Material2D

All 2D material models support the following basic output types.

variable label	physical meaning
S11	$\sigma_{11}$
S12	$\sigma_{12}$
S22	$\sigma_{22}$
E11	$\varepsilon_{11}$
E12	$\varepsilon_{12}$
E22	$\varepsilon_{22}$
SP	all principal stress components
EP	all principal strain components

Depending on the specific material model, additional output types may be available.

The history vector is a vector of variadic length that stores the necessary history variables for the material model. Different material models may have different history variable storage layout.