Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Normal stress


Related Topics

In the News (Thu 18 Apr 19)

  
  Stress (physics) - Wikipedia, the free encyclopedia
Stress strain diagrams are usually presented as engineering stress, even though the sample may undergo a substantial change in cross-sectional area during testing.
Being a vector, the stress has two components, one in the plane of the area, A, the shear stress, and one perpendicular, the normal stress.
Plot the state of stress on the x-plane as the point A whose abscissa is the magnitude of the normal stress (tension is positive), and whose ordinate is the shear stress (counter-clockwise shear is negative).
en.wikipedia.org /wiki/Stress_(physics)   (1819 words)

  
 Analysis of Stress
Mathematically, the state of stress at a point in an elastic body is determined by six independent stress components and is specified by a second-order symmetric Cartesian tensor, also known as the stress tensor.
You assume the sign of a stress component is positive when its direction and the normal vector of the surface, on which the component of the stress tensor is acting, are of the same sign.
This is a vector representation of the symmetric stress tensor.
documents.wolfram.com /applications/structural/AnalysisofStress.html   (2251 words)

  
 StressMohr Program
We choose the normal to point into the body and the stress vector is the force per unit area acting onto the plane from the outside of the body.
be the angle between the normal and the stress vector as shown in the sketch.
For lithostatic stress the magnitude of the stress is independent of the orientation of the plane, the stress is always perpendicular to the plane, and the shear component is always zero.
www.geo.lsa.umich.edu /~vdpluijm/stressmohr/stressmohr.html   (4386 words)

  
 Manage Stress   (Site not responding. Last check: 2007-10-14)
Stress is an adaptive response that has developed in all animals to help them respond to threatening situations and other stressors.
Because of this stress response, you are ready to either flee from or to battle with the bear.
Unfortunately, when our stress response is sustained for long periods of time, perhaps due to a demanding boss or work schedule, then the stress response may be less adaptive and eventually lead to health problems.
www.bragg.army.mil /528csc/StressPoint1.htm   (893 words)

  
 Stress
The component parallel to the plane is the shear stress; component perpendicular is the normal stress.
Maximum shear stress is on two planes at 45° to the principal stresses, called the conjugate planes of maximum shear stress.
With increased stress, failure occurs at a stress that is called the 'strength' of the material.
courses.eas.ualberta.ca /eas421/stress.html   (1738 words)

  
 Normal Stress Effects in Cartilage   (Site not responding. Last check: 2007-10-14)
We are studying the nonlinear behavior of cartilage, in particular normal stresses that are not predicted by small strain theory. 
One of the possible mechanisms which may contribute to the normal stress effect is the nonlinear elasticity of the solid matrix.
Finite torsion theory predicts a normal stress effect during constrained torsion of an elastic solid.         
www.duke.edu /~mal6/nf.html   (73 words)

  
 Stress   (Site not responding. Last check: 2007-10-14)
Stressful events may cause men and women who have relatively low levels of the neurotransmitter serotonin (and therefore a higher risk for depression or anger) to produce more of certain immune system proteins (called cytokines), which in high amounts cause inflammation and damage to cells, including possibly heart cells.
Stress may cause physiologic alterations, such as increased adrenal hormone levels or resistance in the arteries, that may interfere with normal blood flow to the placenta.
Stress builds up, but the worker has the illusion, even subconsciously, that the stress itself is providing safety or preparedness, so does nothing to correct the condition.
www.summitcountyinternist.com /id219.htm   (7121 words)

  
 3D Stress Modelling - SMC Research
Normal stress is high (red) on shallow surfaces perpendicular to gravity and low on the steeply dipping tops of the faults, indicating where faults are likely to dilate in extension.
In this case, the highest normal stresses are to be found, as expected, on the steeply dipping areas of the fault perpendicular to the major principal stress orientation.
It is envisaged that simple stress analysis such as this can be incorporated into 3D modelling of fault sealing and fluid flow in order to refine the mathematical prediction of clay/shale smear development in fault zones.
www.bdrg.esci.keele.ac.uk /smcresearch1.htm   (387 words)

