I have some questions regarding time history spectrum generation; by choosing user defined time history wave form, one is able to enter the time vs force/force ordinate. what comes out of the generator,is a frequency vs force/ force ordinate graph. I am fully aware of the importance of this new spectrum since it enables us to see whether or not we have chosen the right frequency range for the spectrum and also for the frequency cut off range.
my first question is; how does CII convert the data? (I know that f=1/T but, I got different results) obviously, the time history spectrum should be time vs force hence one has to change the range and ordinate types on the spectrum definition tab.
my second question is; does one have to re-enter the data into the converted spectrum? or is there any short cut way? I am working on a system in which there are 15 spectrums and the whole procedure is very time consuming.

regards

As per my understanding DLF spectrum generator performs the automatic integration of duhamel's integral .Please refer Coade Mechanical Engineering Newsletter,November,1994 .

If you are doing time history analysis then you do not need to generate the spectrum . Only you have to input the value of time history wave for through ENTER/EDIT Spectra Tab .