static time history analysis

03-Analytical/modelling capabilities
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sem.ma
Posts: 10
Joined: 15 May 2017, 16:40

static time history analysis

Post by sem.ma »

I have force-displacement history for a RC column which was published in Peer. When I create a displacement-time history and assigned it to the column in seismostruct, the results for shear force is very smaller than experimental data (adopted from force-displacement history). When I create a force-time history and assigned it to the column, the displacement which was reported by seismostruct was smaller than experimental data (adopted from force-displacement history). I think it was mistake by software. could you please help me why the results were different for displacement history and for force history, by software?
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: static time history analysis

Post by seismosoft »

Can it not be a problem with your modelling? (e.g. reinforcement, shear reinforcement, boundary conditions
The program has been extensively used and verified in all analysis types. Please check the verification report that is included in the installation of the software. You will realize that the program has been checks thoroughly.

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sem.ma
Posts: 10
Joined: 15 May 2017, 16:40

Re: static time history analysis

Post by sem.ma »

Thank you for your prompt response. I have only one model. For this model, two history curve has been defined. One based on displacement-time history, and one for force-time history. All of thing are same. Curve factor is also =1. I did the STH analysis for each of these curves separately.
As mentioned before, I can't understand that why the results were different for these two curves. I thing there is a problem, but I can't find it. Could you please help me more? Is it true that the results for TH analysis was different in this case while these two curves adopted from one force-displacement history?
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: static time history analysis

Post by seismosoft »

Without knowing the details of your model we cannot really tell what is the difference. We would recommend that you start from one model and start changing it gradually until you get to the other model, e.g. initially change the section type, then the loading etc. It will help you realise what you are doing wrong.

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margo
Posts: 2
Joined: 11 Oct 2017, 19:23

Re: static time history analysis

Post by margo »

Dear Seismosoft Support
I applied a displacement time history and ran a static analyses on one of your template bridge piers in seismostruct.
the problem is that from the yield point it does not give any shear responses in the support. But since the material you have defined for steel is th mengotto-pinto model, it should have forces after the yield point! Can you help me with this?
thanks
Margo
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seismosoft
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Joined: 06 Jul 2007, 04:55

Re: static time history analysis

Post by seismosoft »

Hello Margo,
It is not clear what you mean with "it does not give any shear responses in the support".
Note that the shear demand after the bending moment yield will not increase since there is no increase in the bending moments.

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margo
Posts: 2
Joined: 11 Oct 2017, 19:23

Re: static time history analysis

Post by margo »

Dear Seismosoft Support,
Thank you for your response.
What i meant is that the shear value for the support is equal to zero, from the yield point to the end of the analyses. the shear output is sth like this:
6.44507225 60.45422095
6.44702235 60.76189709
6.44897245 60.82272397
6.45092255 0
6.45287264 0
6.45482274 0
6.45677284 0
6.45872294 0
and in t=6.44897245 the software announces that the yield point has been reached. But since the material you have defined for steel is the mengotto-pinto model, it should have forces after the yield point!
Kind regards,
Margo
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seismosoft
Posts: 1184
Joined: 06 Jul 2007, 04:55

Re: static time history analysis

Post by seismosoft »

Can it be that you have set performance criteria with no residual strength?
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