Dear Dr. Koutras,

I really appreciate your insightful comments.

I tried the keyword deck *ELEMENT_BEAM and *SECTION_BEAM (setting ELFORM 1 and 3) before. For both of them, the results are presented below:

(as we can see, there are still small difference, like before, between the Hughes-Liu and the analytical solution, whereas the story is very much different for the truss element)!!!

At that time, it confused our team a lot, especially because the CFL limit was not satisfied and the output from LS-Dyna was very jagged compared to the analytical solution (you can see my conversation about troubleshooting it with Dr. Basu here: