FAQ 000088 EN

Calculation RF-FE-LTB FE-LTB

When I tried to pick the imperfections in FE-LTB, the message "Diagonal coefficient of matrix < 0"="" was=""> What have I done wrong?


This message shown in FE-LTB means that your system is numerically unstable.

Often, such an instability in FE-LTB can be explained by inaccurate support conditions or release definitions.

The determination of the critical load factor provides the stability load of the analyzed structural system.

In the numerical calculation, this stability load is characterized by the fact that either the determinant of the stiffness matrix becomes zero, or that very high deformations occur for very small load increases in the calculation.

Contact us

Contact to Dlubal

Have you found your question?
If not, contact us or send us your question via the online form.

+49 9673 9203 0


First Steps

First steps

We provide hints and tips to help you get started with the main programs RFEM and RSTAB.

Your support is by far the best

“Thank you very much for the useful information.

I would like to pay a compliment to your support team. I am always impressed how quickly and professionally the questions are answered. In the industry of structural analysis, I use several software including service contract, but your support is by far the best.”