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FAQ 004849 | How to model a cable net structure in using the RF-FORM-FINDING add-on module?
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How to model a cable net structure in using the RF-FORM-FINDING add-on module?Answer
Because a net requires multiple cable segments to be modeled in a grid-type pattern, the cables are not one continuous member. This is not ideal for the RF-FORM-FINDING module as the cable prestress properties such as sag, target length, or force are best applied to a single cable segment. The program cannot easily apply these settings to a cable that is broken down into multiple segments along its length.
The best option to model the net in RFEM is to instead use a surface element. The material and stiffness properties of the surface are the equivalent properties to that of the net provided by the manufacturer. RF-FORM-FINDING can then be applied to the surface element such as a prestress force or stress.
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Dlubal FAQ Cable Net Form-finding Frequently Asked Question FAQ about Dlubal Question and Answer about Dlubal
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The RF‑FORM‑FINDING add‑on module can be activated in the ‘Edit Model - General Data’ window, ‘Options’ tab. By activating the 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.
Display of Topology on Deformed Structure
With the activated option "Topology on form-finding shape" in the 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.
- How to model a cable net structure in using the RF-FORM-FINDING add-on module?
- After the form-finding, I have exported the deformed shape to a DXF file and found that the results of the DXF file do not correspond to RFEM. What is the reason?
- Is it possible to export the form-finding results? For example in a DXF file?
- I would like to calculate and design "temporary structures." What do I need for this?
- I have already divided my membrane roof into individual surfaces. Can I quickly create a cutting pattern from these surfaces?
- How is an inflatable object simulated in RFEM?
- How can I define a material allowance at the edge of a cutting pattern?
- I have modeled a structure made of outer and inner cables as well as membranes, and get a message about instability or the error message "Jacobi matrix is not positive definite" in the RF‑FORM‑FINDING add-on module. What should I do?
- Why does the FE mesh of my conical membrane look like angular after the form-finding?
- Which Dlubal Software programs are required to calculate membrane and tensile structures?
