Displacement gradient same as strain?

[hoomanya]

Hi, is displacement gradient du/dx same as strain? i though it would be until someone made a comment that they are not the same thing and now I am confused.

 

[Chestermiller]

Hi, is displacement gradient du/dx same as strain? i though it would be until someone made a comment that they are not the same thing and now I am confused.

Displacement gradient is the same as strain. Who made the comment and what was the context?