effect of adding various percentage (0.1, 0.3, 0.5, and 0.9 wt.%) of carbon nanotubes on the impact properties of hybrid composites reinforced with the different stacking sequence of Kevlar fibers and ultrahigh molecular weight polyethylene was investigated. The obtained results showed that the composite with the configuration of sandwiched ultrahigh molecular weight polyethylene layers by Kevlar layers had the higher impact properties as compared with other hybrid configurations. Adding 0.1 wt.% carbon nanotubes in this configuration was caused to increase the normalized absorbed energy more than 6.5 times. The fracture surface of this configuration showed that the branching and expanding the damage area were the dominant mechanisms for the energy absorption of impactor. Also, the field emission scanning electron microscope illustrated that the carbon nanotubes by bridging, pulling out, and fracturing mechanisms increased the capability of energy absorption in the hybrid composites.


2011 ◽  
Vol 19 (9) ◽  
pp. 725-732
Author(s):  
Shigeki Hikasa ◽  
Kazuya Nagata ◽  
Yoshinobu Nakamura

The influences of combined elastomers on impact properties and morphology of polypropylene (PP)/elastomer/CaCO3 ternary composites were investigated. In the case that polystyrene- block-poly(ethylene-butene)- block-polystyrene triblock copolymer (SEBS) and poly(ethylene- co-octene) (EOR) were used as elastomers, a sea-island structure consisting of EOR dispersed phase and SEBS continuous phase was formed. The elastomer and the CaCO3 particles were separately dispersed in PP matrix. In the case that carboxylated SEBS (C-SEBS) and EOR were used, the C-SEBS particles were dispersed in the EOR particles. Almost all of the CaCO3 particles were dispersed in the PP matrix, although some of the CaCO3 particles were dispersed in the C-SEBS/EOR combined particles. Impact strength improved with an increase of incorporated CaCO3 particles. The effect of elastomer on the impact strength was SEBS ≥ SEBS/EOR > EOR = C-SEBS/EOR > C-SEBS. The morphology formed by elastomer and CaCO3 particles strongly affected the impact properties of the ternary composites.


2018 ◽  
Vol 774 ◽  
pp. 410-415 ◽  
Author(s):  
Kazuto Tanaka ◽  
Ken Uzumasa ◽  
Tsutao Katayama

Carbon fiber reinforced thermoplastics (CFRTP) are expected to be used as a structural material for aircraft and automobiles not only for their mechanical properties such as high specific strength and high specific rigidity but also for their high recyclability and short molding time. Generally, in a composite material having a laminated structure, interlaminar delamination is often caused by an out-of-plane impact, so the interlayer property plays an important role in the mechanical properties. It has been reported that the fiber/matrix interfacial strength increases by grafting carbon nanotubes (CNT) on the carbon fiber surface. In this study, CNT grafted carbon fibers were used for reinforcement of CFRTP laminate for the improvement of impact properties of CFRTP laminates. The impact absorbed energy of the CFRTP laminate using CNT grafted carbon fibers as reinforcing fiber was higher than that using untreated CF.


2014 ◽  
Vol 919-921 ◽  
pp. 791-794
Author(s):  
Lin Ma

Plane strain problem is currently prevalent in the loess engineering. However, this problem still using conventional triaxial test method for processing. So the paper conducted the plain strain test, analyze differences in plane strain experiments with conventional triaxial experiments under different moisture content and confining pressure. Research shows two points, the first one is the impact on the strength of the soil is more under moisture content than confining pressure, the other is that the soil strength under the plane strain condition is significantly greater than conventional triaxial conditions. It shows that the results were conservative under the plane strain problem at past. It played a certain role in guiding the engineering.


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