In RCDC, for Beam ductile design using IS code, how is the ductile shear being calculated?
I have referred to RCDC help file as well as RCDC Beam FAQ (Q.31) given in the link below.
I am able to grasp the technical intent, but unable to validate the formulas as the values which I am computing using given formulas (refer below) are not matching with the RCDC output.
I also tried to find validation sheets for ductile beam design using IS code, but its not available. Only Non-ductile beam design validation is available.
I am also attaching a typical design for reference and and would appreciate if calculations using the same reference can be demonstrated.
While transferring loads from STAAD to RCDC for beams, the loads are not transferred exactly. Some deviation (although not significant) is observed in them. What could be the probable reason for the same?
First of all I would like to confirm if you are using the latest version of STAAD and RCDC? The latest versions are 22.08.00.175 and 11.01.00.180 respectively. If you are using any older version, please upgrade and check the issues specifically related to member forces.
However, if you still have the doubts please upload the STAAD, RCDX files along with your hand calculation for our quick check and investigation. Please also mention the query with relevant snaps for quick understanding. As it is difficult to answer any generic validation question.
VD+L is the value of 1.2*(DL+LL) as already mentioned. Code has suggested to take this value is sway shear calculation. If you are getting any other value in your calculation please send us the calculation to check.
However, you can download the validation for ductile shear from the below link.
Thanks & regards,
Global Technical Support
Currently I am using STAAD Connect update 4 (v22.05.00.131) and for RCDC I am using v9.04.00.128. I will try to get it updated.
But whatever STAAD validation file you shared, when I run the analysis with my STAAD version, still the values are not matching with the validation sheets. I request you to check and confirm once if in your STAAD version its matching.
Moreover, the calculation steps shown in validation sheets are quite helpful and i could figure out now how it is done in RCDC. So thank you for that.
I will ping back if any other doubt is there related to this.
I checked a few values and it is matching. Please upgrade and check. If you are seeing any mismatch please point it out for investigation.
I have updated to the newest version of both the softwares but still the forces between both doesnt match.
Attaching STAAD and RCDC files for your reference.
Also attaching the loads comparison between the two.
Please check to sort out the issue.
Load Comparison - STAAD vs RCDC.xlsx
The difference in results are very very small and should not have any effect in end results. I think you also agree the same. However, regarding numerical verification I do agree that the values should match exactly. We will look into this and try to fix any issue if present. However, you can carry on with your work as of now.
I agree that differences are minute and may not affect the end results. But when it does not match, it just don't give us the confidence that we require on the software. The difference will bother us and we will have no choice but to reverify the differences just to make sure its not significant. May be in the example i took, the differences are insignificant, but we will always be in a doubt for other designs we take. We are validating the software so that we can have confidence in it and want to use it to carry out our regular designs. Moreover, it will be extremely difficult to get the senior designers to agree on this point. So I request you to please look into it and sort it out in the coming revisions. If required, I can also raise a service request for the same.
Thank you for your support.
I completely agree to this point. I have already raised the issue internally with our developers. However a service request is always preferred and adds value to the request. If possible please create one.