pga-cut-off freq

02-Analytical capabilities
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parz
Posts: 7
Joined: 18 Feb 2013, 11:12

pga-cut-off freq

Post by parz »

Dear Seismosoft,
Im trying to normalize the spectrum to the certain pga value of the Acc.TH and at the cut-off frequency (35Hz) the pga value is about 1.5 times higher. How can I normalize the spectrum for a pga at the certain frequency by Seismosignal?
Thank you!
huffte
Posts: 978
Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
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Re: pga-cut-off freq

Post by huffte »

Hi parz. Can you clarify your question? It is not clear what you mean by "pga at the certain frequency".

If you wish to take a particular time history and scale it so that the pga of that time history is 1.0 g, then simply:

1. load the original time history
2. generate the elastic spectrum
3. look at the maximum acceleration in the ground motion parameters
4. go back to the "Time Series" tab
5. in the time vs. acceleration data region, select any cell, right click, and choose scale accelerogram.
6. enter the inverse of the acceleration from step 3 as the scale factor
7. select file -> save accelerogram as
Tim Huff
parz
Posts: 7
Joined: 18 Feb 2013, 11:12

Re: pga-cut-off freq

Post by parz »

Thanks huffte,
look, I have acceleration TH with amax=0.055g (after TH scalling), so when i create elastic spectra this amax value appears at 100Hz (as a zero peak ground acc.). However, I need this zero pga value at 33Hz and by arranging min period as 0.03 (to "normalise") acceleration at 33hz become higher.
It is possible to normalize by excel, anyway, how to arrange zero pga=0.055g at 33Hz.
Thank you very much.
parz
Posts: 7
Joined: 18 Feb 2013, 11:12

Re: pga-cut-off freq

Post by parz »

Hi, in Seismosignal Settings-Response Spectra - Period range assigning Min Period as 0.03, however the PERIOD Series in the table again starts from 0.0. How may I shift periods to up or eliminate zero period value from the column without changing Spectra values sreie.
Thank you very much
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: pga-cut-off freq

Post by seismosoft »

We are afraid that the level of customisation that you require is currently not available in SeismoSignal, and that you will thus have to introduce such post-processing fine-tuning outside of the program.

Seismosoft Support
parz
Posts: 7
Joined: 18 Feb 2013, 11:12

Re: pga-cut-off freq

Post by parz »

Thank you very much!
HAMID121
Posts: 2
Joined: 22 Mar 2018, 13:16

Re: pga-cut-off freq

Post by HAMID121 »

Hi,

I'm trying to process strong motion data of an earthquake. Is it possible to determine corner frequency in SeismoSignal to calculate the Brune Stress Drop?

Thanks,
Hamid
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