Assigning moment/force releases

[Soydan]

Dear Seismosoft,
I'm using Seismostruct v6 for analyzing a single bay and single storey precast frame. I’m introducing moment releases to the ends of the beam and trying to execute eigenvalue and dynamic time history analyses. The eigenvalue analysis was carried out successfully but dynamic time history analysis is cutting at the beginning of the analysis. Do you have any recommendations on this issue?
Best regards.

[seismosoft]

Soydan, hi.

We are not sure we understand what do you mean exactly with "dynamic time history analysis is cutting at the beginning of the analysis", but wonder nonetheless if there could perhaps be a problem in your model with the definition of the 'time-history stages'?

Seismosoft Support

[Soydan]

Dear Seismosoft,
Dynamic time history analysis can't be performed with the assignment of moment/force releases. At the beginning of the analysis a warning appears and the analysis stops. By the way the analysis can be performed without releases.
Best regards.

[seismosoft]

Hi,

We have tried a model with end-releases, and it all ran fine. Send us your model, and we will try to find the time to identify what is it that is wrong with it (perhaps your structure lacks equilibrium).

Thanks,

Seismosoft Support

[Soydan]

I sent an e-mail to info@seismosoft.com with the same subject title including the analytical models.
Best regards.

[seismosoft]

Hi,

We looked into your model and quickly realised that it was unstable in the out-of-plane direction.

In other words, if you restrain the upper nodes (102, 108) in the y+rx+rz degrees-of-freedom, the analysis should run.

Seismosoft Support

[Soydan]

Dear Seismosoft,
Thank you for your attention. The model that I've sent to you is the preliminary case of a 3D analysis for a precast industrial building. In the final case of the analysis I will consider all of the frames that generate the whole structure and the three components of ground motion. I've already performed the DTHA with the whole structure and at the beginning of this analysis same warning appeared and the analysis stopped. Yes, the DTHA is running fine with restraining the upper nodes in the y+rx+rz for plane frame but for 3D analysis these degrees of freedom can't be restrained.
Best regards.

[Soydan]

The moment releases are working fine with the installation of the new version of Seismostruct. Thank you for the release of v6.5.
Best regards.