# PARAM, POSTEXT

Bulk Data Entry Outputs the modal complex stiffness matrix and modal viscous damping matrix to the OUTPUT2 results file.

Parameter Values Description
POSTEXT <YES, NO>

Default = NO

If YES, the modal complex stiffness matrix (KHH) and, if it exists, the modal viscous damping matrix (BHH) are written to the .op2 file when frequency response analysis is performed.

The modal complex stiffness matrix is:

$\left[\text{KHH}\right]={\left\{\Phi \right\}}^{\text{T}}\left(\left[\text{K}\right]+\text{iG}*\left[\text{K}\right]+\text{i}\left[\text{Kge}\right]\right)\left\{\Phi \right\}$

Where, G is the PARAM, G structural damping value and [Kge] is the structural damping matrix based on the structural damping values on the MATi data.

The modal viscous damping matrix is:

$\left[\text{BHH}\right]={\left\{\Phi \right\}}^{\text{T}}\left[\text{B}\right]\left\{\Phi \right\}$