The influence of the Sc3+ dopant on the transmittance of (Y, Er)3Al5O12 ceramics

2021 ◽  
Author(s):  
Elena Dobretsova ◽  
Vadim Zhmykhov ◽  
Sergey Kuznetsov ◽  
Irina Chikulina ◽  
Marina Nikova ◽  
...  

The substitution of Al3+ with the larger Sc3+ in the Er:YSAG structure leads to improved elastic–plastic properties. The optical transmittance of the ceramics is affected strongly by including Sc3+ and is increased to up to 60% at about 1.5 μm.

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Sergei Alexandrov ◽  
Elena Lyamina ◽  
Yeong-Maw Hwang

The present paper concerns the general solution for finite plane strain pure bending of incompressible, orthotropic sheets. In contrast to available solutions, the new solution is valid for inhomogeneous distributions of plastic properties. The solution is semi-analytic. A numerical treatment is only necessary for solving transcendent equations and evaluating ordinary integrals. The solution’s starting point is a transformation between Eulerian and Lagrangian coordinates that is valid for a wide class of constitutive equations. The symmetric distribution relative to the center line of the sheet is separately treated where it is advantageous. It is shown that this type of symmetry simplifies the solution. Hill’s quadratic yield criterion is adopted. Both elastic/plastic and rigid/plastic solutions are derived. Elastic unloading is also considered, and it is shown that reverse plastic yielding occurs at a relatively large inside radius. An illustrative example uses real experimental data. The distribution of plastic properties is symmetric in this example. It is shown that the difference between the elastic/plastic and rigid/plastic solutions is negligible, except at the very beginning of the process. However, the rigid/plastic solution is much simpler and, therefore, can be recommended for practical use at large strains, including calculating the residual stresses.


2013 ◽  
Vol 592-593 ◽  
pp. 610-613
Author(s):  
Sina Amiri ◽  
Nora Lecis ◽  
Andrea Manes ◽  
Davide Mombelli ◽  
Marco Giglio

Different approaches have been proposed in order to determine the material behavior of ductile materials. Since, the mechanical properties of a mechanical component are modified during manufacturing process due to plastic deformation, heat treatment and etc, a non-destructive indentation experimental procedure addressed to predict the elastic-plastic properties of material after manufacturing process is of interest. This is especially true for small size components where it is complex to extract specimens to test on standard test system. Based on dimensionless analysis and the concept of a representative strain, different approaches have been proposed to determine the material properties of power law materials by using indentation process. In this work, the Johnson-Cook (JC) constitutive model of the aluminum alloy Al6061-T6 is characterized by means of a well-defined optimization procedure based on micro-indentation testing and high fidelity finite element models and an optimization procedure but without the concept of dimensionless analysis and a representative strain. This methodology allows determining a set of JC constants for Al6061-T6. The obtained results have good agreement with parameters calibrated by means of universal standard tests and reverse engineering approach.


2010 ◽  
Vol 103 (2) ◽  
pp. 493-496 ◽  
Author(s):  
S. K. Deb Nath ◽  
Hironori Tohmyoh ◽  
M. A. Salam Akanda

2018 ◽  
Vol 31 (8) ◽  
pp. 831-841 ◽  
Author(s):  
Yong Jiang ◽  
Yang Li ◽  
Yun-Fei Jia ◽  
Xian-Cheng Zhang ◽  
Jian-Ming Gong

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
S. K. Deb Nath ◽  
Sung-Gaun Kim

At four different strain rates, the tensile stress strain relationship of single-walled 12-12 CNT with aspect ratio 9.1 obtained by Rebo potential (Brenner, 1990), Airebo potential (Stuart et al., 2000), and Tersoff potential (Tersoff, 1988) is compared with that of Belytschko et al. (2002) to validate the present model. Five different empirical potentials such as Rebo potential (Brenner, 1990), Rebo potential (Brenner et al., 2002), Inclusion LJ with Rebo potential (Brenner, 1990), Airebo potential (Stuart et al., 2000), and Tersoff potential (Tersoff, 1988) are used to simulate CNT subjected to axial tension differing its geometry at high strain rate. In Rebo potential (Mashreghi and Moshksar, 2010) only bond-order term is used and in Rebo potential (Brenner et al., 2002) torsional term is included with the bond-order term. At high strain rate the obtained stress strain relationships of CNTs subjected to axial tension differing its geometries using five different potentials are compared with the published results and from the comparison of the results, the drawback of the published results and limitations of different potentials are evaluated and the appropriate potential is selected which is the best among all other potentials to study the elastic, elastic-plastic properties of different types of CNTs. The present study will help a new direction to get reliable elastic, elastic-plastic properties of CNTs at different strain rates. Effects of long range Van der Waals interaction and torsion affect the elastic, elastic-plastic properties of CNTs and why these two effects are really needed to consider in bond-order Rebo potential (Brenner, 1990) to get reliable elastic, elastic-plastic properties of CNTs is also discussed. Effects of length-to-diameter ratio, layering of CNTs, and different empirical potentials on the elastic, elastic-plastic properties of CNTs are discussed in graphical and tabular forms with published results as a comparative manner to understand the nanomechanics of CNTs under tension using molecular dynamics simulation.


Author(s):  
Subhasis Mukherjee ◽  
Abhijit Dasgupta

There are various specimen configurations available in the literature for characterizing the mechanical behavior of solder interconnect materials. An ideal test specimen should use a simple geometry to minimize the complexity of the stress analysis and which produces a uniform material response throughout the test material. In the thermo-mechanical micro scale (TMM) test used in this study, we use a simple, notched shear specimen, based on a concept originally proposed by Iosipescu [1967] [1], which produces a very uniform shear stress field in the solder joint volume [Reinikainen et al., 1998] [2]. Our modified Iosipescu specimen comprises of two oxygen free, high conductivity (OFHC) copper platens soldered together and loaded in simple shear. The solder joint in this specimen is only 180 microns wide to capture the length scale effects of functional solder interconnects. This study examines the effects of dimensional variabilities of this modified Iosipescu specimen on the shear stress distribution in the solder joint. Variabilities encountered in these specimens include: (i) fillets at the V-notches, caused by excess solder; (ii) offset between the two copper platens along the loading direction; (iii) taper of the solder joint due to lack of parallelism of the edges of the copper platens; and (iv) misalignment between the specimen centerline and loading axis of the TMM test frame due to mounting variability. Detailed parametric studies of these four dimensional variations in the TMM specimen are conducted using a simple two-dimensional elastic-plastic finite element model. The uniformity of the shear stress field in the specimen is investigated and the variation in the derived stress-strain curves is examined, as a function of the dimensional variabilities described above.


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