In the Surfaces tab of the 'Serviceability Configuration' dialog, you specify the limit values that apply to the deformations of the surfaces.
As for the members, there are various design situation types for serviceability limit state designs, which differ depending on the design standard. You can define specific limit values for the deflections for each combination type. They are related to the lengths of the components.
The list next to the 'Definition type' contains several options for the form in which a limit value can be defined (see image Determine reference of deformation):
- Relative value: The limit value is defined relative to the length of the surface.
- Absolute value: The value of the maximum deflection is specified directly.
- Sum of relative and absolute value: The limit value is the sum of the relative value and the absolute value.
- Min. of relative and absolute value: The smaller value of the relative or absolute value applies as the limit value.
- Max. of relative and absolute value: The larger value of the relative or absolute value applies as the limit value.
Depending on the support of the component – surface supported on both sides or cantilevered surface supported on one side – different limit values for the deflection are usually relevant. This support is to be defined as a 'Surface type' in the properties of the surface or the surface set in the Deflection tab. There, you can also specify whether the maximum displacements refer to the undeformed system, a deformed reference plane, or a parallel surface, and specify how the reference length is to be determined.
If necessary, adjust the preset limit values for the deformation analyses of the objects.