it is define stress component with fea calculation... https://www.youtube.com/watch?v=D0hafp3t7Q4

1. Strength of Material
With FEA
In SolidWork & ANSYS ;Catia; Stadd; PTC

2. Stress

3. But In 3D

4. Stress Component

5. Beam Modeling

6. Stress component

7. Stress component

8. Stress component
Principal stress is the
maximum normal stress a
body can have at its some
point. It represents purely
normal stress. If at some
pointprincipal stress is said
to have acted it does not have
any shear stresscomponent.

9. Stress Component