Defining target spectrum - damping

02-Analytical capabilities
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msavor
Posts: 11
Joined: 06 Sep 2010, 09:20

Defining target spectrum - damping

Post by msavor »

Hello,
I am trying to define vertical target spectrum EC8 with 2% damping. Is it possible or predefined value is 5%? I tried to change it in Settings but it seems it has no effect.

Thank you in advance for help!
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: Defining target spectrum - damping

Post by seismosoft »

Hi,

We are not sure we understand fully your query. What do you exactly mean with "define vertical EC8 target spectrum"?

In the current version of SeismoMatch, one cannot really generate a vertical EC8 target spectrum - one will rather have to load it from a file.

Do let us know, perhaps explaining in better detail what is it exactly that is happening. If you need/want to send us illustrative screenshots, use support@seismosoft.com.

Seismosoft Support
msavor
Posts: 11
Joined: 06 Sep 2010, 09:20

Re: Defining target spectrum - damping

Post by msavor »

I am sorry, I was absent for some time.

So, I wanted to match vertical components of ground motion to vertical EC spectra with 2% damping. How is it possible? If I load spectrum from file, it seems that during matching it is automatically assumed that my loaded spectrum is spectrum with 5% damping. How can one avoid it? I can define that damping value is 2% (in response spectra menu), but that can be done after the matching, so it does not affect matching.
huffte
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Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
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Re: Defining target spectrum - damping

Post by huffte »

Hi msavor. I think you can accomplish what you wish. If you look in the Response Spectra tab you will see that you can vary the damping ratio there. If I have interpretted things correctly, you can change the damping on that tab to the value you wish to be used for analysis. You must change it BEFORE doing the matching, but AFTER definign the spectrum from file. And you MUST hit REFRESH after changing the damping and prior to doing the matching.
Tim Huff
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: Defining target spectrum - damping

Post by seismosoft »

In the upcoming release of SeismoMatch, it will be rendered more evident that the viscous damping that is considered in the matching process is that specified in the 'Define Target Spectrum' module.

In the 'Response Spectra' module, instead, changes in damping value serve only the purpose of allowing users to visualise the records spectra at different levels of damping, but no modifications are introduced to the target spectrum nor is the matching re-run.

Seismosoft Support
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