Autodesk Robot Structural Analysis

[#1]

When verifying RC beam column joint for seismic analysis EC8. I have a scenario where I have both a lower and upper column, but in the automatic generation of the node only the lower column appears with all relevant combinations, as well as all the beams framing into the joint with envelope/combinations.

The upper column is not automatically added. I notice I can manually select the upper column, but the combinations cannot be automatically assigned (correct?) ... Now with hundreds of combinations to choose from, how does one "manually" create/modify the combinations in the node?

[#2]

Realized the issue was due to having plastic moments activated in the column seismic analysis.  

Question is how does one work around top storey columns (EC8) where node verification is not required but plastic moments need to be taken into consideration for shear verification.  Does one design the multi-storey top-floor column first without plastic moments to be able to verify the node at the column base and then check the design to see if it passes with plastic moments?  Or is there a simpler workaround?

[#3 · Accepted solution]

Stroxy,

You should have all columns and beams (that meet in the node you want to design) calculated (with generated reinforcement) before attempting to design the node itself. In such case the plastic moment should not be any obstacle.