Impacted of Vacuum Bag Woven Kenaf/Fiberglass Hybrid Composite

2014 ◽  
Vol 660 ◽  
pp. 572-577
Author(s):  
Syarifah Yunus ◽  
Z. Salleh ◽  
M.A. Aznan ◽  
M.N. Berhan ◽  
A. Kalam ◽  
...  

This paper discusses the mechanical properties of woven kenaf/fiberglass hybrid composites which has been fabricating using vacuum bag technique. Kenaf fiber had chosen among others natural fibres due to its excellent mechanical properties and potential natural raw fiber to replace plastic or tobacco in manufacturing a multitude of products for the construction, automotive, textile and advanced technology sectors. This study investigates post impact tensile of kenaf hybrid composites and its surface fractured. The impact energy used consists of 4J, 6J, 8J, 12J and 16J. The specimens were clamped between two plate rings with an internal hole diameter of 18mm and impacted with hemispherical nose impactor shape with diameter size of 12.7mm. The results revealed that this kenaf hybrid composite showed significant decreasing of strength and modulus as increasing the impact energy. The damage area affected with fiber fracture occurred much later in fracture process due to high bending stresses.

2016 ◽  
Vol 25 (4) ◽  
pp. 096369351602500 ◽  
Author(s):  
R. Yahaya ◽  
S.M. Sapuan ◽  
M. Jawaid ◽  
Z. Leman ◽  
E.S. Zainudin

Fibre reinforced polymer composites has been used in a variety of applications. Recently, there is increasing interest in the research on natural-synthetic fibre hybrid composite. In this study, water absorption behaviours and impact properties of woven kenaf-Kevlar hybrid composite were evaluated. In all samples, Kevlar (aramid fibres) was kept as the skin layers and kenaf as the core material. The experimental results revealed that the hybrid composites with high kenaf content shows low density (0.88g/m3) and contains a high content of the voids (25.67%). Similar finding observed in water absorption and thickness swelling test as the hybrid composite with higher kenaf content absorb more water absorption and low dimensional stability. Water absorption affects the impact strength of the composites. The impact strength decreased about 45.38 % (from 228.24 to 124.66kJ/m2) in sample H1), whereas, the highest impact strength decreased of about 78.52% (from 179.71 to 38.60 kJ/m2) was observed in sample H5). The result of this study is important for the further utilisation of woven kenaf in hybrid laminate composites.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
R. Ganesamoorthy ◽  
R. Meenakshi Reddy ◽  
T. Raja ◽  
Pradeep Kumar Panda ◽  
Sneha H. Dhoria ◽  
...  

A percentage of natural fibers is used for developing a composite, the materials are quite increasing in recent trends, and they can be a potential replacement of synthetic fibers in the reinforcement phase of hybrid composite. In this research, the combination of natural fibers and synthetic fibers can be used as reinforcement, and epoxy polymer can be used as matrix material. The fibers of Kevlar and Napier grass are reinforced with epoxy matrix to develop a new composite by using conventional hand layup fabrication process and to quantify the effect of this hybrid composite laminate, with five different sequences following. To identify the mechanical properties of this hybrid composite through tensile, flexural, compression strength, impact strength, and hardness tests, among all five samples, sample A was given the maximum mechanical strength, such that the tensile strength is 210 MPa, flexural strength is 165 MPa, the impact energy absorption is 23 J, the average is 40% over the other samples, and, at the same time, the compression strength of sample E is 19 MPa, revealing the negative influence of hybrid composite. The SEM morphology was carried out to identify the failure mode of the hybrid composites.


2019 ◽  
Vol 61 (11) ◽  
pp. 1095-1100 ◽  
Author(s):  
Sivakumar Dhar Malingam ◽  
Kathiravan Subramaniam ◽  
Ng Lin Feng ◽  
Siti Hajar Sheikh MD Fadzullah ◽  
Sivaraos Subramonian

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.


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.


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.


2019 ◽  
Vol 36 (1) ◽  
pp. 47-62
Author(s):  
AR Mohammed ◽  
MS Nurul Atiqah ◽  
Deepu A Gopakumar ◽  
MR Fazita ◽  
Samsul Rizal ◽  
...  

Natural fiber-reinforced composites gained considerable interest in the scientific community due to their eco-friendly nature, cost-effective, and excellent mechanical properties. Here, we reported a chemical modification of kenaf fiber using propionic anhydride to enhance the compatibility with the epoxy matrix. The incorporation of the modified woven and nonwoven kenaf fibers into the epoxy matrix resulted in the improvement of the thermal and mechanical properties of the composite. The thermal stability of the epoxy composites was enhanced from 403°C to 677°C by incorporating modified woven kenaf fibers into the epoxy matrix. The modified and unmodified woven kenaf fiber-reinforced epoxy composites had a tensile strength of 64.11 and 58.82 MPa, respectively. The modified woven composites had highest flexural strength, which was 89.4 MPa, whereas, for unmodified composites, it was 86.8 MPa. The modified woven fiber-reinforced epoxy composites showed the highest value of flexural modulus, which was 6.0 GPa compared to unmodified woven composites (5.51 GPa). The impact strength of the epoxy composites was enhanced to 9.43 kJ m−2 by the incarnation of modified woven kenaf fibers into epoxy matrix. This study will be an effective platform to design the chemical modification strategy on natural fibers for enhancing the compatibility toward the hydrophobic polymer matrices.


2017 ◽  
Vol 904 ◽  
pp. 146-150 ◽  
Author(s):  
Manjunath Shettar ◽  
U. Achutha Kini ◽  
Sathya Shankar Sharma ◽  
Pavan Hiremath

The review is on aimed an insight source for FRP-Nanoclay hybrid composite (nanocomposite) research, which includes basic structure/property, preparation & characterization techniques, mechanical properties and applications of hybrid composites. Key factors are discussed, which are influencing the mechanical properties of nanocomposite with nanoclay addition. Conclusions are also drawn based on the research of nanocomposites and improvement in mechanical properties.


2021 ◽  
Vol 1016 ◽  
pp. 1739-1746
Author(s):  
Yan Mei Li ◽  
Shu Zhan Zhang ◽  
Zai Wei Jiang ◽  
Sheng Yu ◽  
Qi Bin Ye ◽  
...  

The effect of tempering time on the microstructure and mechanical properties of SA738 Gr.B nuclear power steel was studied using SEM, TEM and thermodynamic software, and its precipitation and microstructure evolution during tempering were clarified. The results showed that SA738 Gr.B nuclear power steel has better comprehensive mechanical properties after tempering at 650 °C for 1h. With the extension of the tempering time, M3C transformed into M23C6 with increasing size, which affected the yield strength and impact energy. When the tempering time is 8h ~ 10h, due to the transformation of M3C to M23C6, the composition of matrix around the carbide changed, causing the temperature of Ac1 dropped, forming twin-martensite which deteriorated the impact toughness of the steel.


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