# MOHR’S STRESS CIRCLE CLASS NOTES FOR MECHANICAL ENGINEERING

## ENGINEERING

### stresses and strains. Mohr’s circle is a graphical transformation of two dimensional plane stresses. It is extremely simple and useful.

#### Angle NPR will be 2θpp2.

It is angle between the given plane AB and the other principal plane PR.

#### There are three planes, major principal plane, intermediate principal plane and minor principal plane. ##### Fig. ELEMENTS OF MOHR’S STRESS CIRCLE ##### Fig. 3- DIMENSIONAL STRESS SYSTEM

THREE- DIMENSIONAL STRESS SYSTEM

3 Mohr’s Stress Circles (Circle 1, Circle 2 and Circle 3)

Zero shear stress on principal planes

There is normal stress on the plane of maximum shear

 Sr. NO. Principal Planes Principal stresses Shear stress on principal planes 1. C1A,  C1C OA=σ1, OC=σ3 Zero 2. C2A, C2B OA=σ1, OB=σ2 Zero 3. C3B, C3C OB=σ2, OC=σ3 Zero

 Sr. No. Planes of maximum shear Maximum shear stress Normal stress on the plane of maximum shear 1. C1D, C1G C1D=C1G=(σ1-σ3)/2 OC1=(σ1-σ3)/2 2. C2E, C2H C3F= C3I=  (σ1-σ2)/2 OC2=(σ1-σ2)/2 3. C3F, C3I C1D=C1G=(σ2-σ3)/2 OC3=(σ2-σ3)/2