scholarly journals Measurement and calculation of the parameters of mechanical properties of silicone rubber

Author(s):  
S.A. Muslov ◽  
◽  
D.I. Polyakov ◽  
A.I. Lotkov ◽  
A.G. Stepanov ◽  
...  

The measurement and calculation of the mechanical properties of silicone rubber used for the manufacture of a prosthesis for the auricle of patients based on dental CAD/CAM systems, using a hybrid technology that includes traditional and digital methods of manufacturing medical devices were performed. Mechanical tensile tests were carried out in a climatic chamber at various temperatures: -20; 0; 25; 40 °C. All mechanical characteristics of silicone rubber lay in a very limited range of values and monotonically decreased with increasing test temperature from -20 to + 45°C. At the same time, the elastic characteristics (elastic modulus) decreased by 1.55, deformation (fracture deformation) - by 1.98, strength (tensile strength) - by 2.37 times. The average values of tensile strength were 6.54 MPa, fracture deformation - 1480.61%, modulus of elasticity - 0.53 MPa, and temperature gradient: 0.08 MPa/deg, 14.8%/deg and 0.004 MPa/deg, respectively. In the framework of the Mooney - Rivlin hyperelastic model, the coefficients of the model C 01 and C 10 are determined, which can be used as parameters when performing simulation modeling of the stress-strain state of prostheses. Based on the data obtained, an assessment was made of the cross-linked density of the silicone rubber material as a synthetic polymer. It turned out to be equal to 0.49.

Author(s):  
Aleksandra Towarek ◽  
Wojciech Jurczak ◽  
Joanna Zdunek ◽  
Mariusz Kulczyk ◽  
Jarosław Mizera

AbstractTwo model aluminium-magnesium alloys, containing 3 and 7.5 wt.% of Mg, were subjected to plastic deformation by means of hydrostatic extrusion (HE). Two degrees of deformation were imposed by two subsequent reductions of the diameter. Microstructural analysis and tensile tests of the materials in the initial state and after deformation were performed. For both materials, HE extrusion resulted in the deformation of the microstructure—formation of the un-equilibrium grain boundaries and partition of the grains. What is more, HE resulted in a significant increase of tensile strength and decrease of the elongation, mostly after the first degree of deformation.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5042
Author(s):  
Jaeyoung Kwon ◽  
Junhyeok Ock ◽  
Namkug Kim

3D printing technology has been extensively applied in the medical field, but the ability to replicate tissues that experience significant loads and undergo substantial deformation, such as the aorta, remains elusive. Therefore, this study proposed a method to imitate the mechanical characteristics of the aortic wall by 3D printing embedded patterns and combining two materials with different physical properties. First, we determined the mechanical properties of the selected base materials (Agilus and Dragonskin 30) and pattern materials (VeroCyan and TPU 95A) and performed tensile testing. Three patterns were designed and embedded in printed Agilus–VeroCyan and Dragonskin 30–TPU 95A specimens. Tensile tests were then performed on the printed specimens, and the stress-strain curves were evaluated. The samples with one of the two tested orthotropic patterns exceeded the tensile strength and strain properties of a human aorta. Specifically, a tensile strength of 2.15 ± 0.15 MPa and strain at breaking of 3.18 ± 0.05 mm/mm were measured in the study; the human aorta is considered to have tensile strength and strain at breaking of 2.0–3.0 MPa and 2.0–2.3 mm/mm, respectively. These findings indicate the potential for developing more representative aortic phantoms based on the approach in this study.


2021 ◽  
Author(s):  
Wenhuan Zhang ◽  
Zhaoping Deng ◽  
Hongwei Yuan ◽  
Shikai Luo ◽  
Huayin Wen ◽  
...  

AbstractIn this paper, silicone rubber materials with foam/solid alternating multilayered structures were successfully constructed by combining the two methods of multilayered hot-pressing and supercritical carbon dioxide (SCCO2) foaming. The cellular morphology and mechanical properties of the foam/solid alternating multilayered silicone rubber materials were systematically studied. The results show that the growth of the cell was restrained by the solid layer, resulting in a decrease in the cell size. In addition, the introduction of the solid layer effectively improved the mechanical properties of the microcellular silicone rubber foam. The tensile strength and compressive strength of the foam/solid alternating multilayered silicone rubber materials reached 5.39 and 1.08 MPa, which are 46.1% and 237.5% of the pure silicone rubber foam, respectively. Finite element analysis (FEA) was applied and the results indicate that the strength and proportion of the solid layer played important roles in the tensile strength of the foam/solid alternating multilayered silicone rubber materials. Moreover, the small cellular structures in silicone rubber foam can provided a high supporting counterforce during compression, meaning that the microcellular structure of silicone rubber foam improved the compressive property compared to that for the large cellular structure of silicone rubber foam.


2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.


2010 ◽  
Vol 139-141 ◽  
pp. 180-184
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Li Hui Lang

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperatures (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure of homogenized AZ80 alloy have been investigated through the tensile tests and via metallographic microscope observation. The results show that the alloy’s grain is small and small amounts of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength at 330°C. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, the tensile strength increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.


Author(s):  
E.N. Kablov ◽  
◽  
G.S. Kulagina ◽  
G.F. Zhelezina ◽  
S.L. Lonskii ◽  
...  

This paper studies a polymer composite material - a unidirectional organoplastic based on Rusar-NT aramid fiber and a melt epoxy-polysulfone binder. Organoplastic has the following mechanical properties: tensile strength 2060 MPa, Young's modulus 101 GPa. The microstructure of the fiber and the polymer matrix in the organoplastic samples was studied before and after tensile tests. The features of the formation of the binder structure depending on the packing density of the fibers in organoplastics have been determined. The nature of the destruction of fibers and polymer matrix caused by the uniaxial tension has been studied.


2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.


2000 ◽  
Vol 9 (4) ◽  
pp. 096369350000900 ◽  
Author(s):  
C. Gonzalez ◽  
J. Llorca

The effect of processing on the mechanical properties of Sigma 1140+ SiC fibres was studied through tensile tests carried out on pristine Sigma 1140+ SiC fibres and on fibres extracted from a Ti-6A1-4V-matrix composite. The elastic modulus and the tensile strength were computed after measuring carefully the fibre diameter. The characteristic fibre strength was reduced by 20% and the Weibull modulus by half during composite processing. The analysis of the fracture surfaces in the scanning electron microscope showed that the strength-limiting defects were located around the tungsten core in pristine fibres and predominantly at the surface in fibres extracted from the composite panels. These latter defects were nucleated by the mechanical stresses generated on the fibres during the panel consolidation.


DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 156-163 ◽  
Author(s):  
Leidy Johana Quintero Giraldo ◽  
Luis Javier Cruz ◽  
Jaime Alexis García ◽  
Alejandro Alcaraz ◽  
Eugenia González ◽  
...  

In this article, bamboo fibre bundles of "Guadua Angustifolia Kunth" specie were isolated from different locations of the basa zone: upper, middle and lower, through mechanical extraction method. The elastic modulus and the tensile strength were obtained with preliminary tensile tests. Applying the statistical analysis known as ANOVA, it was determined that the mechanical properties are similar in all the extension of the basa zone. From there, fibre bundles were extracted randomly, and a part of the fibre bundles was treated with NaOH (mercerization). Later, tensile tests with different calibration lengths were made for calculate the elastic modulus and the tensile strength of the treated and untreated fibre bundles. Best results belonged to the treated fibre bundles. A good correspondence between the results obtained in this work and the results reported in the literature was concluded. 


2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.


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