
[Sponsors] 
December 22, 2008, 04:57 
shear stress

#1 
Guest
Posts: n/a

Good day!
Would you be so kind helps me understand physical meaning of "shear stress", and "shear strain?" Mihail 

December 22, 2008, 06:00 
Re: shear stress

#2 
Guest
Posts: n/a

A shear stress, denoted (tau), is defined as a stress which is applied parallel or tangential to a face of a material, as opposed to a normal stress which is applied perpendicularly. In other words, considering that weight is a force, hanging something from a wall creates a shear stress on the wall, since the weight of the object is acting parallel to the wall, as opposed to hanging something from the ceiling which creates a normal stress on the ceiling, since the weight is acting perpendicular to the ceiling.
Shear strain is a strain that acts parallel to the surface of a material that it is acting on. Normal strain, in contrast, acts perpendicular to the surface. There are two ways to interpret shear strain: the average shear strain and the engineering shear strain. The variable used to denote average shear strain is while denotes engineering shear strain. Consider an infinitesimal rectangle in the xy plane subject to shear strain. The rectangle becomes a parallelogram where is the displacement from the y axis in the x direction and is the displacement from the x axis in the y direction. The average shear strain is [edit] Definition of engineering shear strain where is the angle before deformation and is the angle at that same point after deformation. Therefore describes the total deformation. 

December 22, 2008, 06:50 
Re: shear stress

#3 
Guest
Posts: n/a

Dear Charles!
Thank you for so perfect explanation! Maybe you can tell me meaning of "shear flow" and "shear layer". Mihail. 

December 22, 2008, 20:18 
Re: shear stress

#4 
Guest
Posts: n/a

Shear flow is:
in a solid body, the gradient of a shear stress force through the body; in a fluid, it is the flow induced by such a force gradient  see Viscosity for a fuller treatment. Shearing layers is a concept coined by architect Frank Duffy which was later elaborated by Stewart Brand in his book How Buildings Learn: What Happens After They're Built (Brand, 1994), and refers to buildings as composed of several layers of change. 

December 23, 2008, 01:27 
Re: shear stress

#5 
Guest
Posts: n/a

thanks a lot!
Merry Christmas and a happy new year! 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Shear Stress Calculation in the flow.  auburnuser  FLOW3D  10  February 2, 2015 11:35 
Fluid wall shear stress  Sinead Kelly (Kelly)  OpenFOAM Running, Solving & CFD  2  March 30, 2011 06:41 
How to get shear stress all over the flow domain  lingo  FLUENT  2  November 3, 2003 22:16 
shear stress scalar definitions?  Novak Elliott  CFX  0  April 6, 2003 01:45 
What is the detail definition of wall shear stress  zjm  FLUENT  0  January 2, 2002 08:43 