Talk:Shear stress

message: Shouldn't this be connected to faults and earthquakes? Wetman 20:35, 1 Sep 2004 (UTC)
thread_title: Old comments

message: This forum is trully amazing. It provides a place where people can discuss things, even trivial like shear stress....  —Preceding unsigned comment added by 65.168.235.36 (talk) 23:08, 7 July 2008 (UTC)
thread_title:  This is an interesting forum for scientific discussion 

message: This equation is derived from the flexure formula, and therefore is subject to some of the same assumptions made in its derivation. Namely this formula is only valid for beams made of a homogeneous linear elastic material undergoing only small deflections. Also the edges of the cross section must be parallel to the y-axis, and the shear stresses must be uniform across the cross section width. No triangles or semicircular shapes. Finally the accuracy of this model varies in a rectangular cross section with the height-to-width ratio. The most accurate approximation comes from very narrow beams (height much larger than width).  —Preceding unsigned comment added by 64.126.190.120 (talk) 23:08, 20 October 2008 (UTC)
thread_title:  Important limitations of this formula to be considered. 

message: "This formula is also known as the Jourawski formula."
Jourawho? Never heard of the guy; can't find much to support this (that might not have derived from here).  It's possible that this is a bastardisation of a whole variety of Russian/slavic names
NcLean 58.107.189.35 (talk) 20:22, 12 November 2008 (UTC)
replies: text: I added a ref to it. Wizard191 (talk) 02:57, 13 November 2008 (UTC)
thread_title:  Beam stress formula name 

message: Apart from my feeling that analogies shouldn't be part of the general discription of a phenomenon in the first paragraph, the whole 'hanging something from a wall/ceiling analogy' seems counterintuitive to me. If you hang something on a wall, you usually drive one or multiple screws in there. The resultant forces on the wall are not the same as shear forces. Shear stress is more analogous to rubbing something along a wall, right? For now, I erased these sentences. If someone has a good argument to re-introduce them (either in the first paragraph, or in the body of the article, please do so.
130.89.81.182 (talk) 13:03, 15 May 2009 (UTC)
replies: text: I agree that it's a bad example and therefore should be removed. But just as a note, you should put something in your edit summary, because otherwise it just looks like vandalism. Wizard191 (talk) 14:55, 15 May 2009 (UTC)
thread_title:  "Hanging something" analogy 

message: The article previously basically said "shear stress is parallel to the cross section on which it acts."  Though the writer probably had the concept correct when writing the article, this is mathematically and physically woefully inaccurate.
First, and most importantly, the force creating the shear stress is actually PERPENDICULAR TO THE SURFACE NORMAL of the cross-section on which it acts.  This is because areas aren't defined by a coplanar vector but by a surface normal vector.  This is basically the standard for defining area, probably because, in Euclidean geometry, a vector can point in infinitely many directions and still be coplanar, but there are only two directions perpendicular to a flat plane.
Second, stress is a tensor, not a vector, thus we can't say it's "perpendicular," "parallel," or "tangent" to some face.  However, the components that make up stress, Forces and Areas (stress = force / area) are both scalars associated with unit vectors.  Thus, it is far more correct to use the concepts to describe the differences between "shear" and "normal" components of stress.
So I rewrote the first paragraph to say the following:
"Shear stress is defined as the component of stress coplanar with a given material cross section."
and
"The net force vector which creates this stress is perpendicular to the surface normal vector of the cross section.  Normal stress arises from a net force parallel or antiparallel to the surface normal of a material cross section."
The "normal stress" article might need fixing too; I didn't check.
Jgreeter (talk) 04:14, 16 May 2011 (UTC)
thread_title:  Somewhat Major Edit by [[User:Jgreeter|Jgreeter]] ([[User talk:Jgreeter|talk]]) 04:14, 16 May 2011 (UTC)

message: Somebody was trying to plug in personal research on hypothetical sensors. I deleted it in good faith. --70.183.90.130 (talk) 20:57, 3 July 2012 (UTC)
thread_title: Deleted section on micropillar shear stress sensors

message: Is the statement "...A shear stress, \tau\, is applied..." in the text below the diagram correct? It should read "...A shearing force, F, is applied..." or "normal force vector" or similar. A stress is not applied to anything, rather stress the consequence of some applied force. The tau symbol in the diagram equally needs replacing.  — Preceding unsigned comment added by 194.202.251.141 (talk) 12:51, 25 October 2013 (UTC)
thread_title:  Shear Stress Diagram 

message: Substituted at 05:55, 30 April 2016 (UTC)
thread_title: Assessment comment