Not specific to Creo, but in general: What's the need of Mid-Surface?

[yogeshkulkarni]

Can we not use just one side of the Thin-wall part to crate Shell-elements?

Detailed query:
Why Midsurface? As its typically used for thin-walled parts, say, Sheet Metal, why not use just one side of the part, inside or outside, instead of extracting the Midsurface? Is there any L/T ratio below which either side is good enough as Midsurface?

 

[shaun8567]

When creating shell elements, you can use the top, mid, bottom, or user defined surface as the location for the shell elements. The effect of placing shell elements on either the top/bottom/user defined compare to the mid-surface will depend on the geometry of the structure, the thickness tied to the shell elements, and how accurate you want your results to be. Remember, when you can the placement of the shell elements, you are changing the place of the centroid of the part.

 

[yogeshkulkarni]

Thanks a lot.

 

[yogeshkulkarni]

more queries

What is considered as Thin-walled part? parameters for 'thin-ness'?

Where do you find Thin Wall parts - in Sheet Metal or Injection Moulding or Casting or Milling?

For which domain Midsurface is used most- consumer plastic , automotive ?

Which software has best Midsurface - Benchmarking?

Typical problems in creating midsurface and in the results ?

 

[shaun8567]

Q: What is considered as Thin-walled part? parameters for 'thin-ness'?
A: A decent rule of thumb is that the ratio of the shortest non-thickness dimension to the thickness is >= 10. Just remember that shell element theory is making some assumptions about the stress through the thickness of the part.

Q: Where do you find Thin Wall parts - in Sheet Metal or Injection Moulding or Casting or Milling?
A: Typically sheet-metal parts, but injection molded could also see the application. If by milling you mean machined part, then typically no.

Q: For which domain Midsurface is used most- consumer plastic , automotive ?
A: I'm not 100% sure what you mean by this, but if I understand you correctly, then automotive (lots of sheet-metal).

Q: Which software has best Midsurface - Benchmarking?
A: Shell element theory is pretty well defined, so I don't know if you can say there is a "best" when looking at solvers. Some solvers can do non-linear effects with shell element (Nastran for example) while others can't (Mechanica for example).

Q: Typical problems in creating midsurface and in the results ?
A: Usually creating the mid-surface is pretty straight forward; most CAD programs of pre-processors have the ability to auto-generate them. Again, the accuracy of the results depends on the geometry, connection, and results that you're after.

Did I just answer a bunch of homework questions?!

 

[yogeshkulkarni]

Thanks a lot for such a detailed reply.

BTW, I am not taking any course , so thats not for Homework. I am doing research in this topic thats why asked these preliminary questions.