For Records Larger than 32768 lines issue

03-Unexpected behaviour/errors
Post Reply
Kirkaguel
Posts: 51
Joined: 31 Dec 2018, 10:04

For Records Larger than 32768 lines issue

Post by Kirkaguel »

Hi Technical support,

I encountered this issue were the message states "For records larger than 32768 lines, the Fourier and Power Spectra, as well as the Mean period Tm cannot be calculated" any possible solution how to go about this issue?

Although I can still save the corrected time series but I cannot see the Fourier and Power Spectra.
User avatar
seismosoft
Posts: 1056
Joined: 06 Jul 2007, 04:55

Re: For Records Larger than 32768 lines issue

Post by seismosoft »

Indeed, the maximum number of lines that can be accommodated by the Fourier and Power Spectra algorithm is 32768, because of internal limitations of the algorithm.

Seismosoft Support
Kirkaguel
Posts: 51
Joined: 31 Dec 2018, 10:04

Re: For Records Larger than 32768 lines issue

Post by Kirkaguel »

seismosoft wrote: 05 May 2022, 20:23 Indeed, the maximum number of lines that can be accommodated by the Fourier and Power Spectra algorithm is 32768, because of internal limitations of the algorithm.

Seismosoft Support
Any possible solution maybe to alter the original ground motion record? This is maybe because the time duration of the ground motion is long? the time step is pretty standard at 0.01. Is it possible to cut off the duration of the original ground motion to lower the maximum number of lines however my concern is that the resulting ground motion will no longer be usable for evaluating residual strength and displacement of the structure.
huffte
Posts: 941
Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
Contact:

Re: For Records Larger than 32768 lines issue

Post by huffte »

If you trim off the beginning and the ending 'insignificant' portions of the record, you may still be able to use it. The trick. of course, is in determining which portions are "insignificant' at both ends. Once you have it trimmed won to an acceptable number of points, you could run some 'response time histories' from the 'elastic/inelastic response spectra' tab for both the original, untrimmed record, and the trimmed record and compare residual displacements and inelastic spectra for the two records.

Another option is to double the specified time step and read only every other data point, which would cut the record length in half. Of course, you would want to compare again the untrimmed and trimmed record results for a series of analyses, both inelastic spectra nd response time history.
Tim Huff
Kirkaguel
Posts: 51
Joined: 31 Dec 2018, 10:04

Re: For Records Larger than 32768 lines issue

Post by Kirkaguel »

huffte wrote: 08 May 2022, 21:46 If you trim off the beginning and the ending 'insignificant' portions of the record, you may still be able to use it. The trick. of course, is in determining which portions are "insignificant' at both ends. Once you have it trimmed won to an acceptable number of points, you could run some 'response time histories' from the 'elastic/inelastic response spectra' tab for both the original, untrimmed record, and the trimmed record and compare residual displacements and inelastic spectra for the two records.

Another option is to double the specified time step and read only every other data point, which would cut the record length in half. Of course, you would want to compare again the untrimmed and trimmed record results for a series of analyses, both inelastic spectra nd response time history.
Hi Tim I will give your suggestion a try although right now we are still able to use the corrected ground motion records for structural analysis since we can still save it. Thanks
Post Reply

Return to “03-Unexpected behaviour/errors”