[Libmesh-users] Integration points through the thickness for shell elements

[Yuxiang W. <yw...@vi...>]

Dear all,

As one usually reads from literature (or commercial software
documentation), usually, a shell element would need >= 2 Gaussian
quadrature points through the thickness to capture its bending behavior.
For example, in the LS-DYNA documentation
<https://www.dynasupport.com/tutorial/ls-dyna-users-guide/elements> or
mentioned in this paper
<http://web.mit.edu/kjb/www/Principal_Publications/Performance_of_the_MITC3+_and_MITC4+_shell_elements_in_widely_used_benchmark_problems.pdf>
.

I noted that the QUADSHELL4 and QUADSHELL8 elements have only the 4
quadrature point at the zeta=0 plane. I was thinking about manually adding
one more layer for numerical integration, but just wonder that - would it
make sense to build that in QUADSHELL4 or QUADSHELL8 default qrule? Or
would you think it would be cleaner to manually add one more loop?

PS: The existing MITC4 shell example (actually Q4Gamma24 element) seems to
be using only one layer of quadrature points across the thickness, and the
results does not match ABAQUS well with thicker shells. I am still trying
to understand whether it is because of some small-strain assumptions during
implementation of the Q4Gamma24 theory, or whether it is because of the
1-layer integration points through the thickness. I'll report back when I
have an idea!

PPS: Reading a French textbook with Google Translate is really
challenging... :)

Best,
Shawn

-- 
Yuxiang "Shawn" Wang, PhD
yw...@vi...
+1 (434) 284-0836