Deformation Coefficient kdef in Timber Design

In the serviceability limit state design 1b), the deformation w_fin is calculated from the deformation components w_creep and w_inst; in RFEM 6, the component is off.

The calculation of the creep deformation w_creep includes the deformation coefficient k_def, which depends on the material used on one hand, and on the service class on the other hand.

The deformation coefficient k_def is preset with 0.6 by default, and does not change automatically with respect to the service class.

In order to use the correct k_def value for the serviceability limit state design, it is necessary to adjust the settings of the National Annex.

In this case, it is important to pay attention to which structural component corresponds to the worst (highest) service class.

Timber Design, kdef