ASDShells vs SAP2000

[mike_oleary]

I'm wondering if anyone can describe the differences between the ASDShell elements and that used in SAP2000.

I've done some testing to try and determine the cause of the difference in results between that given by SAP2000. As far as I can tell the membrane behaviour is an exact match to that in SAP, however, the plate behaviour seems to differ (I believe the drilling dof also differs). Generally, any loading that results in plate behaviour differs from SAP.

If anyone is able to shed some light on what the differences could be that would be much appreciated.

In-plane comparison

inplane.png (42.82 KiB) Viewed 184 times

Out-of-plane comparison

outofplane.png (46.42 KiB) Viewed 184 times

[STKO Team]

ASDShellQ4 has the same plate bending behaviour of the MITC4 (shear deformable thick shell).
The DKGQ instead is for thin shells only (and should result in a stiffer behavior if used with realtively thick shells)
Regarding the ETABS one I don't know what they use.

Can you share the benchmark you did?