I am trying to attach shell elements with a solid meshed in tet elements using rutman fasteners, however, the fastener maker tool does not seem to work with this type of elements.
In all the material I have seen regarding this subject matter has used hex elements. And there is no explicit mention of limitations. So, its likely that tet elements are unsupported. Perhaps someone else would chime in and confirm.
I assume you are using the version of the fastener builder tool in the Patran Utility that supports shell and solid elements. this tool does support solids that are tet elements. however, there must be a row of nodes through the thickness of the solid at the fastener location. this is sometimes difficult to achieve with a tetmesh. you effectively have to split the solid at the fastener location so that you will get a row of nodes along the fastener shank.
Larry, you are right, we are using the fastener builder tool that supports the shell and solid elements. We manage to make it work for the tet elements (by splitting the solid before meshing).
However, we have noticed that meshing have created some small offset of the nodes with respect to the fastener axis (nodes are not exactly on the axis). For the nodes with offsets that are around 1E-4 off axis, we have large rotational displacements on the first solid node (on the side of the shell element). The AUTOSPC does not fix the rotational stiffness of those nodes.
I also noticed that the definition of the RBE2 are not the same in the fastener paper and the fastener presentation (ref.: KB8020230). In the presentation DOF 2,3,5,6 are applied to the RBE2 while only 2,3 are applied in the paper (and the utility).
We have tried to move the nodes on the axis (changed the reference coord system to the fastener axis system and changed the coord to 0. in the bdf) and loads in the bush are significantly different.
Are we supposed to impose an 456 SPC on the solid node?
Will the nudge node to axis option move the node exactly on the fastener axis or it will be within patran tolerance (~0.005)?
