Model modifiers

The Model modifiers may be used to locally change the stiffnesses parameters of the model.

Two different types of model modifiers is possible to apply on structural elements (1D/2D members, ...) in form of the additional data: the Absences representing complete exclusion of elements from the analysis (i.e. the stiffness is set to zero), and the Stiffness modifications multiplying the stiffness parameters of elements by the Stiffness factors.

Compared with the Property modifiers, both types of model modifiers can be considered just in certain load cases using the concept of Modification groups. The model modifiers stored in a modification group are taken into account in the analysis only for those load cases, where this modification group is assigned (as part of load case properties). Using such approach, you can simulate different stages of the structure (like presence of concrete cracking or missing steel bracing) without necessity to create separate models for each design situation.

Warning: Be aware, that the Model modifier and the Property modifiercan be applied on the same structural element. In such case, the stiffness parameters are not derived by combining the effect from both entities, but the model modifier determines stiffness in the load cases which have assigned the modification group, while for the rest of the load cases is used the property modifier.

Enable model modifiers in project

To allow Model modifiers functionality in the project, it's necessary to just have such option activated in Project data dialog:

  1. Go to Tree > Project to display Project data dialog.
  2. Click on tab Functionality and check the option Model modifiers in the available list.

Apply model modifier to structural element

To apply Model modifiers on some structural element do the following:

  1. Go to the Tree > Model modifiers > Model modifiers to access the service.
  2. Select the Modification group from the available list, where the modifiers will be stored.
  3. Click on the Model modifiers > {Absences, Stiffness modifications} to display the dialog for creating a new model modifier entity.
  4. Fill the required properties depending on the selected type of modifier and confirm the dialog.
  5. Select the structural element(s) on which the modifier should applied.

Note: Be aware, that Stiffness modifications are available only for PPE 'default'.