ANSYS 12 Use of thin shells...which element type to use? 2

[stephenebrady]

I am modelling thin shell cylinders in ANSYS v12.
Several years ago we used to use 4noded shell63, but changed to the 8noded version Shell93.

Now ANSYS seems to have removed shell93 from the help manual(you can still use the element type), and seems to be suggesting that shell181 are the way to go, which is 4noded??

Any views on this?

 

[Stringmaker]

SHELL181 and SHELL281 are the most recent structural shell element types. Read the help on each and decide for yourself and your application. Both are excellent in my opinion.

 

[stephenebrady]

Cheers Stringmaker.

Any reason why shell93 is no longer the way to go?

 

[EngAddict]

Why only first order? Are you only calculating deflections or is it just to check your mesh? Do you use heavy refinement instead?

 

[stephenebrady]

Shell 93 is an 8noded element and we use it as a progression from the 4noded shell63 of old.

Using shell 181 which is back to a 4noded element seemed to be a bit of a backward step, which would require a refined mesh at local features.

 

[flash3780]

Seems like the Shell 281 is a newer formulation of a quadratic shell element (replacing Shell 93). Shell 181 seems like a newer formulation of a linear shell element (replacing Shell 63).

The Shell 281 element also seems to be able to handle layered properties (as used when modeling composite shells).

I haven't had an opportunity to try either of them out yet, though. That's just information from the help file.

 

[Stringmaker]

I haven't used either in a few months so all the specifics aren't fresh in my mind. Be sure to read and understand the restrictions and recommendations listed at the bottom section of the help file for each element. Also, as with all elements it pays to familiarize yourself with the keyoptions. I'm not always a fan of how Ansys configures the defaults for certain elements. I believe both 181 and 281 elements can handle layered applications. I have never utilized this capability though.

 

[stephenebrady]

Ok Thanks for your input.