Shells with variable thickness

[farzad1366]

Dear all
I'm trying to model a shell with variable thickness in it's height. could anyone show me how to do this kind?
thanks a lot.

 

[Guest262653]

1 - Define a new joint pattern (Define --> Joint patterns)
2 - Assign to the joints a joint pattern with the thickness values (Assign --> Joint patterns)
3 - Assign to the shells the thickness overwrites (Assign --> Area --> Area Thickness Overwrites (Shells) --- User defined thickness specified by joint patterns)

 

[farzad1366]

Dear avscorreia
does it work with shell-layered/nonlinear? because when you want to define an element it is rectangular or circular, so there would be a constant radius over its height. Is it possible to define a cone like thing in sap with this one?
thanks a lot.

 

[Guest262653]

I really don't know. You'll have to try it.

 

[AmadoSan]

You know, I have seen this problem of multi-thickness shells/slabs over and over again. It is really a pain to model such things with the FEM due to the centerline modeling strategies. I see no other way to model such shells other than through the boundary element method.

 

[farzad1366]

so,at last would it be possible to make variable thickness shells in sap2000 and connect two different variable thickness shells together?

 

[Guest262653]

Have you tried the procedure I presented?

 

[stressed]

avscorreia's recommended procedure is exactly correct.

You can also use the area "thickness overwrites" option to 'move' the shell areas offset from centerline. For example, if you have a skid with a steel plate at the top or bottom of deep wide flange beams, you can model the shell centerline, then assign an area thickness overwrite to move it to the top or bottom flange location. It's similar to the insertion point assignment for frame elements.

 

[farzad1366]

i made the conical shell by rotating a line around z axis, so the point are in their correct position, then i made a join pattern and assigned cone's generator formula to the points. but it is confusing for me when i want to do something about the change of the thickness along z axis, i should make a different pattern for thickness and assign it to the points or i should do something else?
how it would be possible for me to check the right thicknesses which is assigned?