Slab result interpretation

[meslija]

Hello,
Im a student.
I would like to understand better the results for slabs..
Is there a book about is?
Mostly i would like to know why is a difference between the analysis and the hand calculation.
What am i misunderstanding?
Thanks.

[bauskas]

Good question as for a student.

Main reason is that the slab calculations in FEA are, well, approximate. The elements' shape functions and other expressions are approximate and behave well only if your geometry is well-formed.

If you haven't seen the Verification manuals that come with Robot installation, take a look. They have some very vivid renderings of how structural mechanics problems are approximated in FEA.