One way span slab model

[ricardo_urjais]

Hi Guys!

I am having trouble when modeling a one way slab model. I have been reading the posts :

-http://forums.autodesk.com/t5/Robot-Structural-Analysis/Floors-span-direction/td-p/3349655

- http://forums.autodesk.com/t5/Robot-Structural-Analysis/Force-Slabs-to-Span-One-Way/td-p/3515468

However, I am not having the same results these users had. My model is attached, can someone tell me what am I doing wrong? I had no trouble generating the mesh (just something about the stories where the elements are). When I ask for results, I simply have zero Moments in yy and xx. Shouldn't I have a lot more moments in xx axis? I have changed the local panel direction, changed the orthropy, tried with different loads, and nothing happen. I tried already the RLink issue, but didn't turn anything new for me...

Can someone tell me what I am doing wrong?

Thank you all.

[Artur.Kosakowski]

You need to apply load directly to the slab rather than to supports.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[ricardo_urjais]

I don't think it's because of that. If I change the slab type, p.e. to a shell analysis floor with homogeneous thickness, the stresses are pretty wise..Moreover, if I want to define a surface load, that's the way it is presented.

Any other suggestions?

[Artur.Kosakowski · Accepted solution]

I don't think it's because of that. If I change the slab type, p.e. to a shell analysis floor with homogeneous thickness, the stresses are pretty wise

so you changed the load distribution method from loads being transferred directly to support (trapezoidal and triangular method) to being applied to the elements of the panel's mesh. See the green and red boxes on the picture I attached previously.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[ricardo_urjais]

In all other examples that I posted in the very beginning of this post, the other users say it's imperative to select the "Simplified transfer of loads" in order to make the slab work only in one direction, so is that no true? Is acquarate enough to just define the orthropy tickness for the slaband select the X direction (in this case)?

[Artur.Kosakowski]

I think you must have misunderstood these comments. Please check the message 4 from http://forums.autodesk.com/t5/Robot-Structural-Analysis/Force-Slabs-to-Span-One-Way/m-p/3515468

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[ricardo_urjais]

I got it, but now I am trying the slab to work in y direction (just to test and see the values difference). I made the "reversal" options: -> selected orthotropic -> Y direction ->n1=0,001 ; n2=1 -> I kept the local system the same and no change in the calculation model. Shouldn't now the moments be much bigger in My? I am getting the same results as in the orthotropic direction X.

[Artur.Kosakowski]

See the attached pictures.

[ricardo_urjais]

Thank You!

Very informative for real 🙂