Learning Forum

[longt8]

Hello,

 

I have a question about the shell element "Upper Ipt Strain" and "Lowerr Ipt Strain". I have looked and went through the website https://ftp.lstc.com/anonymous/outgoing/support/FAQ/shellstrain

However, I have not make it clear about what is the different between "Upper Ipt Strain" and "Lowerr Ipt Strain".

 

Would you let me know does this respesent full integration point and reduced integration point strain value or the upper shell surface strain or lower shell surface strain value?

 

 

Thank you.

 

Best,

 

Teng

[Puneeth Bagaria]

Hello, 

A shell element may have multiple integration points through thickness defined under *SECTION_SHELL > NIP. The output of "upper" and "lower" Ipt strains correspond to strains in these integration points. 

The default integration scheme in LS-DYNA is gaussian which does not place integration points on the top and bottom surface of the shell element. Hence, they are not really the strains at top and bottom surfaces. You may refer to *SECTION_SHELL description in LS-DYNA manual volume-1 for more details on thickness integration.

Also, please refer to Shell Strain — Welcome to the LS-DYNA support site for a general overview of strain output for shell elements.

 

Regards

Puneeth