# Determination of Internal Forces for Plates: Torsional Stiffness

### Tips & Tricks

001142 11/10/2015

In a plate with full torsional stiffness, a significant part of loads is transferred by torsional moments. If it is not possible to set the positive effect of this additional stiffness in the calculation (for example, due to a butt joint of a precast plate in the stiffness area), you have to reduce the torsional stiffness.

For this, use the “Orthotropic” stiffness of a surface in RFEM. In the K33 text box, you can specify the factor D33 for torsional stiffness about the axes x' and y' in the stiffness matrix.