Adjusting the Flexibility of Fabric Reinforced Composite Laminates Using Experimental Design

2015 ◽  
Vol 812 ◽  
pp. 181-187
Author(s):  
T. Molnar ◽  
V. Baranyai ◽  
S. Kemény ◽  
Gy. Bánhegyi ◽  
József Szabó

The objective of our work is to improve the mechanical stiffness of fiber reinforced laminates. The stiffness can be characterized by flexural and tensile moduli or their derivation. We applied design of experiments (DOE) to achieve our goals, because to solve the existing analytical and numerical models is complicated.We examined the effects of the following parameters: a) composition of reinforce materials (solely carbon, or carbon and glass combination), b) modulus of resin, c) mass ratio of resin-reinforcement, d) order of layers.The samples manufactured on the basis of DOE were investigated mechanically (flexural and tensile moduli measurements) and morphologically (scanning electron microscopy). We compared the measured modulus results to calculated values.

2011 ◽  
Vol 332-334 ◽  
pp. 1352-1356
Author(s):  
Li Wei Liu ◽  
Wei Min Kang ◽  
Bo Wen Cheng

In this paper polyurethane (PU) / polyaniline (PANI) nanofibers were successfully prepared via electrospinning with N, N-dimethylformamide (DMF) and tetrahydrofuran (THF) mixture (1:2 mass ratio). The morphology, diameter and structure of the electrospun nanofibers were examined by scanning electron microscopy (SEM) and the diameter distribution of nanofibers was measured by Image-Pro Plus. Results indicate that the morphology, diameter and uniformity of the fibers were influenced by solution concentration, applied voltage, capillary–screen distance and flow rate greatly, and the finer and uniform nanofibers were electrospun from total solid content of the spinning solutions at 8 wt. %, PU and PANI with ratio of 10/1 (w/w), the spinning voltage at 35 kV, the collecting distance at 15 cm and the extruding speed at 6 ml/h.


2021 ◽  
Vol 21 (10) ◽  
pp. 5329-5336
Author(s):  
Hongjun Chen ◽  
Zeyang Xue ◽  
Chunhu Yu ◽  
Yajing Mao ◽  
Fanglv Qiu ◽  
...  

Vanadium doped lanthanum bismuthate nanorods with vanadium ratio of 1%, 3%, 5% and 10 wt.% were fabricated through the hydrothermal method using sodium orthovanadate as vanadium source. Vanadium doped lanthanum bismuthate nanorod products were analyzed by scanning electron microscopy, X-ray diffraction pattern and diffuse reflection spectrum. X-ray diffraction patterns show that vanadium in the vanadium doped lanthanum bismuthate nanorods exists as triclinic Bi23V4O44.5 and monoclinic LaVO4 phases. Scanning electron microscopy observations show that the size and micro-morphology of the vanadium doped products are closely relative to the vanadium mass ratio. The length of the vanadium doped nanorods decreases and the morphology changes from nanorods to irregular nanoparticles with increasing the vanadium mass ratio. Solid UV-vis diffuse reflectance measurement shows that the bandgap value of the doped lanthanum bismuthate nanorods is narrowed from 2.37 eV to 2.25 eV after the vanadium doping ratio is increased from 1% to 10%. The doped lanthanum bismuthate nanorods illustrate enhanced photocatalytic performance for methylene orange (MO) removal with the irradiation of sunlight. The catalytic performance for MO removal depends on the irradiation time, vanadium content and dosage of the nanorods. The doped lanthanum bismuthate nanorods with the vanadium mass ratio of 10% possess the best MO catalytic degradation performance.


2012 ◽  
Vol 232 ◽  
pp. 39-44
Author(s):  
Y. Şahin ◽  
K. Emre Öksüz

Aluminium alloys (Al2014 and Al2124 alloy) and their composites containing 10wt.% Al2O3 with 3 µm and 43 µm sizes of particles have been produced by powder metallurgy (PM) method and the microstructure and hardness were investigated. Scanning electron microscopy (SEM) investigation showed a nearly uniform distribution of the Al2O3 particles within the Al2124 alloy matrix although some porosities were found in the Al2014 alloy matrix. Furthermore, it was found that the macrohardness of Al2124 alloy composite improved highly in comparison to that of Al2014 alloy due to fine of microstructure and increased hardness. The hardnesses of both MMCs increased with increasing the particle sizes.


2012 ◽  
Vol 512-515 ◽  
pp. 744-747 ◽  
Author(s):  
Yan Yan Wang ◽  
Kai Liu ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Rui Xiang Liu ◽  
...  

The ZrB2-SiC composite ceramic was prepared using Al2O3 and Y2O3 as additives through pressureless sintering under 1800°C. The electrical and mechanical properties were studied with the different mass ratio of ZrB2 and SiC. The microstructure and phase transformation of the ZrB2-SiC composites ceramic were characterized by scanning electron microscopy. Results show that the densities of the samples are decreased with the decrease of the mass ratio of ZrB2 and SiC while the resistivities are increased. When the mass ratio of ZrB2 and SiC is 4 the resistivity reaches 14μΩ•mm while the density is 4.85g/cm3. When the mass ratio of ZrB2 and SiC is13:7, the flexural strength reaches the max value and toughness reaches the minimum value. The flexural strength reaches 233Mpa and the toughness reaches 4.51 Mpa• m 1/2. The changes of the properties of the ceramic were analyzed through the microstructure and the conduction mechanism was studied.


Author(s):  
Nur Aliya Ibrahim ◽  
Rabihah Alawi ◽  
Yanti Johari ◽  
Nor Aidaniza Abdul Muttlib ◽  
Mohd Nazrulhuzaimi Md Yusoff

Abstract Objective This study aimed to evaluate the flexural and compressive strength of kenaf-reinforced composite resin as well as analyze the length and diameter of kenaf fibers and their surface topography. Materials and Methods Kenaf fibers were alkaline treated and wetted with coupling agent. Kenaf-reinforced composite resin was fabricated manually. Specimens for kenaf-reinforced composite resin (Tetric N Flow [Ivoclar Vivadent, Liechtenstein] + 2% kenaf) and control group (Tetric N Flow [Ivoclar Vivadent, Liechtenstein]) were prepared using stainless steel molds with dimension of 25 mm × 2 mm × 2 mm and 6 mm × 4 mm for flexural and compressive strength tests, respectively, and tested using Instron Universal Testing Machine (Shimadzu, Japan). Raw kenaf fibers, treated kenaf fibers, and fractured sample from flexural strength test were analyzed using scanning electron microscopy (SEM) (FEI Quanta FEG 450, United States). Data were analyzed using independent sample t-test. Significant level was set at p < 0.05. Results Kenaf-reinforced composite resin has a lower flexural and compressive strength than the control group (p < 0.05). SEM analysis revealed the average fibers’ length to be 1.24 mm and diameter ranging from 6.56 to 12.9 μm. The fibers dispersed in composite as single strand or a bundle with a minimal gap between fibers and composite. Conclusion Flexural and compressive strengths of kenaf-reinforced composite resin were lower than the control group, despite some adaptation between kenaf fibers and composite noted. The fibers’ length and diameter were reasonable for the dispersion in the resin matrix; however, additional treatments of kenaf are required for a favorable result.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


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