Study of temperature and pressure dependent elastic properties of porous ceramics

2017 ◽  
Vol 142 (4) ◽  
pp. 2546-2546
Author(s):  
Ashoka Karunarathne ◽  
Josh R. Gladden ◽  
Gautam Priyadarshan
Open Physics ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Lili Liu ◽  
Xiaozhi Wu ◽  
Weiguo Li ◽  
Rui Wang ◽  
Qing Liu

AbstractThe high temperature and pressure effects on the elastic properties of the AgRE (RE=Sc, Tm, Er, Dy, Tb) intermetallic compounds with B2 structure have been performed from first principle calculations. For the temperature range 0-1000 K, the second order elastic constants for all the AgRE intermetallic compounds follow a normal behavior: they decrease with increasing temperature. The pressure dependence of the second order elastic constants has been investigated on the basis of the third order elastic constants. Temperature and pressure dependent elastic anisotropic parameters A have been calculated based on the temperature and pressure dependent elastic constants.


1993 ◽  
Vol 6 (2) ◽  
pp. 75-80 ◽  
Author(s):  
M Cankurtaran ◽  
G A Saunders ◽  
U Balachandran ◽  
R B Poeppel ◽  
K C Goretta

2017 ◽  
Vol 09 (05) ◽  
pp. 1750069 ◽  
Author(s):  
Matthias Kulosa ◽  
Matthias Neumann ◽  
Martin Boeff ◽  
Gerd Gaiselmann ◽  
Volker Schmidt ◽  
...  

To correlate the mechanical properties of granular porous materials with their microstructure, typically porosity is being considered as the dominant parameter. In this work, we suggest the average coordination number, i.e., the average number of connections that each grain of the porous material has to its neighboring grains, as additional — and possibly even more fundamental — microstructural parameter. In this work, a combination of stochastic and mechanical modeling is applied to study microstructural influences on the elastic properties of porous ceramics. This is accomplished by generating quasi-two-dimensional (2D) and fully three-dimensional (3D) representative volume elements (RVEs) with tailored microstructural features by a parametric stochastic microstructure model. In the next step, the elastic properties of the RVEs are characterized by finite element analysis. The results reveal that the average coordination number exhibits a very strong correlation with the Young’s modulus of the material in both 2D and 3D RVEs. Moreover, it is seen that quasi-2D RVEs with the same average coordination number, but largely different porosities, only differ very slightly in their elastic properties such that the correlation is almost unique. This finding is substantiated and discussed in terms of the load distribution in microstructures with different porosities and average coordination numbers.


An apparatus has been constructed to subject a film of oil to high transient stresses and rates of shear by applying an impulsive load. The apparatus makes it possible to derive the values of the instantaneous viscosity of the oil through out the duration of the impact and to detect whether the oil exhibits viscoelastic behaviour in these conditions. Typical mineral lubricating oils do not exhibit elastic properties in the apparatus and their behaviour is explicable on the assumption that the viscosity depends on pressure and temperature in the manner observed in the usual types of viscometer. However, when only elementary calculations are made the viscosity appears to be abnormally low. To explain the behaviour adequately, it is necessary to consider the viscosity of the lubricant not only with respect to temperature and pressure but also from place to place and instant to instant through out the impact. When this is done, the theory provides a good description of the behaviour of the system up to the point at which the pressures cause significant deformation of the plates containing the oil film. Two other oils, each having an initial viscosity and pressure coefficient of viscosity well above the range of typical lubricating oils, have been observed to exhibit anomalous behaviour. The evidence is consistent with the supposition that they behave viscoelastically but further work would be required to prove the point.


1996 ◽  
Vol 10 (15) ◽  
pp. 697-703 ◽  
Author(s):  
S.S. BEDI ◽  
M.S. BHANGOO

The expressions for the temperature and pressure derivatives of Second Order Elastic (SOE) constants of elements of earth’s lower mantle i.e. CaO, MgO and SrO have been obtained using a simple method of direct differentiation of expressions of SOE constants which have been suitably modified taking into account three body interaction and thermal phonon pressure. The method provides a direct check to the already known expressions of pressure derivatives of SOE constants using Thurston and Brugger relation. The results obtained at 300° K are found to be in reasonably good agreement with the experiment.


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