How can i solve the stress tensor to find principal stresses?

For example, here is stress tensor matrix as [a b c; d e f; g h e] . I want to find principal stresses from this matrix.

[Daniel M]

Aren't they just the elements of the main diagonal?

[David Goodmanson]

Hi btulu,

you can find the principal stresses by means of the eigenvalue decomposition of the stress tensor matrix.