Slab Supported By Beams

[tclat]

Dear All,

I'm new to SAP2000 and I'm trying to model a slab supported by beams on three sides and a wall on one side.

Is there a way to restrain the edge only on one side (the wall) automatically?

When I run the model, the results show that the slab is bending more in the long direction which does not make sense. If I restrain all edges, the numbers seem to make more sense where the slab forces are larger in the short direction.

I've also tried to model a continuous one way slab supported on beams (two bays). In this case, the slab has no negative moment above the interior beam support and again the largest forces are along the long span of the slab which is not correct.

Am I doing something wrong or is this a limitation of the program. For modelling slabs should you generally always add edge restraints on all sides and then model the frame separately? Is there a way to model so that you can get both the slab and beam forces in one model that reflect hand calculations?

Thanks

 

[theshearstud]

Might be too late...but yes something is wrong. It seems as though you have not meshed your wall/slab. For this type of model, I would recommend the following:

1. Select Wall (Shell Element) -> Edit Menu -> Divide Area
2. Select Slab (Shell Element) -> Edit Menu -> Divide Area (be sure to use the same divisions as the wall along the perpendicular edge.

Dividing Shells or "Auto Meshing" is required for connectivity.

For the continuous one way slab, make sure your slab (shell element) has been drawn within the boundaries of your beams. Then either divide the slab (shell) area similar to above, or you can "Auto Mesh".

 

[theshearstud]

Do not restrain your shell element for these conditions.