Understanding Shearing Strain: Explanation and Examples

[chetzread]

Homework Statement

In the notes , refer to the circled part . It 's stated that the shearing strain is positive when the angle formed by two surfaces oriented along positive y and x axes decreases ..

Homework Equations

The Attempt at a Solution

. As we can see from the figure( paralleogram ) , one of the angle increases , while another angle decreases , am i right ? Why the author said angle decreases ?

 

[chetzread]

Here it is

 

[chetzread]

is the notes wrong
?

 

[Tom.G]

...angle formed by two surfaces oriented along positive y and x axes decreases ..

I think that could be stated more clearly. Obviously there are two surfaces oriented along each axis. To match the description to the diagram, try rewording it to:

"...angle formed by two surfaces closest to the origin and oriented along positive y and x axes decreases .."

 

[chetzread]

closest to the origin

what do you mean by it ? Can you explain further ?

 

[Tom.G]

"...closest to the origin..."

what do you mean by it ? Can you explain further ?

closest to the origin of the graph as shown in the image of your post #2.
-or-
the two faces closest to and facing the X-Z and Y-Z planes.
https://www.physicsforums.com/attachments/img_20161015_102808-jpg.107454/

 

[chetzread]

"...closest to the origin..."

closest to the origin of the graph as shown in the image of your post #2.
-or-
the two faces closest to and facing the X-Z and Y-Z planes.
https://www.physicsforums.com/attachments/img_20161015_102808-jpg.107454/

if the downwrads plane is sheared to the right , and the upper planes sheared to the left , then the angle formed by two surfaces closest to the origin and oriented along positive y and x axes will increase , right ?.

 

[Tom.G]

Right!