Irregular panel map results for moment and shear at panel where panels join

[skellyRSA2023]

Hi, 

i was wondering could anyone help me, i have modelled the attached RC ground Chamber. The capping slab seems to give slightly strange panel maps for moments and shears where one slab panel connects to the other? i.e. very high shear and moment on side of the panel joint and low results on the other? as if they were not fully connected? however they seem to be by inspection. The panels where initially separate panels and i used the panel merge API to join them and this is the only joints in the capping slab which the API would not let me join. and they seem to be giving irregular results. Has anyone come across this before? Any help on the issue would be appreciated. 

Thanks, 

S. 

[Rafacascudo]

load 10 is a ULS combination .Loads 11 and 12 are the max and min envelopes for this ULS comb.

Showing maps for loads 10to12 does not make sense. The picture you sent is showing the maps for ULS- (load 12) and it is envelope , so it shows the minimum values for each of the FEs and most of the time ,it doesn´t have a logic sense. One FE maybe showing the value for a certain load component and its neighbor FE can be showing the value for a very different component.

Choose DL1 and you will see  smaller peak moments and shear.

Also , try a 10cm mesh and you will see big difference on moment and shear values and more smothness at the edges.

And also try "global smoothing" setting to make the forces at the neighbor edges more uniform

[skellyRSA2023]

Rafa, 

Thanks for getting back, i have used the 0.1m mesh spacing and the global smoothing etc. however i do come out with large shear values at the supports in kN/m for what is applied, what is the best way of obtaining these maximum moment and shear values at supports under ULS combination? would it be to use a panel cut along the length and reduced results values? How are others obtaining these results and what is the more realistic value rather than localized concentrated values as generally i would design a slab for a metre width at supports and midspan? 

S. 

[Rafacascudo · Accepted solution]

Yes,panel cuts. Set a cut not on the slab edge ,but on the face of the supporting wall (half wall thickness). Cut lenght should be at your criteria ,but not more than where the peak grows abruptly..

Forces should be read across the cut. So for shear it should be :

Direction X - local of the cut

Force - Qxx.

Then ,the integral value will give you the total shear force acting on the cut length