  
 Measurements of Normal Stress Differences in Polymer Melts at High Shear Rates   (Site not responding. Last check: 2007-10-14)
First normal stress difference, N1, is presently measured using a cone/plate rheometer, however, this only provides measurements to a maximum shear rate of 10 sec^-1 due to edge fracture of the melt and other flow instabilities.
Regarding the measurement of the second normal stress difference, N2, a survey of the literature has shown that there is only a modest amount of experimental work on this topic.
The origin of measuring normal stress differences with the pressure hole method is what was described as "the hole pressure error" by Broadbent et al.
www.iprod.auc.dk /forsk/poly/proj/erik.htm   (1155 words)

  
 eMedicine - Stress Fracture : Article by Partha Sinha, MBBS, MTech, DRM   (Site not responding. Last check: 2007-10-14)
Stress fractures of the pubis also are common in long-distance runners, as is distal fibula involvement.
Stress fractures are less common in the upper extremity and the axial skeleton.
Typically, the stress fracture appears as a low-signal band that arises from the cortex of the bone and extends perpendicular to the surface of the bone (see Images 2-3).
www.emedicine.com /radio/topic783.htm   (3093 words)

  
 CT Detects Atherosclerosis in Patients With Normal Stress Test Results   (Site not responding. Last check: 2007-10-14)
A stress test involves the measurement of heart rate and blood pressure before, during and after a patient exercises on a treadmill.
In an imaging stress test, such as myocardial perfusion single-photon emission CT, a radioactive tracer accumulates in the heart according to blood flow, emitting signals that a special type of camera captures to reveal areas of the heart not getting enough blood flow.
Among the 1,119 patients who had normal stress imaging tests, 56 percent had calcium scores on CT greater than 100, and 31 percent of patients had scores greater than 400.
www.asrt.org /content/news/IndustryNewsBriefs/CT/CTDetectsA040824.aspx   (544 words)

  
 Cartilage Normal Stress and Equilibrium Friction Coefficient   (Site not responding. Last check: 2007-10-14)
The normal stress effect and equilibrium friction coefficient of articular cartilage under steady frictional shear
The two parameters measured are the normal force and frictional torque, from which the friction coefficient was then calculated.
The normal stress effect has not been previously reported for articular cartilage, and represents an intriguing mechanical response not commonly encountered in solids, though common in non-Newtonian fluids.
www.columbia.edu /~ga29/ab_normal_stress.html   (220 words)

  
 The stress tensor   (Site not responding. Last check: 2007-10-14)
When a fluid is at rest, only normal stresses are exerted, the normal stress is independent of the direction of the normal to the surface element across which it acts, and the stress tensor has the form
Such a quantity is provided by (negative) the average of the three normal stresses for any orthogonal set of axes.
is the viscous stress tensor and has the distinctive property of begin entirely due to the existence of the motion of the fluid.
astron.berkeley.edu /~jrg/ay202/node69.html   (423 words)

  
 Stress   (Site not responding. Last check: 2007-10-14)
Studies suggest that the inability to adapt to stress is associated with the onset of depression or anxiety.
Some evidence suggests that repeated release of stress hormone produces hyperactivity in the hypothalamus-pituitary-adrenal axis and disrupts normal levels of serotonin, the nerve chemical that is critical for feelings of well-being.
The contradictory effects of stress on the immune system can have mixed effects on autoimmune diseases (which are those that are caused by inflammation and damage from immune attacks on the body).
www.reutershealth.com /wellconnected/doc31.html   (8259 words)

  
 Re: Shear and normal stress on a boundary
Re: Shear and normal stress on a boundary
In Response To: Shear and normal stress on a boundary (Fing)
Shear and normal stress on a boundary - Fing, Wed, 19 May 2004, 1:15 p.m.
www.cfd-online.com /Forum/cfx_archive.cgi?read=7725   (100 words)

