1. Ratings#
1.1. Generalities#
\(\sigma\) refers to the effective stress tensor in small disturbances, noted in the form of the following vector:
\((\begin{array}{}{\sigma }_{11}\\ {\sigma }_{22}\\ {\sigma }_{33}\\ \sqrt{2}{\sigma }_{12}\\ \sqrt{2}{\sigma }_{13}\\ \sqrt{2}{\sigma }_{23}\end{array})\)
We note: