How is it possible to avoid singularities on membrane surfaces from form-finding?

Answer

Singular reactions are induced by inappropriate form-finding data on membrane edges and an unfavorable FE mesh.

  1. If a cable with unfavorable form-finding settings (extreme sag or insufficient force) is applied to a membrane edge, the membrane surface is unusual in the form-finding process and results in a non-optimally arranged FE mesh with corresponding singular force reactions.

    Figure 01 - Unfavorable Setting of Form-Finding

    In this case, you have to adjust the form-finding settings of the membrane and the boundary element to each other.

  2. The form-finding process starts with the initial FE mesh design. If this arrangement is already unfavorable in advance and does not correspond to the necessary shape parameters, the force corresponding to the found shape is also negatively affected.

    Figure 02 - Wrong Mesh Design

    In this case, adjust the base geometry so that the initial mesh corresponds to all shape parameters.
The graphical display of the mesh quality before and after form-finding can be activated in the Display Navigator.

Mesh Quality

Keywords

Singularity Form-finding Mesh quality

Downloads

Contact us

Contact Dlubal Software

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.

(267) 702-2815

info-us@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