  
 Normal and Shear Stress
The normal and shear stresses are the components of the traction,
The equations for normal and shear stress are commonly referred to as the fundamental stress equations.
Assuming static equilibrium and using the relationships illustrated in Figure 15, derivation of the fundamental equation for normal stress begins with the balancing of forces where:
www.geology.sdsu.edu /visualstructure/vss/htm_hlp/ns_ste.htm   (259 words)

  
 Holistic Health Encyclopedia - S   (Site not responding. Last check: 2007-10-14)
Normally chyme can remain in the small intestine 3-10 hours (irritants in our food and foods to which we are allergic can initiate a “peristaltic rush” which can empty the entire small intestine in a few minutes, leading to poor food absorption and often diarrhea).
There are 24 spinal vertebrae (normally 7 cervical vertebrae in the neck, 12 dorsal or thoracic vertebrae in the upper and mid back, and 5 lumbar vertebrae in the lower back) in addition to the partly fused bones of the sacrum and coccyx.
Epidermis varies in thickness throughout the body depending mainly on frictional forces and is thickest on the palms of the hands and soles of the feet.
www.myholistic.com /glossary/S.php3   (8360 words)

  
 Strength of Materials: Normal and Shear Stress Distribution
This worksheet can be used to calculate the normal and shear stress distribution for the cross section of a rectangular beam.
The bending moment and shear stress at a point on a rectangular beam are M and V, respectively.
Calculate the normal and shear stress at a number, n, of points along the center line of the beam cross section.
www.mathcad.com /library/LibraryContent/MathML/stress.htm   (221 words)

  
 NEGATIVE NORMAL STRESS,
NEGATIVE NORMAL STRESS, discovered by physicists a quarter-century ago, is a poorly understood attraction between two parallel plates that occurs when certain complex fluids flow between them.
In addition to the tangential stress, they react with a positive normal stress--a force that acts perpendicular to the plates.
The striking difference between these two systems is that one is a fairly dilute suspension of nanofibers while the second is a concentrated suspension of soft spheres, and yet they show the same response, suggesting some underlying universal phenomenon which is now being further investigated.
newton.ex.ac.uk /aip/glimpse.txt/physnews.674.2.html   (443 words)

  
 Photo Glossary of Earthquakes
It is the stress component perpendicular to a given surface, such as a fault plane, that results from forces applied perpendicular to the surface or from remote forces transmitted through the surrounding rock.
Tensional stress is the stress that tends to pull something apart.
Shear stress is the stress component parallel to a given surface, such as a fault plane, that results from forces applied parallel to the surface or from remote forces transmitted through the surrounding rock.
earthquake.usgs.gov /image_glossary/stress.html   (223 words)

  
 Normal stress measurement via image analysis of interfacial deformation   (Site not responding. Last check: 2007-10-14)
In the case of a steady rotating liquid bridge, the deformation of the interface is strictly due to normal stress swelling effects.
The shape of the interface and the jump in normal stress across the interface are determined using pressure-stress image analysis (P-SIA) from high resolution digital images.
The polystyrene solution exhibits a normal stress at the interface which grows with the square of the rotation rate.
flux.aps.org /meetings/YR00/DFD00/abs/S1020001.html   (210 words)

  
 MAPPING THE COEFFICIENT OF FRICTION OF THE SERPENTINE MINERAL CHRYSOTILE RELATIVE TO EFFECTIVE NORMAL STRESS AND ...   (Site not responding. Last check: 2007-10-14)
We report new frictional strength data for the serpentine mineral chrysotile at effective normal stresses between 40 and 200 MPa in the temperature range 25-280°C. Triaxial friction experiments were performed using a 1-mm-thick layer of chrysotile gouge placed along a sawcut surface in antigorite driving blocks.
Overall, the coefficient of friction of water-saturated chrysotile gouge increases both with increasing temperature and effective normal stress, but the temperature-related increases begin at about 100°C. For heated chrysotile, the rate of increase in coefficient of friction with increasing effective normal stress is 3-4 times higher below 100 MPa than above.
As a result, a minimum in the coefficient of friction (<0.1) occurs at normal stresses below 50 MPa at about 100°C. Maximum coefficient of friction (>0.55) results from a combination of effective normal stresses >150 MPa and temperatures >250°C. The low-strength region is characterized by velocity-strengthening and the high-strength region by velocity-weakening behavior.
gsa.confex.com /gsa/2002AM/finalprogram/abstract_41162.htm   (486 words)

