FAQ 000468 EN

Calculation DYNAM Pro - Natural Vibrations RF-DYNAM Pro - Natural Vibrations

For the dynamic calculation of a single-span beam, I get the message:

"Too many eigenvalue required, maximum number = 0 ...".

However, I just specified one eigenvalue for determination!

Answer

The natural vibrations of the single-span beam cannot be determined if the masses act only in the Z-direction and the internal member partition is defined as "1." The displacement component of the member in Z-direction can be determined only with an internal member division greater than 1.

Alternatively, you can divide the member in RSTAB by nodes and thus create several partial members. In this way, you can determine the natural frequency also for a member division of "1" at the intermediate nodes.

RSTAB Dynamic Analysis
DYNAM Pro - Natural Vibrations 8.xx

Add-on Module

Dynamic analysis of natural frequencies and mode shapes of member models

RFEM Dynamic Analysis
RF-DYNAM Pro - Natural Vibrations  5.xx

Add-on Module

Dynamic analysis of natural frequencies and mode shapes of member, surface, and solid models