Enter the stress in the x-direction, the stress in the y-direction, and shear stress into the calculator to determine the principal stresses.

Principal Stress Formula

The following formula i used to calculate the two principal stresses.

  • Where σ1,2 are the principal stresses
  • σx is the stress in the x-direction
  • σy is the stress in the y-direction
  • τ is the shear stress

Principal Stress Definition

Principal stress is defined as the maximum and minimum total stresses acting on an object at any given point.

Principal Stress Example

How to calculate a principal stress?

  1. First, determine the normal stress.

    Calculate the normal stress in the x and y directions along the plane of action.

  2. Next, determine the shear stress.

    Calculate the shear stress in the x-y plane.

  3. Finally, calculate the principal stresses.

    Calculate the principal stress (max and min) using the equation above.


What is a principal stress?

A principal stress is defined as the normal stress calculated at an angle where the shear stress in the plane is 0.