How to determine ω3 & ω4 values in Transient analysis

Parthiban B

 

In direct transient analysis, how do I determine the appropriate values for ω3 and ω4?

where:

ω₃ = Frequency of interest for converting over structural damping into viscous damping

ω₄ = Frequency of interest for converting element damping coefficient into viscous damping

What factors should I consider when selecting these frequencies to convert structural damping to viscous damping and element damping coefficients into viscous damping?

Rajashri_Saha

Hi Parthiban,

Usually, it is advised to enter same values for w3 & w4.

You can calculate this as w3=2*Pi*(1st Natural frequency). You can get the 1st natural frequency value from Modal Analysis.

Thanks

Rajashri