shear stress

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Related to shear stress: Shear strain, Normal stress

shear stress

the force acting in shear flow expressed per unit area; units in the CGS system: dynes/cm2.

shear stress

A frictional force tangential to the direction of a flowing fluid, the force of which is directly related to the fluid’s viscosity shear stress. In blood vessels, shear stress acts on endothelium and is the mechanical force responsible for the acute changes in luminal diameter. 

Stress parallel to a given surface (e.g., a fault plane) that results from forces applied parallel to the surface or from remote forces transmitted through surrounding rock.


(stres) [Fr. estresse, narrowness]
1. Any physical, physiological, or psychological force that disturbs equilibrium
2. The consequences of forces that disturb equilibrium.
3. Force applied per unit area. In the physical sciences, stresses include forces that deform or damage materials, such as impact, shear, torsion, compression, and tension. These physical stresses are particularly important in certain branches of health care, e.g., dentistry or orthopedic surgery, and in biotechnology industries, e.g., in the design and use of prostheses, grafts, and perfusion pumps.

Physiological stresses include agents that upset homeostasis, such as infection, injury, disease, internal organ pressures, or psychic strain.

In psychology, stresses include perceptions, emotions, anxieties, and interpersonal, social, or economic events that are considered threatening to one's physical health, personal safety, or well-being. Marital discord; conflicts with others; battle, torture, or abuse; bankruptcy; incarceration; health care crises; and self-doubt are all examples of conditions that increase psychic stresses. The response of an organism or material to stress is known as adaptation. See: adaptation; anxiety; fracture; homeostasis; Laplace, law of; relaxation response

critical incident stress

One's emotional reaction to a catastrophic event such as a mass casualty incident or the death of a patient or coworker. Often such events negatively affect the well-being of health care providers.

oxidative stress

The cellular damage caused by oxygen-derived free radical formation. The three most important are superoxide (O2-), hydrogen peroxide (H2O2), and hydroxyl ions; these are produced during normal metabolic processes as well as in reaction to cell injury. The extent of their damaging potential can be decreased by antioxidants.
See: antioxidant; free radical; superoxide; superoxide dismutase

prenatal stress

Anxiety, tension, depression, or other psychological discomfort experienced by a pregnant woman.

shear stress



1. to remove the fleece of a sheep.
2. pressure on a mass in such a way that planes within it are pressured to move in a direction parallel to the pressure. Any movement is proportional to the distance from the plane at which movement occurs.

shear injury
injury to tissues caused by shear pressure. See shearing injuries (2).
shear stress
the stress to which a tissue is subjected by a shear force without injury actually occurring.
References in periodicals archive ?
Areas with low Reynolds shear stress have a promising appearance to attract some fish species.
Given a pressure drop, [DELTA]P, measured across a capillary length L, the apparent shear stress is:
2) The maximum interface shear stress in bone at the medial coating / bone interface to be less than the maximum interface shear stress using uncoated Ti stem.
The pressure gradient and shear stress show an increase for slight increase in strength of magnetic field and then decrease for further increase in magnetic field which shows that magnetic field can be used to control the blood flow of hypertensive patients.
To determine whether relationships existed between interface shear stress and horizontal stiffness of cushions, we calculated Pearson product moment correlation coefficients (a = 0.
Referring back to the extrudate in Figure 6, predictions of wall shear stress show that it is below the 140 kPa critical stress at 117 kPa, and indeed no sharkskin is evident.
The structure of a gel, for example, will start to break down once a particular shear stress is exceeded, and the material will then become more fluid.
Surgeons and researchers can view the movie and see detailed information about blood pressure, shear stress, and other conditions at each point in the blood vessels.
In each cutting plane, an equivalent stress amplitude by a linear combination of the normal stress amplitude and the shear stress amplitude is calculated (cf.