Spars modeling

[CodingAircraft]

Good afternoon!
@A-CGray, can i ask a couple of questions?

If I understood correctly, you are modeling the ribs and spars, as well as the upper and lower panels. Could you please tell me how the spar caps are accounted for? Do you run stiffening ribs along the length of the spar, and does the stiffening rib simulate the spar caps?

[A-CGray]

There are no rib or spar caps in this model.

[CodingAircraft]

Thank you, can I ask another question?

In your papper: https://doi.org/10.2514/6.2023-3316. You give the overallstiffness matrix as:

Do I understand correctly, that As =

So A44 = 0 and Vy = 0?

I tried to search in the source code, but so far I don't have enough experience to figure it all out. I'll be very glad if you help with an answer.

[A-CGray]

Almost, there's no factor of 1/4 on that shear term, here are the equations including the transverse shear matrix:

This is done on this line in the source code.

A44 is zero in the stiffener matrix because the stiffeners don't add any stiffness against shearing in the 23 plane. But there is an A44 term in the shell stiffness matrix.

[CodingAircraft]

Thank you a lot!