scholarly journals Braiding Thermoplastic and Glass Fibers in Composite Dental Post Improves Their Mechanical Compatibility, In Vitro Experiment

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2294
Author(s):  
Esraa M. Abdelkader ◽  
Khaled Nassar ◽  
Juan Melchor ◽  
Guillermo Rus

Mechanical compatibility with the human dentin is a considerable issue when fabricating dental fiber posts. To this purpose, this study introduces a new method of fabricating compatible dental posts using braiding techniques of thermoplastic fibers (matrix) with glass fibers (reinforcement). Fifty fiber-reinforced composite (FRC) posts of thermoplastic yarns polypropylene (PP) braided with continuous filaments glass fibers (GFs) for reinforcement, varying in fiber volume fraction (FVF), and core types are fabricated and tested. Posts are performed using a braiding machine, and braids are placed in an aluminum mold. The filled mold is playced inside an oven at the melting temperature of the polypropylene to produce the final post’s shape. An ultrasonic test is conducted to measure the shear modulus and Young’s modulus of FRC post specimens by measuring the velocities of both the P-wave and S-wave. In order to ensure the accuracy of the measurements, each sample is measured three times, and then the means and standard deviations of each sample are calculated before analyzing the test results using the means of two steps, namely, clustering and comparing the P and R² values of each cluster, which revealed that FVF, fiber mass, and core type of the specimen had a significant effect on the resulted Young’s and shear modulus. The results indicate that the proposed method can fabricate competitive dental posts with regard to different fabricating variables. The samples show Young’s modulus ranges of from 10.08 GPa to 31.83 GPa. The following tested hypothesis is supported: the braiding technique of thermoplastic fibers with glass fibers will improve the mechanical compatibility of the resulting posts (ex vivo).

2017 ◽  
Vol 865 ◽  
pp. 366-372
Author(s):  
Jing Sen Liu ◽  
Hai Bo Li ◽  
Guo Kai Zhang ◽  
Jian Deng

In order to improve the accuracy of the rock mechanical parameters, the correlations among physical and mechanical parameters were investigated. A large number of laboratory testing results curried out on 408 rock specimens including metamorphic rocks, sedimentary rocks and igneous rocks. Through the statistical analysis of the laboratory test data, several regression equations among rock material parameters were established. The research suggests that, in addition to Poisson's ratio, the mechanical parameters (unconfined compressive strength (UCS), elastic Young’s modulus, shear modulus) relate well to physical parameters (porosity, P-wave velocity), and the relationships are mainly described by power and exponential correlations which have good squared regression coefficients. The correlation between elastic Young’s modulus and dynamic elastic modulus was established, as well as the relationship between shear modulus and dynamic shear modulus.


2015 ◽  
Vol 1760 ◽  
Author(s):  
Joung Wook Kim ◽  
Kyosuke Yoshimi ◽  
Hirokazu Katsui ◽  
Takashi Goto

ABSTRACTThe effect of Ti addition on the density and microstructure development of MoSiBTiC alloy was investigated. Two kinds of MoSiBTiC alloys with the composition of Mo-5Si-10B-10Ti-10C (10Ti alloy) and Mo-5Si-10B-15Ti-10C (15Ti alloy) (at. %) were prepared by conventional arc-melting. The primary phase of as-cast 10Ti and 15Ti alloys was (Ti,Mo)C, and there were two eutectic phases of Moss + (Ti,Mo)C and Moss + T2 + (Ti,Mo)C in the alloys. In addition, 10Ti alloy had a Moss + T2 + (Mo,Ti)2C eutectic. There was no Moss + T2 + (Mo,Ti)2C eutectic in the 15Ti alloy, and thus it is apparent that the (Mo,Ti)2C formation was suppressed by 5 at. % Ti addition. The volume fraction of (Ti,Mo)C increased and thus the density reduced from 8.78 to 8.43 g/cm3 with the Ti addition. In all constituent phases, Ti concentration increased while Mo concentration decreased. In spite of the changes, hardness, Young’s modulus and shear modulus were hardly changed. Therefore, Ti addition seems to be effective to further lower the density without deteriorating mechanical properties of the MoSiBTiC alloy.


