I have a simple 2-D portal frame analysis of steel ISMB (Indian Steel Section).
Now code checking has given that the beam section has passed as matched with my manual calculation. But in the separate steel design tab, it shows beams as failed.
The difference what I have seen, in design tab while calculating the permissible bending stress, its takes the minimum ry values and not the rz value even if it was checking the moment about Z axis, This results in failure while in CODE CHECKING, the permissible bending stress about z axis calculated by taking the rz, even though the rz is greater that ry.
Why is it, will it not make more conservative. Please reply. Thanks
Note, For code checking in order to ignore the intermediate node points a suitable factor kZ is applied so that Lz X KZ will always be the length of the beam for each beam segments.
Note 2, It is assumed that main beam is connected to the secondary beams at intermediate points, so, the LZ is actually the length of each beam segments.Floor System Steel_Mt Connection.std
Jason Coleman, PE
Bentley Systems Senior Manager Technical Content