The OpenSees Community

Dear Vesna, I have modeled a 3D bracing structure, and I got the foloowing warrning, ForceBeamColumn3d::ForceBeamColumn3d-- no torsion detected in sections continuing with element torsional stiffness GJ/L=1e010, what does it mean? and how should I solve it? also it must be metioned that I have defin...

Dear Vesna, I have modeled a 3D bracing structure, and I got the foloowing warrning, ForceBeamColumn3d::ForceBeamColumn3d-- no torsion detected in sections continuing with element torsional stiffness GJ/L=1e010, what does it mean? and how should I solve it? also it must be metioned that I have defin...

Dear Vesna, Sorry, I am asking lots of question. 1- I used fiber sections and nonlinear elements to model my structure. I want to know dimention of sections affect the structural results. I mean If I use elastic elements(in elastic elements we just define A E G I ..., but we dont define section dime...

you wrote: If you are using forceBeamColumn or dispBeamColumn element you can assign different sections to the element at the locations of integration points.

could you please give me an example about how to assign diffrent sections to the nonlinear elements.

hi, how can I define difrent sections along a beam lengh. and also how can i define non-prismatic sections along a element. actually I want to model the top and buttom plates of beams. I devide each beam to three elements and assigned difrent sections to each one of them. in this way when i check th...

thank you vesna, how about geomtrans command. I want to affect the effects of P-(small or big)delta and bucling in my model( I need to focus on both local and global responses of the structure). which one of the geom trans coomands do you reccomand for diffrent elements. I used corrotational for bra...

hi, thanks. it was because of heystertic material. but this too strange. i think it was because of damage and pinching factor. but we do not expect so much damage after just one step pushover analysis. anyway I changed the material to steel01, and now this is ok. thank you anyway. have you ever defi...

hi, I have the same problem, and I used truss elemenets to model rigid diphragm in 2D model. but after the first step the 1mode periode decrease from 1.02 to 0.95 I just used equalDOF to model simple connection of my model. ( in one of the bays of my model, beams are pinned to the columns and in the...

Thank you very much, you have helped me alot so far, but still I have many questions regarding to your answers. >When using nonlinear elements I would not recommend you using a equalDOF to simulate a rigid floor (you can find discussions on this topic on the message board). >Instead I recommend defi...

hi,
is there anybody help me

Dear Vesna, I want to model a 2-D bracing frame. I have defined lumed mass for each storey and put it on one of each floor nodes. I used EqualDof to consider the diafragm.(all of the nodes in each floor have the same displacement because, in the main model which is a 3-D model we have diaphragm). so...

ok
thanks alot

thanks

vesna wrote:
> To account for p-little delta effect there is no other way to account for
> it then by subdividing the element into smaller pieces.
ok
thank you very much
then, how many? for example a 4 meter column should be devided in how many elements?
is there any suggestion?

Dear Vesna, I want to model a 2-D bracing frame. I have defined lumed mass for each storey and put it on one of each floor nodes. I used EqualDof to consider the diafragm.(all of the nodes in each floor have the same displacement because, in the main model which is a 3-D model we have diaphragm). so...