2005 ◽  
Vol 502 ◽  
pp. 201-204 ◽  
Author(s):  
Tsunemichi Imai ◽  
Shang Li Dong ◽  
Ichinori Shigematsu ◽  
Naobumi Saito ◽  
Kazutaka Suzuki ◽  
...  

The XN-05C/2017, XN-05C/MESO-10 and BGC152/MESO-10 aluminum composites reinforced by low young’s modulus amorphous carbon fiber and particle, respectively, were fabricated by a PM route followed by hot extrusion and rolling in this study. The mechanical properties of the prepared composites were investigated subsequently. The XN-05C/2017 and XN-05C/MESO-10 were found to exhibit low elastic modulus of 50~60GPa within the fiber volume fraction of 0.10~0.15, while the BGC152/MESO-10 shows a data of 50GPa with a particle volume fraction of 0.10. The tensile strength of XN-05C/MESO-10 was evaluated to be 400~600MPa in the case of Vf=0.10~0.15, and become to decease with increasing fiber volume fraction. Damping application would be a potential consideration for the amorphous carbon fiber reinforced aluminum composites.


1982 ◽  
Vol 49 (3) ◽  
pp. 536-540 ◽  
Author(s):  
Y. Takao ◽  
T. W. Chou ◽  
M. Taya

This paper examines the effective longitudinal Young’s modulus of composites containing misoriented short fibers. The analysis is based on the Eshelby’s equivalent inclusion method and the average induced strain approach of Taya, Mura, and Chou. The present approach is unique in that it takes into account the interactions among fibers at different orientations. Numerical results are presented to demonstrate the effects of fiber elastic property, aspect ratio, volume fraction, and orientation distribution function on composite Young’s modulus. Fiber orientation distribution has a more significant effect on composite longitudinal Young’s modulus than fiber volume friction, within the range examined.


Author(s):  
SHULEI SUN ◽  
XIONGQI PENG ◽  
ZAOYANG GUO

Polymer matrix filled with ferromagnetic particles is a class of smart materials whose mechanical properties can be changed under different magnetic field. They are usually referred to as magnetorheological elastomers (MREs). A finite element simulation was presented to describe the mechanical behavior of MREs with the nonlinearity of the particle magnetization being incorporated. By introducing the Maxwell stress tensor, a representative volume element (RVE) was proposed to calculate the Young's modulus and shear modulus of MREs due to the applied magnetic field. The influences of the applied magnetic field and the particle volume fractions in the shear modulus and Young's modulus were studied. Results show that the shear modulus increases with the magnitude of the applied magnetic field, while the Young's modulus decreases.


2021 ◽  
Vol 21 (2) ◽  
pp. 7-11
Author(s):  
Ahmed Mansoor Abbood ◽  
Haider K. Mehbes ◽  
Abdulkareem. F. Hasan

In this study, glass-filled epoxy functionally graded material (FGM) was prepared by adopting the hand lay-up method. The vertical gravity casting was used to produce a continuous variation in elastic properties. A 30 % volume fraction of glass ingredients that have mean diameter 90 μm was spread in epoxy resin (ρ = 1050 kg/m3). The mechanical properties of FGM were evaluated according to ASTM D638. Experimental results showed that a gradually relationship between Young’s modulus and volume fraction of glass particles, where the value of Young’s modulus at high concentration of glass particles was greater than that at low concentration, while the value of Poisson’s ratio at high concentration of glass particles was lower than that at low concentration. The manufacture of this FG beam is particularly important and useful in order to benefit from it in the field of various fracture tests under dynamic or cyclic loads.


1986 ◽  
Vol 108 (2) ◽  
pp. 141-148 ◽  
Author(s):  
H. C. Park ◽  
Y. K. Liu ◽  
R. S. Lakes

The elastic Young’s modulus and shear modulus of bone-particle impregnated polymethylmethacrylate (PMMA) has been measured experimentally at room temperature as a function of bone particle concentration. It was found that the moduli increased with increasing bone particle content. This increase was less than the stiffness increase predicted by higher-order composite theory [1, 2] under the assumption of perfect bonding between particles and matrix. It was concluded that a bond existed but that it was not a perfect bond.


2011 ◽  
Vol 146 ◽  
pp. 12-26 ◽  
Author(s):  
A. Gherissi ◽  
R.Ben Cheikh ◽  
E. Dévaux ◽  
Fethi Abbassi

In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.


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