Topology Convergence problem
Rahul,
thanks for the answer. I have increased the no of iterations to 150. Now it converged, but the result is still very bad.
The displacement is -1.5e4 in the convergence graph. I dont know whats wrong...
Could you please check my model? I attached it in my first post.
Thanks for your help,
wan
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Can you have a lower bound like -2 or -3 units?
What you have is in positive direction. Give a constraints in negative direction component.
Hi @wan
Are you constraining the model some where in the middle?
If yes, then the results seems to be OK. If you observe the results, the nodes which are going into negative displacement are on the other side of the constraint.
So, due to moment of force, the nodes are tend to move in other direction of force (Something like a See-Saw)
Thank you for your reply. Yes ist like a See-Saw, but the negative displacement is very low in relation to the positive disp.
Anyway I have implement your proposal. The displacement constraint is now -2mm ... +2mm
But the result is the same: OPTIMIZATION HAS CONVERGED but INFEASIBLE DESIGN (AT LEAST ONE CONSTRAINT VIOLATED)
The optimization takes 845 iterations!
Could you take a look at my model please? I attached the .fem and the .out in a zip file
(please dont be confused, i named the constraint dispx, but it means y direction.. only the Name is wrong.)
My suggestion: Have two displacement responses. One for those nodes where you want to constrain the positive displacement
The other response for those nodes (on the other side of the model constraint) to constraint negative displacement.
Thank you for the suggestion. I have implement it but sadly with no success. The result is similar.
I think the problem has a different reason. I think it has something to do with the Minimum member size (mindim). Until now i have done every optimization with mindim 15.
Now i tried it without mindim and it works! The displacement curve looks good.
.
But now i would like to know why the mindim do not work? The average element size is 4mm. I tried mindim 15mm, 18mm, 20mm, and 25 mm.
Always i see those huge peaks in the displacement curve.
Can you help me again... Thank you
Hi Prakash,
thanks for your reply. You already have the latest version of my .
Nothing changed. I tried many variations but i get always the same bad result.
Can you estimate how long it will take to check this model with one of your experts?
Thank you
wan
Hi @wan,
Looks like You have only an upper bound but no lower bound. Can you create an upper and lower bound for your displacement constraints?
If you have only one bound, solver will only solve for that constraints. +Ve bound in your case.