post_calcul unknown operat ...

This records activates calculation post results. Here unknown can be one of the matrices -materi_stress, -materi_strain_elasti, -materi_strain_plasti, -materi_strain_total or unknown can be one of the vectors -materi_velocity, -materi_displacement, or unknown can be one of the scalars -condif_temperature, -groundflow_pressure.

The results of these calculations are stored for each node_dof record in a node_dof_calcul record, and are stored for each post_point_dof record in a post_point_dof_calcul record, and are stored for each post_line_dof record in a post_line_dof_calcul record, and are stored for each post_quadrilateral_dof record in a post_quadrilateral_dof_calcul record.

We denote a matrix unknown with $A_{ij}$ and denote a vector unknown with $A_i$, and denote a scalar unknown with $a$.

If operat is -prival then three principal values of a matrix $A_{ij}$ are calculated. Each principal value contains the size of the principal vector. The principal values are ordered (the first value is the largest one, and the last value is the smallest one).

If operat is -privec then three principal vectors of a matrix $A_{ij}$ are calculated. Each principal vector contains the $x$, $y$ and $z$ component of the principal vector. The same ordering as used for -prival is used here also.

If operat is -average then $\frac{1}{3} ( A_{11} + A_{22} + A_{33} )$ is calculated for a matrix or $\frac{1}{3} ( A_1 + A_2 + A_3 )$ is calculated for a vector.

If operat is -absol then the absolute value of a scalar $a$ is calculated.

If operat is -positive then the average of the positive principal values for a matrix is calculated. If materi_strain_plasti is taken for the matrix $A_{ij}$, then this operator typically can be used as a measure for the amount of tensile failure (cracking).

If operat is -negative then the average of the negative principal values for a matrix is calculated. If materi_strain_plasti is taken for the matrix $A_{ij}$, then this operator typically can be used as a measure for the amount of compression failure (crunching).

If operat is -sizetot then $\sqrt { 0.5 A_{ij} A_{ij} }$ is calculated for a matrix or $\sqrt { 0.5 A_i A_i }$ is calculated for a vector. This measures the size of a matrix or the size of a vector.

If operat is -sizedev then $\sqrt { 0.5 B_{ij} B_{ij} }$ is calculated where $B_{ij}$ is the deviatoric part of a matrix $A_{ij}$: $B_{ij} = A_{ij} - \delta_{ij} \frac{A_{11}+A_{22}+A_{33}}{3}$ where $\delta_{ij}$ is 1 if $i=j$ and is 0 otherwise. This measures the size of the deviatoric part of the matrix.

Specially for geotechnics you can set operat to -phimob in case unknown is -materi_stress. Then the 'mobilised friction angle' is calculated in degrees. It is default calculated without taking cohesion into account.

Specially for geotechnics you can set operat to -total in case unknown is -materi_stress. Then the total stress is calculated from the effective stress and the groundflow total pressure.

Specially for geotechnics you can set operat to -static in case unknown is -groundflow_pressure. Then the static pressure is calculated.

Specially for geotechnics you can set operat to -dynamic in case unknown is -groundflow_pressure. Then the dynamic pressure is calculated.

Specially for geotechnics you can set operat to -total in case unknown is -groundflow_pressure. Then the total pressure is calculated.

The next piece of input file

...
materi_stress
materi_strain_plasti
end_initia
...
post_calcul -materi_stress -sizedev -materi_strain_plasti -sizetot
...
control_timestep 1 ...
control_print 1 -node_dof_calcul

will print records like

node_dof_calcul index 0.2 1.1e-4

Here the 0.2 is the equivalent Von Mises stress and 1.1e-4 measures the plastic strain matrix.