Hello Caesar Users,

I am converting a time history profile [time(ms)--force(lbf)] from AFT Impulse output to [frequency(Hz)--DLF] in order to for me to know where is the peak frequency using the Interfaces --->AFT Impulse Utility.

My question is, does this utility already considers damping of 2% upon converting it? Because the only input that I can see are the following:

1) Maximum points on each DLF curve =(I set it to 30)
2) Frequency cut-off =(I set it to 200 Hz).

I am just curious because one of the beam analysis software, there is an option to set the "damping %".

I compare the results setting the damping ratio to 2% and the result closely matches with the Caesar Interface--->AFT Impulse result.

Is my assumption that the Caesar Interface ---> AFT Impulse utility already considers the 2% damping as default, is correct or I am misinterpreting the theory.

Many thanks and sorry if I have misinterpreted something.

Additional information, the output file from AFT impulse is in seconds & lbf...Does the unit in Caesar Interface AFT utility is sensitive to units...or it automatically reads whatever is on the FRC file..Many Thanks...

To my knowledge, there is no damping included in the CAESAR II DLF response spectrum generator.
You have to get the time units (milliseconds) correct in the DLF response spectrum generator but it is not sensitive to load units - we're after the "shape" of the load, consider it normalized.

Thanks Dave for the info...