Search found 5 matches

by ptr
Sun Apr 15, 2018 3:33 am
Forum: OpenSees.exe Users
Topic: 2d Dynamic non linear RC fiber model - Period too long!
Replies: 10
Views: 7874

Re: 2d Dynamic non linear RC fiber model - Period too long!

The problem seems to be solved!

There were some problems about the units and plus I didn't use any kind of rigid joint connection. Based on the examples founded on the web, I didn't think that it was necessary.
Is it really always necessary to use them?
Thank you all for your suggestions!
by ptr
Tue Apr 10, 2018 10:13 pm
Forum: OpenSees.exe Users
Topic: 2d Dynamic non linear RC fiber model - Period too long!
Replies: 10
Views: 7874

Re: 2d Dynamic non linear RC fiber model - Period too long!

Jhno wrote: > The solution to the eigen problem involes the M and K matrix. In my > understading (which might be wrong of course) unless your load bring a > modification to the rigidity matrix (yielding) there is no reason that > application of a load change the outcome of the analysis. I think so t...
by ptr
Tue Apr 10, 2018 12:07 pm
Forum: OpenSees.exe Users
Topic: 2d Dynamic non linear RC fiber model - Period too long!
Replies: 10
Views: 7874

Re: 2d Dynamic non linear RC fiber model - Period too long!

selimgunay wrote:
> Result of the eigenvalue analysis is not the period. It is w^2. You need to
> compute the period T as 2*pi/w.

Yes, I know it!
Indeed the period has been calculated in this way and unfortunately it is confirmed by the displacement's plot!
by ptr
Tue Apr 10, 2018 11:38 am
Forum: OpenSees.exe Users
Topic: 2d Dynamic non linear RC fiber model - Period too long!
Replies: 10
Views: 7874

Re: 2d Dynamic non linear RC fiber model - Period too long!

Thank you so much for your answer! I did what you suggested me, but it seems that the problem has nothing to do with the application of gravitational loads! Indeed, there are no differences between the results of the eigenvalue analysis before gravity loading and the results after it. I think that t...
by ptr
Mon Apr 09, 2018 1:19 pm
Forum: OpenSees.exe Users
Topic: 2d Dynamic non linear RC fiber model - Period too long!
Replies: 10
Views: 7874

2d Dynamic non linear RC fiber model - Period too long!

Hi everybody! I am a senior university student working on my last project. I tried to run non linear dynamic analises for a 2D RC fiber frame, based on some examples founded on web. After working a lot trying to make the analyses work, I found a problem that I really can't solve! Long story short, m...