RSA2011 problem:drift ratio is zero

[a.balcu]

Can someone please help me understand why i always get 0.00 at the drift ratio in robot structural analysis 2011 d Ux=dr UX/h. At first i thought it was because of the units cm/m, but then a placed a precision of .0000 decimals and the result is still zero.
Can someone help me?

Thank you in advance

[length zero]

For which load case are u trying to control drifts.
Regards

[a.balcu]

seismic load. i didn't make any load combo's, just the simple load case

[mecheil2000]

I have same problem
I solved 40 floor tower But I got the same problem
all displacement in x-direction and in y-direction zero!!!

[waldemar.okapa]

Drift ratio is a comparatively small value, a few milimiters of displacement drift divided by a few meters column height. Set expotential format 1.0e+1 to see if it is really zero.

Attach here RTD example to share comments.

[mecheil2000]

Drift ratio is a comparatively small value, a few milimiters of displacement drift divided by a few meters column height. Set expotential format 1.0e+1 to see if it is really zero.

Attach here RTD example to share comments.

Thanks waldemar for Helping
But when I see The displacemnt of joints from
Results>Dispalcements
I see Ux Uy And Uz in cm all are zero which is not resonable for 40 floor tower
I can not upload model Because the size of model is about 100 MB

I would like to ask you if there any tips for modal analysis lead to this zero result
I checked material own weight of building rigid diaphragm every thing is ok

I select first Modal analysis and select default setting of program (UBC97 code)
Then I select Seismic analysis UBC code also in X-direction and Y-direction
For modal analysis I select Lumped mass without rotation

[mecheil2000]

Drift ratio is a comparatively small value, a few milimiters of displacement drift divided by a few meters column height. Set expotential format 1.0e+1 to see if it is really zero.

Attach here RTD example to share comments.

Thanks waldemar I did as you told me
But I see the displacement result in x and in y direction about 0.4 or 0.3 mm
It is not resonable result at all
Can you help

[waldemar.okapa]

Check the sum of reaction in the reaction table. It should be comparable with hand calculated seismic base shear or other estimated lateral loads.
Then you can check walls and columns sections or materials, maybesupports. It is hard to tell anything without the model.

[mecheil2000]

Check the sum of reaction in the reaction table. It should be comparable with hand calculated seismic base shear or other estimated lateral loads.
Then you can check walls and columns sections or materials, maybesupports. It is hard to tell anything without the model.

thanks waldemar for your helping and your efforts.
The total load of tower (self weight) about 92000 ton
but I see the total shear force is only 165 ton which means something is wrong

I think the problem is related to the modal analysis
can you tell me some tips for modal analysis to get a good results because I see in modal analysis there are 3 options
option1 : modal
option2: seismic
option3: presude

can you tell me which one I have to use

once again thanks for your helping

[troy_the.best]

edward,

assign dynamic mass ( x,y ) in define analysis parameters. try again. it will work.

[mecheil2000]

edward,

assign dynamic mass ( x,y ) in define analysis parameters. try again. it will work.

The problem with Rigid diaphragm
Thank you for your helping
See my post also in this link
http://forums.augi.com/showthread.php?p=1092710#post1092710

[iassoniako572844]

Ι have the same problem. I made a concrete cylinder model and i take reults such as -0,111 mm max Uz, and with elasticity E1=E/2 (creep) -0,244 mm. Something imposible i believe that can exist.
I will made the same model with SAP2000 and i will come with results.

Another solution is to put a displacement in the model manually. Loads-> Load Definitions->Bar->Displacements. I put a value about 0,5m (-Z) in order to see what will happen with Moments after a collapse.