Is it possible to find the form-finding of the membranes without having to consider the semi-rigid supporting structure?

Answer

Generally, the form-finding process in RFEM always considers all model data. In the form-finding, the elastic supporting elements on the membrane react with deformations in the direction of the acting membrane tensile stress. The integral process passes the prestressed model for the subsequent calculation if the forces of all deformed elements are in equilibrium with the membrane geometry below the specified prestress.


Figure 01 - Form-Finding with Deformed Supporting Structure

However, the flexibility factor of the supporting structure can be suppressed for the pure form-finding by means of support structure's non-linearity 'Form-Finding Stage Only' (also called form-finding support) at the membrane edges.


In this case, the form-finding process results in a shape whose prestress is in equilibrium with the set form-finding support forces and remaining boundary reactions.


For the structural analysis of all other load cases and combinations, the form-finding supports are deactivated and the form-finding support forces are applied as external loads to maintain the global equilibrium on the entire model.

Due to the removal of supports, the membrane reacts with the semi-rigid supporting structure in the subsequent analyses (LC and CO). Without additional loading, this reaction is similar to relaxation with an associated prestress reduction.




Keywords

Form-finding Support Supporting construction Supporting structure Elasticity Prestress Membrane

Downloads

Contact us

Contact to Dlubal

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

+49 9673 9203 0

info@dlubal.com

RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

Price of First License
3,540.00 USD
RFEM Tensile Membrane Structures
RF-FORM-FINDING 5.xx

Add-on Module

Form-finding of tensile membrane and cable structures

Price of First License
1,750.00 USD