  
 Normal Stress Blood Pressure
The problem with this is that people do not live completely stress free lives.
As a result I was diagnosed as having "white coat stress syndrome", but I am still on the bp meds.
Granted it will rise during exercise and this is normal but otherwise it is not normal to have elevated blood pressure.
www.medhelp.org /forums/cardio/messages/31044a.html   (1368 words)

  
 Urocortin-Deficient Mice Display Normal Stress-Induced Anxiety Behavior and Autonomic Control but an Impaired Acoustic ...
Normal stress-induced autonomic and endocrine responses in Ucn
Impaired stress response and reduced anxiety in mice lacking a functional corticotropin-releasing hormone receptor I. Nat.
Urocortin expression in the Edinger-Westphal nucleus is up-regulated by stress and corticotropin-releasing hormone deficiency.
mcb.asm.org /cgi/content/full/22/18/6605   (4087 words)

  
 Normal Stress
NORMAL STRESS is the intensity of the net forces acting normal (perpendicular) to an infinitely small area dA within an object per unit area.
If the normal stress acting on dA pulls on it, then it is referred to as tensile stress, whereas if it pushes on the area, it is called compressive stress.
An average normal stress at any point on the cross sectional area can be calculated as follows:
gnatchung.tripod.com /Mechanics/id3.html   (71 words)

  
 MedlinePlus Medical Encyclopedia: Cortisol - urine
The test involves only normal urination, and there is no discomfort.
The normal range is 10 to 100 mcg/24 h.
Normal value ranges may vary slightly among different laboratories.
www.nlm.nih.gov /medlineplus/ency/article/003703.htm   (653 words)

  
 Health Education: Stress, Depression, Anxiety, Drug Use
Stress is when you are worried about getting laid off your job, or worried about having enough money to pay your bills, or worried about your mother when the doctor says she may need an operation.
Allergy is a definite stress, requiring large changes in energy expenditure on the part of your body's defense system to fight off what the body perceives as a dangerous attack by an outside toxin.
Carrying too heavy a stress load is like running your car engine past the red line; or leaving your toaster stuck in the "on" position; or running a nuclear reactor past maximum permissible power.
www.teachhealth.com   (1976 words)

  
 All about Stress at Medical-Information.Org
Stress is defined as a nonspecific response of the body to any demand made upon it which results in symptoms such as rise in the blood pressure, release of hormones, quickness of breathe, tightening of muscles, perspiration, and increased cardiac activity.
Some stress keeps us motivated and alert, while too little stress can create problems.
However, too much stress can trigger problems with mental and physical health, particularly over a prolonged period of time.
Stress.Medical-Information.org   (85 words)

  
 Session BH - Non-Newtonian Fluids.
First normal stress differences in shear flow are a fundamental property of Non-Newtonian fluids.
Experiments involving dilute suspensions of slender fibers exhibit a sharp transition to non-zero normal stress differences beyond a critical shear rate, but existing continuum theories for rigid rods predict neither this transition nor the corresponding magnitude of this effect.
In the non-Newtonian case, normal stresses result in a thickening of the film, in accordance with experimental observations.
flux.aps.org /meetings/YR00/DFD00/abs/S220.html   (1199 words)

  
 Effects of normal stress variation on the strength and stability of creeping faults
A central problem in studies of fault interaction and earthquake triggering is that of quantifying changes in frictional strength and the constitutive response caused by dynamic stressing.
We imposed normal stress vibrations on creeping laboratory shear zones to investigate the process of dynamic weakening and the conditions under which resonant frictional behavior occurs.
Citation: Boettcher, M., and C. Marone (2004), Effects of normal stress variation on the strength and stability of creeping faults, J.
www.agu.org /pubs/crossref/2004/2003JB002824.shtml   (377 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.