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Issue with self-weight during optimization process

Hello,

I need to optimize a structure submitted to its self-weight and another hundred kg force. The self-weight (GRAV) does not allowed the convergence in DUAL mode (I do not have any access to DUAL2). I'm using the student Hyperworks 2017 edition. I tried to modifie the solver (MUMPS...) but there is no difference.

Thank you in advance for you help.

Baptiste

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Altair Forum User

Hi,

Can you share the entire .out file?

Altair Forum User

I do not have my pc with the licence so I can't check if it is the good file. But I think it is.

These are two models in 2D and 3D of a street light floor lamp.

Thank you very much.

Unable to find an attachment - read this blog

Altair Forum User

Hi,

I see feasible design (solution converged) in both out files.

Altair Forum User

Yes I know but the solution is not clean with a lot of checkerboard in the material and isolated areas. Is there anything to do to avoid self-weight issues ?

Altair Forum User

It looks like this while there is a force applied at the right edge...

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi,

Do you have any member size controls (minimum membersize/maximum membersize)?

If you have member size constraint, try to add CHECKER card on DOPTPRM

Altair Forum User

Hello,

I don't have any member size control. I tried to add one in DESVAR and modify some parameters in DOPTPRM, including CHECKER=1 but there isn't any improvement. Moreover, the result doesn't respect the maximum volume constraint. (I wonder if Optistruct is able to take the self-weight into account for topology optimization). Do I have to put a non-design area on the right edge to get density where the force is applied ? Here is the file I'm using to modelize the problem.

Thank you very much for your advice.