i’m not really sure why the problem exist. but, firstly you need to plot the axial force of all truss element to understand is this has been distributed properly or not.
i see quickly from Mises stress, the distribution is not smoothed as expected. concerning at mid side nodes of shell element, may this is another causes of problems.
you can try to remove the truss element were connected to midside node of shell element and see the results.
I have reviewed all the orientations, mesh , set Ux and Uy =0 for the vertex node to see if that helped. Stress distribution is clearly not homogeneous because the truss doesn’t allow the lip to rotate.
There is something else which may help to identify the problem. The model is not invariant under rotation . It Is not the truss , the problem is with the elements aligned with the X axis.
I can see you have reproduced the model . ¿Could you give it a try and rotate it 90º around Z.?
restraining rotation of shell edge around the holes only make unreasonable results since naturally truss element did not allow to transmitted.
it seems the problem is not related to the axes, knot exist at there due to expansion of element and connection nodes.
reduce truss dimensions with higher stiffness eliminate the problems, however i’m not yet to check further in axial force distribution of truss element.
@xyont That’s the point. Nobady has restrain the rotation of the LIP. There is a bug on Trusses aligned with the X axis that makes them not to behave as truss.
We would need a circular plate with a perfect radial mesh to do that ¿isn’t it?
