993x
005006
2021-05-13

Unstable Model

I have a model of a timber building, which I have transferred from Scia Engineer and adapted into the RFEM program. The models should be the same; however, it can only be calculated in Scia Engineer, while RFEM reports singularity. How do I edit the model to analyze it in RFEM?


Answer:
Instability is caused by the fact that all members with a hinge at the member end converge in one node. This means that the node can rotate freely. It is necessary to connect at least one member to a node without a hinge.

You could also solve this problem by setting a certain small stiffness at the hinge, so that it is not freely rotatable. In that case, there can be hinges on all members at the node.