natural frequency of a cable stayed bridge

[kww2008]

I am trying to get an idea of the natural frequency of a cable stayed footbridge using a commercial structural analysis software and the software could not calculate the frequency owing to the structure having cable elements. I changed the cable elements to "tension only" elements and the software was then able able to determine a natural frequency.

Has anyone came across this when trying to get the natural frequency of a cable-stayed structure using software applications?

Since the behavior of a cable stayed structure has significant geometric non-linearity, does the natural frequency determination need to take this non-linearity into consideration ?

 

[yakpol]

Frequency analyisis is typically elastic analysis. Most softwares will not take even tension only elements.