Propagation of a Sudden Rotary Disturbance in an Elastic Plate in Plane Stress

1956 ◽  
Vol 23 (2) ◽  
pp. 284-286
Author(s):  
J. N. Goodier ◽  
W. E. Jahsman
Keyword(s):  
Shear Stress ◽  
Radial Velocity ◽  
Plane Stress ◽  
Elastic Plate ◽  
Uniform Shear ◽  
Subsequent Motion

Abstract Detailed results are found for two plane-stress problems of an elastic plate with a hole from which a symmetrical disturbance is propagated. In the first a uniform shear stress is suddenly applied and maintained at the hole. In the second a uniform (rotary) velocity is suddenly applied and maintained. The subsequent motion is entirely rotary and involves shear stress only. The problems are mathematically analogous to those of symmetrical pressure and radial velocity at the hole, already solved by Kromm, and his analysis is followed. The existence of a similar analogy in the statical cases is well known.

scholarly journals Branching exponent heterogeneity and wall shear stress distribution in vascular trees

2001 ◽  
Vol 280 (3) ◽  
pp. H1256-H1263 ◽  
Author(s):  
Kelly L. Karau ◽  
Gary S. Krenz ◽  
Christopher A. Dawson
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Coefficient Of Variation ◽  
Vessel Diameter ◽  
Mean Value ◽  
Heterogeneous Distribution ◽  
Uniform Shear ◽  
The Mean ◽  
Wall Shear ◽  
Stress Dependent

A bifurcating arterial system with Poiseuille flow can function at minimum cost and with uniform wall shear stress if the branching exponent ( z) = 3 [where z is defined by ( D 1) z = ( D 2) z + ( D 3) z ; D 1 is the parent vessel diameter and D 2 and D 3 are the two daughter vessel diameters at a bifurcation]. Because wall shear stress is a physiologically transducible force, shear stress-dependent control over vessel diameter would appear to provide a means for preserving this optimal structure through maintenance of uniform shear stress. A mean z of 3 has been considered confirmation of such a control mechanism. The objective of the present study was to evaluate the consequences of a heterogeneous distribution of z values about the mean with regard to this uniform shear stress hypothesis. Simulations were carried out on model structures otherwise conforming to the criteria consistent with uniform shear stress when z = 3 but with varying distributions of z. The result was that when there was significant heterogeneity in z approaching that found in a real arterial tree, the coefficient of variation in shear stress was comparable to the coefficient of variation in z and nearly independent of the mean value of z. A systematic increase in mean shear stress with decreasing vessel diameter was one component of the variation in shear stress even when the mean z = 3. The conclusion is that the influence of shear stress in determining vessel diameters is not, per se, manifested in a mean value of z. In a vascular tree having a heterogeneous distribution in zvalues, a particular mean value of z (e.g., z = 3) apparently has little bearing on the uniform shear stress hypothesis.

An Evaluation of a Modified Iosipescu Specimen for Measurement of Elastic-Plastic Properties of Solder Materials

2010 ◽  
Author(s):  
Subhasis Mukherjee ◽  
Abhijit Dasgupta
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Solder Joint ◽  
Scale Effects ◽  
Element Model ◽  
Test Material ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Uniform Shear ◽  
Shear Stress Field

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.

VEGFR2 signalling contributes to increased endothelial susceptibility to TNF-α under chronic non-uniform shear stress

2011 ◽  
Vol 219 (2) ◽  
pp. 499-509 ◽  
Author(s):  
Katharina Urschel ◽  
Christoph D. Garlichs ◽  
Werner G. Daniel ◽  
Iwona Cicha
Keyword(s):  
Shear Stress ◽  
Uniform Shear ◽  
Tnf Α

scholarly journals Relaxation methods applied to engineering problems. X. The graphical representation of stress

1944 ◽  
Vol 183 (993) ◽  
pp. 125-134 ◽  
Keyword(s):  
Shear Stress ◽  
Plane Stress ◽  
Graphical Representation ◽  
Special Problem ◽  
Relaxation Methods ◽  
Engineering Problems ◽  
Vector Quantity

A convenient representation of a vector quantity (e.g. the shear stress on a specified plane) is by contours which exhibit its resultant magnitude and by ‘trajectories’ which have its direction at every point. But it sometimes happens that only its components in two perpendicular directions are known, and then, while the contours are easy to construct, derivation of the ‘trajectories’ presents a special problem. If this can be solved, tensor quantities also will be representable, e.g. a state of plane stress. By orthodox methods the problem would appear to be difficult, but in this paper it is shown to yield to ‘relaxational’ attack.

scholarly journals Wind effects on retention time in highway ponds

2008 ◽  
Vol 57 (11) ◽  
pp. 1713-1720 ◽  
Author(s):  
T. R. Bentzen ◽  
T. Larsen ◽  
M. R. Rasmussen
Keyword(s):  
Shear Stress ◽  
Retention Time ◽  
Numerical Study ◽  
Dominant Role ◽  
Road Runoff ◽  
Detention Ponds ◽  
Uniform Shear ◽  
General Investigation

The paper presents results from an experimental and numerical study of wind-induced flows and transportation patterns in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress with the situation of a “real” spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non-uniform wind field distributions are not significant to this study.

Flow of Greases Under the Action of Complex Shear

1968 ◽  
Vol 90 (3) ◽  
pp. 604-607 ◽  
Author(s):  
G. V. Vinogradov ◽  
A. A. Mamakov
Keyword(s):  
Shear Stress ◽  
Axial Direction ◽  
Coaxial Cylinder ◽  
Great Decrease ◽  
Annular Space ◽  
Uniform Shear ◽  
Complex Shear ◽  
Shear Stress Field ◽  
Limiting Value ◽  
Cylinder Viscometer

Experiments were performed in a coaxial cylinder viscometer in which there were realized separately and simultaneously flows of grease and bright stock (Newtonian fluid) in the axial and peripheral direction. The latter was at uniform shear stress field. The effect of peripheral on axial-flows was a great decrease in resistance toward deformation in the axial direction. This is a very important peculiarity of greases, which are non-Newtonian media, when considering their flow in labyrinth boxes and some other devices. The effect of axial on peripheral flow showed somewhat increased resistance toward the latter. Such behavior was attributed to continuous inflow of fresh grease into the annular space where it did not remain long enough for structural destruction to reach a limiting value.

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