scholarly journals Applicability evaluation of the stress-optic law in Newtonian fluids toward stress field measurements

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Daisuke Noto ◽  
Yuji Tasaka ◽  
Jumpei Hitomi ◽  
Yuichi Murai
Keyword(s):  
Stress Field ◽  
Field Measurements ◽  
Newtonian Fluids ◽  
Stress Optic Law ◽  
Applicability Evaluation

Constant Stress Field Measurements Through Thermoelasticity

2013 ◽  
Vol 36 (7) ◽  
pp. 672-683 ◽  
Author(s):  
A. Garinei ◽  
M. Becchetti ◽  
E. Pucci ◽  
G. Rossi
Keyword(s):  
Stress Field ◽  
Field Measurements ◽  
Constant Stress

Extrusion of Polymer Melts and Melt Flow Instabilities. III. Theoretical Analysis of Extrusion through a Slit Die

1969 ◽  
Vol 42 (3) ◽  
pp. 691-699 ◽  
Author(s):  
James L. White
Keyword(s):  
Reynolds Number ◽  
Stress Field ◽  
Viscoelastic Fluid ◽  
Polymer Melts ◽  
Second Order ◽  
Secondary Flows ◽  
Newtonian Fluids ◽  
Creeping Flow ◽  
Flow Instabilities ◽  
Field Problem

Abstract In the previous sections of this paper we have discussed our own and other experimental studies of flow instabilities in the extrusion of polymer melts as well as various theories of the mechanism of initiation of the instability. It is our belief that one of the keys to a deeper understanding of this phenomenon is a fuller analytical understanding of the stress and velocity fields in the composite reservoir, capillary, and extrudate system. It is to this problem that we turn our attention here. The velocity, stress-field problem in the entrance region of a conduit being fed from a reservoir has received considerable attention for Newtonian fluids. Most authors have followed Schlichting and Goldstein in using boundary-layer theory to analyze this problem. While there are a number of such solutions for viscous non-Newtonian and viscoelastic fluids, they are of little interest for polymer melts. This is not only because they represent a high Reynolds number, inertia-dominated asymptote but because they neglect all phenomena occurring in the reservoir feeding the conduit. Of more interest are the low Reynolds number creeping flow solutions for Newtonian fluids which are based upon the work of Sampson (see also Roscoe and Weissberg). A decade ago Tomita published a pioneering analysis of the creeping flow of a viscous non-Newtonian (power-law) fluid into a sharp edge entrance of a capillary. More recently LaNieve and Bogue have analyzed the creeping flow of a Coleman-Noll second order into the capillary entrance. A recent study of the entry problem has been made by Metzner, Uebler, and Chan Man Fong. The related problem of creeping flow of a viscoelastic fluid in a converging channel or cone has been analyzed by Adams, Whitehead, and Bogue and Kaloni. While the former authors computed the stress field for a second-order fluid and an integral constitutive equation in a presumed velocity field, Kaloni actually evaluated velocity profiles and predicted the formation of secondary flows. A more intuitive, but far less rigorous approach to extrusion of a viscoelastic fluid has been taken by Dexter and Dienes and Smith. These authors presume a virgin material to enter a capillary die in fully developed flow and utilize the theory of linear viscoelasticity to evaluate the stress field.

Inversion of Initial Geo-Stress in High and Steep Slope

2012 ◽  
Vol 170-173 ◽  
pp. 1325-1329
Author(s):  
Zhong Fan Yuan ◽  
Pei Hua Xu ◽  
Zhao Rong Ye
Keyword(s):  
Stress Field ◽  
Field Distribution ◽  
Decisive Role ◽  
Local Stress ◽  
Field Measurements ◽  
Tectonic Stress ◽  
In Situ Stress ◽  
Initial Stress Field ◽  
Principal Compressive Stress ◽  
Geological Conditions

At present, due to various reasons, cannot do a large number of field measurements, and the measured results often can only reflect the local stress field distribution. What’s more, the measured results has discreteness, it’s difficult to describe the law of the initial stress field distribution in the entire region. This paper combines topographic and geological conditions and the measured in-situ stress value of Jinping I hydropower station dam area, using FLAC3D4.0, select geological section profile of II1 exploration line for reference, to simulate the incised process of the valley. We get the stress field distribution when rock gravity acting alone, and exert horizontal tectonic stress based on the calculate result of gravity field in the VI terrace model. We inversion the distribution of current Valley stress field, and validate the rationality of the design after compare with the measured data. We obtain the features of stress field of current valley. And we also proved that the regional principal compressive stress plays a decisive role in the formation of the current valley stress field.

Observation of secondary slip systems in tungsten bicrystals

1984 ◽  
Vol 42 ◽  
pp. 478-479
Author(s):  
J. R. Fekete ◽  
R. Gibala
Keyword(s):  
Stress Field ◽  
Grain Boundaries ◽  
Deformation Behavior ◽  
Stress Axis ◽  
Polycrystalline Materials ◽  
Slip Systems ◽  
Metallic Materials ◽  
Twist Boundary ◽  
Secondary Slip ◽  
Plane Normal

The deformation behavior of metallic materials is modified by the presence of grain boundaries. When polycrystalline materials are deformed, additional stresses over and above those externally imposed on the material are induced. These stresses result from the constraint of the grain boundaries on the deformation of incompatible grains. This incompatibility can be elastic or plastic in nature. One of the mechanisms by which these stresses can be relieved is the activation of secondary slip systems. Secondary slip systems have been shown to relieve elastic and plastic compatibility stresses. The deformation of tungsten bicrystals is interesting, due to the elastic isotropy of the material, which implies that the entire compatibility stress field will exist due to plastic incompatibility. The work described here shows TEM observations of the activation of secondary slip in tungsten bicrystals with a [110] twist boundary oriented with the plane normal parallel to the stress axis.

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