Mohr's Circle
Using
the normal and shear stresses of a system, Mohr's
Circle can be constructed. It is a very useful and
visual diagram in rock mechanics (and the field of
mechanics in general).
In
the figure below, the min and max principle
stresses are denoted by red
font and the max shearing stress is denoted by the
orange font. The
average normal stress is at the center of the
circle, along the normal stress axis. The maximum
shearing stress is equal to the radius of the
circle, and the min and max normal stresses can be
found by subtracting and adding the average normal
stress to the radius, respectively.