!OpenSees Limitation!

[AHARSHIAN]

Hello,

I have modeled a 3D RC frame building with 52000 nodes. When I was running it in the OpenSees, the program has bee crashed and stopped working even in Modeling Procedure!
I have decided to reduce the size of the model and for the second time, I have reduced the number of the nodes to 11000 nodes but the program stopped working in the Analysis Part. For the third time, I have remodeled the project with 3000 nodes, but it didn't analyze the structure again!

My question:
What is the limitation of the OpenSees in Large Models?

Appreciate your prompt answer.

[vesna]

I know for OpenSees examples with as many as 100,000 nodes. If you have a problem even with 3000 nodes and if your eigen analysis is failing that indicates the problem within your model. Check connectivity of your elements and boundary conditions. I would also suggest you to use display recorder command (http://opensees.berkeley.edu/wiki/index ... ode_shapes) to create graphical image of your model.

[AHARSHIAN]

Dear Vesna,

Thanks for your answer,

I have checked the model, it has no problem. It works if I reduce the number of the nodes and consequently number of shell elements and BeamColumn elements. The problesm in the big-size model is that the programe doesn't give me any error! It crashes and stops working. Therefore; there will be no choice just closing the programe!

I am going to model Slab Elements with very fine grillage system consisting of Elastic BeamColumn elements. In this case, I will be able to transfer the vertical loads from the slab to the perimeter beams.
Maybe you could suggest me something else!

How could I model vertical loads transferring from slab to the beams in a 3D building!?

Appreciate your help in advance.

[AHARSHIAN]

Hello Friends,

I am sorry if I am asking this question for several times! I really need your help!

Does any body have an opinion regarding Slab-Modeling! If I use Shell-Elements, then I will not be able to apply surface loads on them. Therefore; I am trying a very fine grid system of Elastic Beam-Column Elements. The problems is that when I make the model in OpenSees, the program crashes during analysis, I think it has a problem regarding model size but there is no error or warning message to be sure of that! If I reduce the size of the model, it works properly but then it will be a very coarse grid system which does not represent the slab model at all.

What could I do?
Appreciate your help.

[fmk]

send me the model

fmckenna ATTTTTT ce DOTTT berkeley DOTT edu

[AHARSHIAN]

Dear fmk,

I have sent the files to your E-mail.

Appreciate your help in advance.

[huangchuanteng]

AHARSHIAN wrote:
> Hello Friends,
>
> I am sorry if I am asking this question for several times! I really need
> your help!
>
> Does any body have an opinion regarding Slab-Modeling! If I use
> Shell-Elements, then I will not be able to apply surface loads on them.
> Therefore; I am trying a very fine grid system of Elastic Beam-Column
> Elements. The problems is that when I make the model in OpenSees, the
> program crashes during analysis, I think it has a problem regarding model
> size but there is no error or warning message to be sure of that! If I
> reduce the size of the model, it works properly but then it will be a very
> coarse grid system which does not represent the slab model at all.
>
> What could I do?
> Appreciate your help.
hi,AHARSHIAN
recently i came across the simulation of slab-beam-column joint with Opensees, it makes me confused and depressed.
and in china, i find same paper that simulate the slab by beam grillage which i think is almost the same as your previous
idea. but my focus is the slab, so the approximation method is not suit for me. and i want to know, do your find some
appropriate method to simulate the slab by Opensees, and my e-mail: chuantenghwang@yahoo.com
Hope to hear from you! best wishes！