Spectrum Definition For Doing DYNAMIC ANALYSIS

Dear ALL,

For doing Dynamic analysis

We are Defining the Spectrum in the SPECTRUM DEFINITION.

In Spectrum Definition, The user has a option for selection of Range Interpol and ORDINATE interpol in that on what basis i have to decide whether i have to select LINEAR (OR) LOG..


Thanks,
Durga.

This information must be from your spectrum.

Ohliger,

can you please Eloberate ..

Example :
If you have a pre definded spectrum from a seismologe then the acceleration and frequencys are log or lin in the ordinate /range.
So you give this interpolation methode in your input.

hello Ohlinger,
Good morning.

So, user spectrum should be in this manner..

RANGE:

10
100
1000
10000

ohlinger give me one example spectrum, where you used LOG in for selection of Range Interpol and ORDINATE interpol

You must self know is your Range log or lin presentation.
Normaly it is lin.

yes, normally it is linear

till now we used linear only but where LOG ??

iam not getting that..

The USNRC Reg Guide 1.60 spectra were, are log-log. The B31.1 Appx.II DLF spectrum is log-lin or lin-log, whatever.

Dave,

Thanks for your reply,

CAESAR provides some Inbuilt spectrums like 1.60 spectra, Elecentro etc..

I didnt find these spectrums in CAESAR INSTALLATION place..

can i know where these spectrum are available?

Those spectra are data built into the program (EXE), this data does not exist in an external file.

In Spectrum Definition, The user has a option for selection of Range Interpol and ORDINATE interpol in that on what basis i have to decide whether i have to select LINEAR (OR) LOG..

can any one give me reference about LOG or LIN, how to select..

If I understand well, your main question is "on what basis i have to decide whether i have to select LINEAR (OR) LOG".

I think you don't need to decide such things except cases in which you construct completely your own spectrum, I mean you consider your spectrum instead to take one from a document.

For example, just open REGULATORY GUIDE 1.60 "DESIGN RESPONSE SPECTRA FOR SEISMIC DESIGN OF NUCLEAR POWER PLANTS" and see FIGURE 1/HORIZONTAL DESIGN RESPONSE SPECTRA" where spectrum (graph representation) is log-log.

Thanks marioq.

I will go through it once..

Good morning Marioq,

I have seen that graph, still iam in confusion mode..

Can you give me any simple example spectrum..

LINEAR means straight line, or LOG means CURVE like that..

kindly give me one simple example....

It's about logaritmic scale of axis.
Please see
http://en.wikipedia.org/wiki/Logarithmic_scale

Its clear

Thank you