PROBLEMS ADDING MASS TO A SHELL ELEMENT

[MIRomero]

Hello everyone,

I am trying to use Shell elements to define a tunnel under dynamic analysis. But I am having troubles if my analysis has shell elements with non-zero rho value and subjected to ground excitation.

My model has 1026 nodes and 988 elements.
Element type: ShellMITC4
Material: section ElasticMembranePlateSection 3 $E $nu $t $rho

It is running, but I have realized that it doesn't consider the mass density that I am imposing.

I saw the post: "Potential bugs in Shell element" by elhaddad from Thu Mar 20, 2014 in the forum.
Apparently someone had the problem previously and reported it.

Can you please let me know if there is an alternative way to include mass in a Shell element?
I need my tunnel model to be introduced in a soil model in the future.

Thank you,
Ma.Ines