Mohr's Circle and Failure Criterion for Planar Stress States

Mohr's circle

state of stresses

σ

x

σ

z

τ

angle

deg

material properties

type of material

ductile

brittle

σ

y

σ

UT

σ

UC

principal stresses

σ 1	4.835	σ 3	-2.335
τ max	3.585	θ	19.95

selected stresses

σ A	0	σ C	0
τ R	0

von Mises stress

σ

A

6.334

N

f

0.7894

maximum normal stress criterion

N

f

0

Mohr's circle

This Demonstration calculates the principal stresses and direction angle for a differential element and shows the following:

• the stresses for a selected angle of rotation, including the von Mises stress

• the element and its associated angles

• the corresponding Mohr's circle

• the safety factor of the element when material properties are introduced

• the "safety zone" for ductile and brittle materials