RF‑FORM‑FINDING can be activated in the "Options" tab in the "Model - General Data" section. By activating the add-on module, a new RF‑FORM‑FINDING load case is created and an additional menu appears in the main program, allowing for the definition of prestress conditions for membrane and cable elements.
Question
How do I activate the RF‑FORM‑FINDING add-on module?
With the activated option 'Topology on Form-Finding Form' in Project Navigator - Display, the model display is optimized based on the form-finding geometry. For example, the loads are displayed in relation to the deformed system.
Activating 'Show Form-Finding' in the shortcut menu leads to an automatic preliminary form-finding according to the saved form-finding properties when you change the structure of membrane surfaces. This interactive graphics mode is based on the force density method.
More Information FAQIn RFEM, there is an option to couple surfaces with the stiffness types "Membrane" and "Membrane Orthotropic" with the material models "Isotropic Nonlinear Elastic 2D/3D" and "Isotropic Plastic 2D/3D" (add-on module RF-MAT NL is required).
This functionality enables simulation of the nonlinear strain behavior of ETFE foils, for example.
- Form-finding of:
- tension-loaded membrane and cable structures
- compression-loaded shell and beam structures
- mixed tension- and compression-loaded structures
- Consideration of gas chambers between surfaces
- Interaction with supporting structure (substructure design according to various standards)
- Surfaces as a 2D and members as a 1D element
- Definition of different prestress conditions for surfaces (membranes and shells)
- Definition of forces or geometrical requirements for members (cables and beams)
- Consideration of individual loads (self‑weight, inner pressure, and so on) in the form‑finding process
- Temporary support definitions for the form-finding process
- Automatic preliminary form-finding of membrane surfaces (more information...)
- Definition of isotropic or orthotropic material for structural analysis
- Optional definition of free polygon loads
- Transformation of form‑found shape elements into NURBS surface elements
- Possibility of combined form-finding by integration of preliminary form-finding
- Graphical evaluation of the new form using colored coordinates and inclination plots
- Complete documentation of the calculation including user-defined adaptive evaluation figures
- Optional export of the FE mesh as a DXF or Excel file