Best Way to Connect Shell-Solid Mesh for Hopper

[Doodler3D]

Hi,

I'm still learning FEA, I was keen to know the best way to connect a shell-solid mesh for a hopper. The sheet metal hopper section is a shell, whereas the flange is a solid. Does the shell mesh need a foundation that is around 2 to 3 layers thick? Any good books to find more information on this?

Thank you!

 

[rb1957]

if the flat member is 3D elements, these have only Fx, Fy, Fz freedoms at the nodes. whereas 2D plates have all 6 dofs.

if you connect to a line at the edge of the 3D plate, you're making a pinned joints (with no moment coming from the 3D solid plate into the 2D shell) … maybe this is your intention ?

more typically, make an RBE "spider" that picks up multiple layers on the 3D plate and joins to the 2D mid-plane.

another day in paradise, or is paradise one day closer ?

 

[Doodler3D]

rb1957,

I'm modeling a whole bin vessel, with the flange at the lower end. You mean I should add a rigid element between the outer flange surface (4 elements through flange) and the edge of the hopper? What if the hopper edge was bonded to the surface of the flange? Also would elements from the hopper penetrate the solid flange?

 

[MegaStructures]

For some reason I am having trouble seeing what the flange is that you are connecting the hopper, but rb is absolutely right. Nodes on solid elements only have translational degrees of freedom, so if you need to transfer moments at the interface you need a connection method other than merging the nodes at the interface. If you want a pinned surface than what you have shown is fine. If you want to transfer moment at the interface you have one or two options. Some codes, such as FEMAP, have the capability to glue the edge of a shell to the face of a solid. if your code doesn't have that capability rb's suggestion is my favorite where you connected all of the nodes on the surface of the solid to the nodes on the edge of the shell with rigid elements.

 

[Doodler3D]

Thank you MegaStructures.

 

[Mohanlal0488]

@DoodlerDaru

Why not just model the structure as sheet bodies and then bring it into your FEA environment?
Or unit and midsurface your geometry in a CAD environment and then bring it into your FEA environment.

 

[Doodler3D]

Mohanlal0488, Thanks. I'm remodeling the whole geometry with mid surfaces.