In the Surfaces tab of the 'Serviceability Configuration' dialog box, you can set the limit values applicable to surface deformations.
As with the Members, various assessment situation types for serviceability checks exist, differing according to the design standard. For each combination type, you can specify specific deflection limit values. They are related to the lengths of the components. The list next to 'Definition Type' contains several options for defining a limit value (see image Specify deformation reference):
- Relative value: The limit value is defined relative to the length of the surface.
- Absolute value: The value of the maximum deflection is defined directly.
- Sum of relative and absolute value: The limit is the sum of the relative value and the absolute value.
- Min. of relative and absolute values: The smaller value of the relative or absolute value applies as the limit.
- Max. of relative and absolute values: The larger value of the relative or absolute value applies as the limit.
Depending on the support conditions of the component—double-sided supported surface or single-sided cantilevered surface—different deflection limit values are generally relevant. This support is defined as 'Surface Type' in the surface or set of surfaces properties in the Deflection tab. There, you can also determine whether the maximum displacements relate to the undeformed system, a deformed reference plane, or a parallel plane, and specify how the reference length should be determined.
If necessary, adjust the preset limit values for deformations checks of the objects.