strain in voigt notation
- Strain tensor can be transformed into$$\tag{1} \mathbf{\varepsilon} = \left[ \begin{array}{c} \varepsilon_{xx} \newline \varepsilon_{yy} \newline \varepsilon_{zz} \newline 2 \varepsilon_{xy} \newline 2 \varepsilon_{yz} \newline 2\varepsilon_{zx} \end{array} \right], $$that is an expression of symmetric tensor in lower order tensor.
Rhys Geoffrey Povey, "Voigt transforms", rhyspovey, 22 Jul 2024 (), url https://rhyspovey.com/science/voigt.pdf [20250131].