We provide hints and tips to help you get started with the basic program RFEM.
FAQ 000221 | My model is stiffened by tension members. The calculation is terminated with the message about instability. How can I finish the calculation?
Video
First Steps with RFEM
Question
My model is stiffened by tension members. The calculation is terminated with the message about instability. How can I finish the calculation?Answer
The calculation can be terminated due to an unstable structural system for various reasons. There can be a 'real' instability due to overloading the system, but the instability effects may also be caused by failing members.
In the calulcation parameters, you can deactivate the nonlinearity 'Members due to member type' (see Figure 01). If the calculation is then possible without the error message, the problem is probably caused by failing members.
Figure 01 - Deactivating Nonlinearities
The complete failure of the tension members can be prevented using the option 'Failing Members to Be Removed Individually During Successive Iterations' in the dialog box Global Calculation Parameters (see Figure 02). This should help in most cases. The number of possible iterations should be specified sufficiently large.
Figure 02 - Removing Failing Members Individually
An alternative method is to apply a prestress to the tension members to prevent the failure of them.
Keywords
Dlubal FAQ Instability Tension member Failure Abort Nonlinearity Error message Frequently Asked Question FAQ about Dlubal Question and Answer about Dlubal
Links
Write Comment...
Write Comment...
Contact us
Do you have any questions about our products or need advice on selecting the products needed for your projects?
Contact us via our free e-mail, chat, or forum support or find various suggested solutions and useful tips on our FAQ page.
