I am unable to use joint check option in ductile column design in RCDC. The option is greyed out. Refer to screenshot below. What could be the possible reason for it.
Note: I already have run and designed all the beams in the model.
Can you please upload the .rcdx file here?
Thanks & regards,
Global Technical Support
I understood the issue. Actually there was no seismic load defined and the joint check is for seismic load combinations. Once I defined it, it worked fine.
But I did found some issues listed below:
1) When the column dimension is less than 300mm for ductile design, no warning has been observed to be given by RCDC. This violates the IS 13920:2016, Cl.7.1.1. Although its mentioned in HELP that it i will give warning, but none is seen and the design is shown as SAFE. Can you please share how and where the warning is shown?
2) IS 13920:2016, Cl.7.5 directs to compute shear forces in column based on the beams moment capacities framing into that column. Now, in column design module, RCDC doesn't take any input for the reinforcement of beam. What it is doing is, based on the end moments it calculates the required Ast and then as per that it selects appropriate bar dia and Ast provided. This might not always match with what actually is provided. May be if the beam is governed by crackwidth or deflection, Ast actually provided is more. Then in that case, beam moment capacity will be under estimated and consequently design shear force in column will also be under-estimated. Moreover, this under estimation of moment capacity of beam when compared with moment capacity of column (for weak beam and strong column concept to maintain capacity ratios of column to beam strength as 1.4) will yield incorrect results. Is there any way to take care of this?
3) this is a very minor issue. While giving user defined effective depth factors to column, it round offs the value to upto 2 decimal places if we give it separately for each column. But if we assign same value to all the columns using the assign to all option at the bottom of the table, then it take as much decimal places as is required. This leads to minor errors in the design calculations.
Do you found any answers to your queries? If yes, Please share